[ES6] Implemented parse for export Name from Module variants. (#1701)

- add `AST_Export` new variants output
- add tests to `test/compress/`
- update `$propdoc` of `AST_Export` ("exported_names" & "module_name")
- add tests for `export ...  as ...` variants

.gitattributes

@@ -0,0 +1 @@
+*.js    text eol=lf

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,9 @@
+- Bug report or feature request? <!-- Note: sub-optimal but correct code is not a bug -->
+- `uglify-js` version (`uglifyjs -V`)
+- JavaScript input - ideally as small as possible.
+- The `uglifyjs` CLI command executed or `minify()` options used.
+- An example of JavaScript output produced and/or the error or warning.
+<!--
+    Note: the release version of uglify-js only supports ES5. Those wishing
+    to minify ES6 should use the experimental harmony branch.
+-->

.gitignore

@@ -1,2 +1,3 @@
+/node_modules/
+/npm-debug.log
 tmp/
-node_modules/

.travis.yml

@@ -0,0 +1,12 @@
+language: node_js
+before_install: "npm install -g npm"
+node_js:
+    - "0.10"
+    - "0.12"
+    - "4"
+    - "6"
+env:
+    - UGLIFYJS_TEST_ALL=1
+matrix:
+  fast_finish: true
+sudo: false

LICENSE

@@ -0,0 +1,29 @@
+UglifyJS is released under the BSD license:
+
+Copyright 2012-2013 (c) Mihai Bazon <mihai.bazon@gmail.com>
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above
+      copyright notice, this list of conditions and the following
+      disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials
+      provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.

README.md

@@ -1,5 +1,6 @@
 UglifyJS 2
 ==========
+[![Build Status](https://travis-ci.org/mishoo/UglifyJS2.svg)](https://travis-ci.org/mishoo/UglifyJS2)
 
 UglifyJS is a JavaScript parser, minifier, compressor or beautifier toolkit.
 
@@ -9,10 +10,22 @@ There's also an
 [in-browser online demo](http://lisperator.net/uglifyjs/#demo) (for Firefox,
 Chrome and probably Safari).
 
+#### Note:
+- release versions of `uglify-js` only support ECMAScript 5 (ES5). If you wish to minify
+ES2015+ (ES6+) code then please use the [harmony](#harmony) development branch.
+- Node 7 has a known performance regression and runs `uglify-js` twice as slow.
+
 Install
 -------
 
-From NPM:
+First make sure you have installed the latest version of [node.js](http://nodejs.org/)
+(You may need to restart your computer after this step).
+
+From NPM for use as a command line app:
+
+    npm install uglify-js -g
+
+From NPM for programmatic use:
 
     npm install uglify-js
 
@@ -36,49 +49,116 @@ variable/function declared in another file will be matched properly.
 If you want to read from STDIN instead, pass a single dash instead of input
 files.
 
+If you wish to pass your options before the input files, separate the two with
+a double dash to prevent input files being used as option arguments:
+
+    uglifyjs --compress --mangle -- input.js
+
 The available options are:
 
-    --source-map       Specify an output file where to generate source map.
-                                                                          [string]
-    --source-map-root  The path to the original source to be included in the
-                       source map.                                        [string]
-    --in-source-map    Input source map, useful if you're compressing JS that was
-                       generated from some other original code.
-    -p, --prefix       Skip prefix for original filenames that appear in source
-                       maps. For example -p 3 will drop 3 directories from file
-                       names and ensure they are relative paths.
-    -o, --output       Output file (default STDOUT).
-    -b, --beautify     Beautify output/specify output options.            [string]
-    -m, --mangle       Mangle names/pass mangler options.                 [string]
-    -r, --reserved     Reserved names to exclude from mangling.
-    -c, --compress     Enable compressor/pass compressor options. Pass options
-                       like -c hoist_vars=false,if_return=false. Use -c with no
-                       argument to use the default compression options.   [string]
-    -d, --define       Global definitions                                 [string]
-    --comments         Preserve copyright comments in the output. By default this
-                       works like Google Closure, keeping JSDoc-style comments
-                       that contain "@license" or "@preserve". You can optionally
-                       pass one of the following arguments to this flag:
-                       - "all" to keep all comments
-                       - a valid JS regexp (needs to start with a slash) to keep
-                       only comments that match.
-                       Note that currently not *all* comments can be kept when
-                       compression is on, because of dead code removal or
-                       cascading statements into sequences.               [string]
-    --stats            Display operations run time on STDERR.            [boolean]
-    --acorn            Use Acorn for parsing.                            [boolean]
-    --spidermonkey     Assume input fles are SpiderMonkey AST format (as JSON).
-                                                                         [boolean]
-    --self             Build itself (UglifyJS2) as a library (implies
-                       --wrap=UglifyJS --export-all)                     [boolean]
-    --wrap             Embed everything in a big function, making the “exports”
-                       and “global” variables available. You need to pass an
-                       argument to this option to specify the name that your
-                       module will take when included in, say, a browser.
-                                                                          [string]
-    --export-all       Only used when --wrap, this tells UglifyJS to add code to
-                       automatically export all globals.                 [boolean]
-    -v, --verbose      Verbose                                           [boolean]
+```
+  --source-map                  Specify an output file where to generate source
+                                map.
+  --source-map-root             The path to the original source to be included
+                                in the source map.
+  --source-map-url              The path to the source map to be added in //#
+                                sourceMappingURL.  Defaults to the value passed
+                                with --source-map.
+  --source-map-include-sources  Pass this flag if you want to include the
+                                content of source files in the source map as
+                                sourcesContent property.
+  --source-map-inline           Write base64-encoded source map to the end of js output.
+  --in-source-map               Input source map, useful if you're compressing
+                                JS that was generated from some other original
+                                code. Specify "inline" if the source map is included
+                                inline with the sources.
+  --screw-ie8                   Use this flag if you don't wish to support
+                                Internet Explorer 6/7/8.
+                                By default UglifyJS will not try to be IE-proof.
+  --support-ie8                 Use this flag to support Internet Explorer 6/7/8.
+                                Equivalent to setting `screw_ie8: false` in `minify()`
+                                for `compress`, `mangle` and `output` options.
+  --expr                        Parse a single expression, rather than a
+                                program (for parsing JSON)
+  -p, --prefix                  Skip prefix for original filenames that appear
+                                in source maps. For example -p 3 will drop 3
+                                directories from file names and ensure they are
+                                relative paths. You can also specify -p
+                                relative, which will make UglifyJS figure out
+                                itself the relative paths between original
+                                sources, the source map and the output file.
+  -o, --output                  Output file (default STDOUT).
+  -b, --beautify                Beautify output/specify output options.
+  -m, --mangle                  Mangle names/pass mangler options.
+  -r, --reserved                Reserved names to exclude from mangling.
+  -c, --compress                Enable compressor/pass compressor options, e.g.
+                                `-c 'if_return=false,pure_funcs=["Math.pow","console.log"]'`
+                                Use `-c` with no argument to enable default compression
+                                options.
+  -d, --define                  Global definitions
+  -e, --enclose                 Embed everything in a big function, with a
+                                configurable parameter/argument list.
+  --comments                    Preserve copyright comments in the output. By
+                                default this works like Google Closure, keeping
+                                JSDoc-style comments that contain "@license" or
+                                "@preserve". You can optionally pass one of the
+                                following arguments to this flag:
+                                - "all" to keep all comments
+                                - a valid JS RegExp like `/foo/` or `/^!/` to
+                                keep only matching comments.
+                                Note that currently not *all* comments can be
+                                kept when compression is on, because of dead
+                                code removal or cascading statements into
+                                sequences.
+  --preamble                    Preamble to prepend to the output.  You can use
+                                this to insert a comment, for example for
+                                licensing information.  This will not be
+                                parsed, but the source map will adjust for its
+                                presence.
+  --stats                       Display operations run time on STDERR.
+  --acorn                       Use Acorn for parsing.
+  --spidermonkey                Assume input files are SpiderMonkey AST format
+                                (as JSON).
+  --self                        Build itself (UglifyJS2) as a library (implies
+                                --wrap=UglifyJS --export-all)
+  --wrap                        Embed everything in a big function, making the
+                                “exports” and “global” variables available. You
+                                need to pass an argument to this option to
+                                specify the name that your module will take
+                                when included in, say, a browser.
+  --export-all                  Only used when --wrap, this tells UglifyJS to
+                                add code to automatically export all globals.
+  --lint                        Display some scope warnings
+  -v, --verbose                 Verbose
+  -V, --version                 Print version number and exit.
+  --noerr                       Don't throw an error for unknown options in -c,
+                                -b or -m.
+  --bare-returns                Allow return outside of functions.  Useful when
+                                minifying CommonJS modules and Userscripts that
+                                may be anonymous function wrapped (IIFE) by the
+                                .user.js engine `caller`.
+  --keep-fnames                 Do not mangle/drop function names.  Useful for
+                                code relying on Function.prototype.name.
+  --reserved-file               File containing reserved names
+  --reserve-domprops            Make (most?) DOM properties reserved for
+                                --mangle-props
+  --mangle-props                Mangle property names (default `0`). Set to
+                                `true` or `1` to mangle all property names. Set
+                                to `unquoted` or `2` to only mangle unquoted
+                                property names. Mode `2` also enables the
+                                `keep_quoted_props` beautifier option to
+                                preserve the quotes around property names and
+                                disables the `properties` compressor option to
+                                prevent rewriting quoted properties with dot
+                                notation. You can override these by setting
+                                them explicitly on the command line.
+  --mangle-regex                Only mangle property names matching the regex
+  --name-cache                  File to hold mangled names mappings
+  --pure-funcs                  Functions that can be safely removed if their
+                                return value is not used, e.g.
+                                `--pure-funcs Math.floor console.info`
+                                (requires `--compress`)
+```
 
 Specify `--output` (`-o`) to declare the output file.  Otherwise the output
 goes to STDOUT.
@@ -123,18 +203,21 @@ compressed JS by mapping every token in the compiled JS to its original
 location.
 
 To use this feature you need to pass `--in-source-map
-/path/to/input/source.map`.  Normally the input source map should also point
-to the file containing the generated JS, so if that's correct you can omit
-input files from the command line.
+/path/to/input/source.map` or `--in-source-map inline` if the source map is
+included inline with the sources. Normally the input source map should also
+point to the file containing the generated JS, so if that's correct you can
+omit input files from the command line.
 
 ## Mangler options
 
-To enable the mangler you need to pass `--mangle` (`-m`).  Optionally you
-can pass `-m sort` (we'll possibly have other flags in the future) in order
-to assign shorter names to most frequently used variables.  This saves a few
-hundred bytes on jQuery before gzip, but the output is _bigger_ after gzip
-(and seems to happen for other libraries I tried it on) therefore it's not
-enabled by default.
+To enable the mangler you need to pass `--mangle` (`-m`).  The following
+(comma-separated) options are supported:
+
+- `toplevel` — mangle names declared in the toplevel scope (disabled by
+  default).
+
+- `eval` — mangle names visible in scopes where `eval` or `with` are used
+  (disabled by default).
 
 When mangling is enabled but you want to prevent certain names from being
 mangled, you can declare those names with `--reserved` (`-r`) — pass a
@@ -144,6 +227,99 @@ comma-separated list of names.  For example:
 
 to prevent the `require`, `exports` and `$` names from being changed.
 
+### Mangling property names (`--mangle-props`)
+
+**Note:** this will probably break your code.  Mangling property names is a
+separate step, different from variable name mangling.  Pass
+`--mangle-props`.  It will mangle all properties that are seen in some
+object literal, or that are assigned to.  For example:
+
+```js
+var x = {
+  foo: 1
+};
+
+x.bar = 2;
+x["baz"] = 3;
+x[condition ? "moo" : "boo"] = 4;
+console.log(x.something());
+```
+
+In the above code, `foo`, `bar`, `baz`, `moo` and `boo` will be replaced
+with single characters, while `something()` will be left as is.
+
+In order for this to be of any use, we should avoid mangling standard JS
+names.  For instance, if your code would contain `x.length = 10`, then
+`length` becomes a candidate for mangling and it will be mangled throughout
+the code, regardless if it's being used as part of your own objects or
+accessing an array's length.  To avoid that, you can use `--reserved-file`
+to pass a filename that should contain the names to be excluded from
+mangling.  This file can be used both for excluding variable names and
+property names.  It could look like this, for example:
+
+```js
+{
+  "vars": [ "define", "require", ... ],
+  "props": [ "length", "prototype", ... ]
+}
+```
+
+`--reserved-file` can be an array of file names (either a single
+comma-separated argument, or you can pass multiple `--reserved-file`
+arguments) — in this case it will exclude names from all those files.
+
+A default exclusion file is provided in `tools/domprops.json` which should
+cover most standard JS and DOM properties defined in various browsers.  Pass
+`--reserve-domprops` to read that in.
+
+You can also use a regular expression to define which property names should be
+mangled.  For example, `--mangle-regex="/^_/"` will only mangle property names
+that start with an underscore.
+
+When you compress multiple files using this option, in order for them to
+work together in the end we need to ensure somehow that one property gets
+mangled to the same name in all of them.  For this, pass `--name-cache
+filename.json` and UglifyJS will maintain these mappings in a file which can
+then be reused.  It should be initially empty.  Example:
+
+```
+rm -f /tmp/cache.json  # start fresh
+uglifyjs file1.js file2.js --mangle-props --name-cache /tmp/cache.json -o part1.js
+uglifyjs file3.js file4.js --mangle-props --name-cache /tmp/cache.json -o part2.js
+```
+
+Now, `part1.js` and `part2.js` will be consistent with each other in terms
+of mangled property names.
+
+Using the name cache is not necessary if you compress all your files in a
+single call to UglifyJS.
+
+#### Mangling unquoted names (`--mangle-props=unquoted` or `--mangle-props=2`)
+
+Using quoted property name (`o["foo"]`) reserves the property name (`foo`)
+so that it is not mangled throughout the entire script even when used in an
+unquoted style (`o.foo`). Example:
+
+```
+$ echo 'var o={"foo":1, bar:3}; o.foo += o.bar; console.log(o.foo);' | uglifyjs --mangle-props=2 -mc
+var o={"foo":1,a:3};o.foo+=o.a,console.log(o.foo);
+```
+
+#### Debugging property name mangling
+
+You can also pass `--mangle-props-debug` in order to mangle property names
+without completely obscuring them. For example the property `o.foo`
+would mangle to `o._$foo$_` with this option. This allows property mangling
+of a large codebase while still being able to debug the code and identify
+where mangling is breaking things.
+
+You can also pass a custom suffix using `--mangle-props-debug=XYZ`. This would then
+mangle `o.foo` to `o._$foo$XYZ_`. You can change this each time you compile a
+script to identify how a property got mangled. One technique is to pass a
+random number on every compile to simulate mangling changing with different
+inputs (e.g. as you update the input script with new properties), and to help
+identify mistakes like writing mangled keys to storage.
+
 ## Compressor options
 
 You need to pass `--compress` (`-c`) to enable the compressor.  Optionally
@@ -151,46 +327,151 @@ you can pass a comma-separated list of options.  Options are in the form
 `foo=bar`, or just `foo` (the latter implies a boolean option that you want
 to set `true`; it's effectively a shortcut for `foo=true`).
 
-The defaults should be tuned for maximum compression on most code.  Here are
-the available options (all are `true` by default, except `hoist_vars`):
+- `sequences` (default: true) -- join consecutive simple statements using the
+  comma operator.  May be set to a positive integer to specify the maximum number
+  of consecutive comma sequences that will be generated. If this option is set to
+  `true` then the default `sequences` limit is `200`. Set option to `false` or `0`
+  to disable. The smallest `sequences` length is `2`. A `sequences` value of `1`
+  is grandfathered to be equivalent to `true` and as such means `200`. On rare
+  occasions the default sequences limit leads to very slow compress times in which
+  case a value of `20` or less is recommended.
 
-- `sequences` -- join consecutive simple statements using the comma operator
 - `properties` -- rewrite property access using the dot notation, for
   example `foo["bar"] → foo.bar`
-- `dead-code` -- remove unreachable code
-- `drop-debugger` -- remove `debugger;` statements
-- `unsafe` -- apply "unsafe" transformations (discussion below)
+
+- `dead_code` -- remove unreachable code
+
+- `drop_debugger` -- remove `debugger;` statements
+
+- `unsafe` (default: false) -- apply "unsafe" transformations (discussion below)
+
+- `unsafe_comps` (default: false) -- Reverse `<` and `<=` to `>` and `>=` to
+  allow improved compression. This might be unsafe when an at least one of two
+  operands is an object with computed values due the use of methods like `get`,
+  or `valueOf`. This could cause change in execution order after operands in the
+  comparison are switching. Compression only works if both `comparisons` and
+  `unsafe_comps` are both set to true.
+
+- `unsafe_math` (default: false) -- optimize numerical expressions like
+  `2 * x * 3` into `6 * x`, which may give imprecise floating point results.
+
+- `unsafe_proto` (default: false) -- optimize expressions like
+  `Array.prototype.slice.call(a)` into `[].slice.call(a)`
+
 - `conditionals` -- apply optimizations for `if`-s and conditional
   expressions
+
 - `comparisons` -- apply certain optimizations to binary nodes, for example:
-  `!(a <= b) → a > b` (only when `unsafe`), attempts to negate binary nodes,
-  e.g. `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
+  `!(a <= b) → a > b` (only when `unsafe_comps`), attempts to negate binary
+  nodes, e.g. `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.
+
 - `evaluate` -- attempt to evaluate constant expressions
+
 - `booleans` -- various optimizations for boolean context, for example `!!a
   ? b : c → a ? b : c`
+
 - `loops` -- optimizations for `do`, `while` and `for` loops when we can
   statically determine the condition
-- `unused` -- drop unreferenced functions and variables
-- `hoist-funs` -- hoist function declarations
-- `hoist-vars` -- hoist `var` declarations (this is `false` by default
-  because it seems to increase the size of the output in general)
-- `if-return` -- optimizations for if/return and if/continue
-- `join-vars` -- join consecutive `var` statements
+
+- `unused` -- drop unreferenced functions and variables (simple direct variable
+  assignments do not count as references unless set to `"keep_assign"`)
+
+- `toplevel` -- drop unreferenced functions (`"funcs"`) and/or variables (`"vars"`)
+  in the toplevel scope (`false` by default, `true` to drop both unreferenced
+  functions and variables)
+
+- `top_retain` -- prevent specific toplevel functions and variables from `unused`
+  removal (can be array, comma-separated, RegExp or function. Implies `toplevel`)
+
+- `hoist_funs` -- hoist function declarations
+
+- `hoist_vars` (default: false) -- hoist `var` declarations (this is `false`
+  by default because it seems to increase the size of the output in general)
+
+- `if_return` -- optimizations for if/return and if/continue
+
+- `join_vars` -- join consecutive `var` statements
+
 - `cascade` -- small optimization for sequences, transform `x, x` into `x`
   and `x = something(), x` into `x = something()`
+
+- `collapse_vars` -- Collapse single-use `var` and `const` definitions
+  when possible.
+
+- `reduce_vars` -- Improve optimization on variables assigned with and
+  used as constant values.
+
 - `warnings` -- display warnings when dropping unreachable code or unused
   declarations etc.
 
+- `negate_iife` -- negate "Immediately-Called Function Expressions"
+  where the return value is discarded, to avoid the parens that the
+  code generator would insert.
+
+- `pure_getters` -- the default is `false`.  If you pass `true` for
+  this, UglifyJS will assume that object property access
+  (e.g. `foo.bar` or `foo["bar"]`) doesn't have any side effects.
+
+- `pure_funcs` -- default `null`.  You can pass an array of names and
+  UglifyJS will assume that those functions do not produce side
+  effects.  DANGER: will not check if the name is redefined in scope.
+  An example case here, for instance `var q = Math.floor(a/b)`.  If
+  variable `q` is not used elsewhere, UglifyJS will drop it, but will
+  still keep the `Math.floor(a/b)`, not knowing what it does.  You can
+  pass `pure_funcs: [ 'Math.floor' ]` to let it know that this
+  function won't produce any side effect, in which case the whole
+  statement would get discarded.  The current implementation adds some
+  overhead (compression will be slower).
+
+- `drop_console` -- default `false`.  Pass `true` to discard calls to
+  `console.*` functions. If you wish to drop a specific function call
+  such as `console.info` and/or retain side effects from function arguments
+  after dropping the function call then use `pure_funcs` instead.
+
+- `expression` -- default `false`.  Pass `true` to preserve completion values
+  from terminal statements without `return`, e.g. in bookmarklets.
+
+- `keep_fargs` -- default `true`.  Prevents the
+  compressor from discarding unused function arguments.  You need this
+  for code which relies on `Function.length`.
+
+- `keep_fnames` -- default `false`.  Pass `true` to prevent the
+  compressor from discarding function names.  Useful for code relying on
+  `Function.prototype.name`. See also: the `keep_fnames` [mangle option](#mangle).
+
+- `passes` -- default `1`. Number of times to run compress. Use an
+  integer argument larger than 1 to further reduce code size in some cases.
+  Note: raising the number of passes will increase uglify compress time.
+
+### The `unsafe` option
+
+It enables some transformations that *might* break code logic in certain
+contrived cases, but should be fine for most code.  You might want to try it
+on your own code, it should reduce the minified size.  Here's what happens
+when this flag is on:
+
+- `new Array(1, 2, 3)` or `Array(1, 2, 3)` → `[ 1, 2, 3 ]`
+- `new Object()` → `{}`
+- `String(exp)` or `exp.toString()` → `"" + exp`
+- `new Object/RegExp/Function/Error/Array (...)` → we discard the `new`
+- `typeof foo == "undefined"` → `foo === void 0`
+- `void 0` → `undefined` (if there is a variable named "undefined" in
+  scope; we do it because the variable name will be mangled, typically
+  reduced to a single character)
+
 ### Conditional compilation
 
 You can use the `--define` (`-d`) switch in order to declare global
 variables that UglifyJS will assume to be constants (unless defined in
 scope).  For example if you pass `--define DEBUG=false` then, coupled with
 dead code removal UglifyJS will discard the following from the output:
+```javascript
+if (DEBUG) {
+	console.log("debug stuff");
+}
+```
 
-    if (DEBUG) {
-        console.log("debug stuff");
-    }
+You can specify nested constants in the form of `--define env.DEBUG=false`.
 
 UglifyJS will warn about the condition being always false and about dropping
 unreachable code; for now there is no option to turn off only this specific
@@ -199,10 +480,11 @@ warning, you can pass `warnings=false` to turn off *all* warnings.
 Another way of doing that is to declare your globals as constants in a
 separate file and include it into the build.  For example you can have a
 `build/defines.js` file with the following:
-
-    const DEBUG = false;
-    const PRODUCTION = true;
-    // etc.
+```javascript
+const DEBUG = false;
+const PRODUCTION = true;
+// etc.
+```
 
 and build your code like this:
 
@@ -210,8 +492,26 @@ and build your code like this:
 
 UglifyJS will notice the constants and, since they cannot be altered, it
 will evaluate references to them to the value itself and drop unreachable
-code as usual.  The possible downside of this approach is that the build
-will contain the `const` declarations.
+code as usual.  The build will contain the `const` declarations if you use
+them. If you are targeting < ES6 environments which does not support `const`,
+using `var` with `reduce_vars` (enabled by default) should suffice.
+
+<a name="codegen-options"></a>
+
+#### Conditional compilation, API
+You can also use conditional compilation via the programmatic API. With the difference that the
+property name is `global_defs` and is a compressor property:
+
+```js
+uglifyJS.minify([ "input.js"], {
+    compress: {
+        dead_code: true,
+        global_defs: {
+            DEBUG: false
+        }
+    }
+});
+```
 
 ## Beautifier options
 
@@ -229,7 +529,7 @@ can pass additional arguments that control the code output:
   objects
 - `space-colon` (default `true`) -- insert a space after the colon signs
 - `ascii-only` (default `false`) -- escape Unicode characters in strings and
-  regexps
+  regexps (affects directives with non-ascii characters becoming invalid)
 - `inline-script` (default `false`) -- escape the slash in occurrences of
   `</script` in strings
 - `width` (default 80) -- only takes effect when beautification is on, this
@@ -238,9 +538,6 @@ can pass additional arguments that control the code output:
   It doesn't work very well currently, but it does make the code generated
   by UglifyJS more readable.
 - `max-line-len` (default 32000) -- maximum line length (for uglified code)
-- `ie-proof` (default `true`) -- generate “IE-proof” code (for now this
-  means add brackets around the do/while in code like this: `if (foo) do
-  something(); while (bar); else ...`.
 - `bracketize` (default `false`) -- always insert brackets in `if`, `for`,
   `do`, `while` or `with` statements, even if their body is a single
   statement.
@@ -248,6 +545,22 @@ can pass additional arguments that control the code output:
   you pass `false` then whenever possible we will use a newline instead of a
   semicolon, leading to more readable output of uglified code (size before
   gzip could be smaller; size after gzip insignificantly larger).
+- `preamble` (default `null`) -- when passed it must be a string and
+  it will be prepended to the output literally.  The source map will
+  adjust for this text.  Can be used to insert a comment containing
+  licensing information, for example.
+- `quote_style` (default `0`) -- preferred quote style for strings (affects
+  quoted property names and directives as well):
+  - `0` -- prefers double quotes, switches to single quotes when there are
+    more double quotes in the string itself.
+  - `1` -- always use single quotes
+  - `2` -- always use double quotes
+  - `3` -- always use the original quotes
+- `keep_quoted_props` (default `false`) -- when turned on, prevents stripping
+  quotes from property names in object literals.
+- `ecma` (default `5`) -- set output printing mode.  This will only change the
+  output in direct control of the beautifier.  Non-compatible features in the
+  abstract syntax tree will still be outputted as is.
 
 ### Keeping copyright notices or other comments
 
@@ -260,14 +573,15 @@ keep only comments that match this regexp.  For example `--comments
 
 Note, however, that there might be situations where comments are lost.  For
 example:
-
-    function f() {
-      /** @preserve Foo Bar */
-      function g() {
-        // this function is never called
-      }
-      return something();
-    }
+```javascript
+function f() {
+	/** @preserve Foo Bar */
+	function g() {
+	  // this function is never called
+	}
+	return something();
+}
+```
 
 Even though it has "@preserve", the comment will be lost because the inner
 function `g` (which is the AST node to which the comment is attached to) is
@@ -304,13 +618,46 @@ Acorn is really fast (e.g. 250ms instead of 380ms on some 650K code), but
 converting the SpiderMonkey tree that Acorn produces takes another 150ms so
 in total it's a bit more than just using UglifyJS's own parser.
 
+### Using UglifyJS to transform SpiderMonkey AST
+
+Now you can use UglifyJS as any other intermediate tool for transforming
+JavaScript ASTs in SpiderMonkey format.
+
+Example:
+
+```javascript
+function uglify(ast, options, mangle) {
+  // Conversion from SpiderMonkey AST to internal format
+  var uAST = UglifyJS.AST_Node.from_mozilla_ast(ast);
+
+  // Compression
+  uAST.figure_out_scope();
+  uAST = UglifyJS.Compressor(options).compress(uAST);
+
+  // Mangling (optional)
+  if (mangle) {
+    uAST.figure_out_scope();
+    uAST.compute_char_frequency();
+    uAST.mangle_names();
+  }
+
+  // Back-conversion to SpiderMonkey AST
+  return uAST.to_mozilla_ast();
+}
+```
+
+Check out
+[original blog post](http://rreverser.com/using-mozilla-ast-with-uglifyjs/)
+for details.
+
 API Reference
 -------------
 
 Assuming installation via NPM, you can load UglifyJS in your application
 like this:
-
-    var UglifyJS = require("uglify-js");
+```javascript
+var UglifyJS = require("uglify-js");
+```
 
 It exports a lot of names, but I'll discuss here the basics that are needed
 for parsing, mangling and compressing a piece of code.  The sequence is (1)
@@ -321,54 +668,154 @@ parse, (2) compress, (3) mangle, (4) generate output code.
 There's a single toplevel function which combines all the steps.  If you
 don't need additional customization, you might want to go with `minify`.
 Example:
-
-    // see "fromString" below if you need to pass code instead of file name
-    var result = UglifyJS.minify("/path/to/file.js");
-    console.log(result.code); // minified output
+```javascript
+var result = UglifyJS.minify("/path/to/file.js");
+console.log(result.code); // minified output
+// if you need to pass code instead of file name
+var result = UglifyJS.minify("var b = function () {};", {fromString: true});
+```
 
 You can also compress multiple files:
-
-    var result = UglifyJS.minify([ "file1.js", "file2.js", "file3.js" ]);
-    console.log(result.code);
+```javascript
+var result = UglifyJS.minify([ "file1.js", "file2.js", "file3.js" ]);
+console.log(result.code);
+```
 
 To generate a source map:
+```javascript
+var result = UglifyJS.minify([ "file1.js", "file2.js", "file3.js" ], {
+	outSourceMap: "out.js.map"
+});
+console.log(result.code); // minified output
+console.log(result.map);
+```
 
-    var result = UglifyJS.minify([ "file1.js", "file2.js", "file3.js" ], {
-        outSourceMap: "out.js.map"
-    });
-    console.log(result.code); // minified output
-    console.log(result.map);
+To generate a source map with the fromString option, you can also use an object:
+```javascript
+var result = UglifyJS.minify({"file1.js": "var a = function () {};"}, {
+  outSourceMap: "out.js.map",
+  outFileName: "out.js",
+  fromString: true
+});
+```
 
 Note that the source map is not saved in a file, it's just returned in
-`result.map`.  The value passed for `outSourceMap` is only used to set the
-`file` attribute in the source map (see [the spec][sm-spec]).
+`result.map`.  The value passed for `outSourceMap` is only used to set
+`//# sourceMappingURL=out.js.map` in `result.code`. The value of
+`outFileName` is only used to set `file` attribute in source map file.
+
+The `file` attribute in the source map (see [the spec][sm-spec]) will
+use `outFileName` firstly, if it's falsy, then will be deduced from
+`outSourceMap` (by removing `'.map'`).
+
+You can set option `sourceMapInline` to be `true` and source map will
+be appended to code.
 
 You can also specify sourceRoot property to be included in source map:
-
-    var result = UglifyJS.minify([ "file1.js", "file2.js", "file3.js" ], {
-        outSourceMap: "out.js.map",
-        sourceRoot: "http://example.com/src"
-    });
-
+```javascript
+var result = UglifyJS.minify([ "file1.js", "file2.js", "file3.js" ], {
+	outSourceMap: "out.js.map",
+	sourceRoot: "http://example.com/src"
+});
+```
 
 If you're compressing compiled JavaScript and have a source map for it, you
 can use the `inSourceMap` argument:
+```javascript
+var result = UglifyJS.minify("compiled.js", {
+	inSourceMap: "compiled.js.map",
+	outSourceMap: "minified.js.map"
+});
+// same as before, it returns `code` and `map`
+```
 
-    var result = UglifyJS.minify("compiled.js", {
-        inSourceMap: "compiled.js.map",
-        outSourceMap: "minified.js.map"
-    });
-    // same as before, it returns `code` and `map`
+If your input source map is not in a file, you can pass it in as an object
+using the `inSourceMap` argument:
+
+```javascript
+var result = UglifyJS.minify("compiled.js", {
+	inSourceMap: JSON.parse(my_source_map_string),
+	outSourceMap: "minified.js.map"
+});
+```
 
 The `inSourceMap` is only used if you also request `outSourceMap` (it makes
 no sense otherwise).
 
+To set the source map url, use the `sourceMapUrl` option.
+If you're using the X-SourceMap header instead, you can just set the `sourceMapUrl` option to false.
+Defaults to outSourceMap:
+
+```javascript
+var result = UglifyJS.minify([ "file1.js" ], {
+  outSourceMap: "out.js.map",
+  sourceMapUrl: "localhost/out.js.map"
+});
+```
+
 Other options:
 
 - `warnings` (default `false`) — pass `true` to display compressor warnings.
+
 - `fromString` (default `false`) — if you pass `true` then you can pass
   JavaScript source code, rather than file names.
 
+- `mangle` (default `true`) — pass `false` to skip mangling names, or pass
+  an object to specify mangling options (see below).
+
+- `mangleProperties` (default `false`) — pass an object to specify custom
+  mangle property options.
+
+- `output` (default `null`) — pass an object if you wish to specify
+  additional [output options][codegen].  The defaults are optimized
+  for best compression.
+
+- `compress` (default `{}`) — pass `false` to skip compressing entirely.
+  Pass an object to specify custom [compressor options][compressor].
+
+- `parse` (default {}) — pass an object if you wish to specify some
+  additional [parser options][parser]. (not all options available... see below)
+
+##### mangle
+
+ - `except` - pass an array of identifiers that should be excluded from mangling
+
+ - `toplevel` — mangle names declared in the toplevel scope (disabled by
+  default).
+
+ - `eval` — mangle names visible in scopes where eval or with are used
+  (disabled by default).
+
+ - `keep_fnames` -- default `false`.  Pass `true` to not mangle
+  function names.  Useful for code relying on `Function.prototype.name`.
+  See also: the `keep_fnames` [compress option](#compressor-options).
+
+  Examples:
+
+  ```javascript
+  //tst.js
+  var globalVar;
+  function funcName(firstLongName, anotherLongName)
+  {
+    var myVariable = firstLongName +  anotherLongName;
+  }
+
+  UglifyJS.minify("tst.js").code;
+  // 'function funcName(a,n){}var globalVar;'
+
+  UglifyJS.minify("tst.js", { mangle: { except: ['firstLongName'] } }).code;
+  // 'function funcName(firstLongName,a){}var globalVar;'
+
+  UglifyJS.minify("tst.js", { mangle: { toplevel: true } }).code;
+  // 'function n(n,a){}var a;'
+  ```
+
+##### mangleProperties options
+
+ - `regex` — Pass a RegExp to only mangle certain names (maps to the `--mangle-regex` CLI arguments option)
+ - `ignore_quoted` – Only mangle unquoted property names (maps to the `--mangle-props 2` CLI arguments option)
+ - `debug` – Mangle names with the original name still present (maps to the `--mangle-props-debug` CLI arguments option). Defaults to `false`. Pass an empty string to enable, or a non-empty string to set the suffix.
+
 We could add more options to `UglifyJS.minify` — if you need additional
 functionality please suggest!
 
@@ -378,14 +825,18 @@ Following there's more detailed API info, in case the `minify` function is
 too simple for your needs.
 
 #### The parser
-
-    var toplevel_ast = UglifyJS.parse(code, options);
+```javascript
+var toplevel_ast = UglifyJS.parse(code, options);
+```
 
 `options` is optional and if present it must be an object.  The following
 properties are available:
 
 - `strict` — disable automatic semicolon insertion and support for trailing
   comma in arrays and objects
+- `bare_returns` — Allow return outside of functions. (maps to the
+  `--bare-returns` CLI arguments option and available to `minify` `parse`
+  other options object)
 - `filename` — the name of the file where this code is coming from
 - `toplevel` — a `toplevel` node (as returned by a previous invocation of
   `parse`)
@@ -393,15 +844,16 @@ properties are available:
 The last two options are useful when you'd like to minify multiple files and
 get a single file as the output and a proper source map.  Our CLI tool does
 something like this:
-
-    var toplevel = null;
-    files.forEach(function(file){
-        var code = fs.readFileSync(file);
-        toplevel = UglifyJS.parse(code, {
-            filename: file,
-            toplevel: toplevel
-        });
-    });
+```javascript
+var toplevel = null;
+files.forEach(function(file){
+	var code = fs.readFileSync(file, "utf8");
+	toplevel = UglifyJS.parse(code, {
+		filename: file,
+		toplevel: toplevel
+	});
+});
+```
 
 After this, we have in `toplevel` a big AST containing all our files, with
 each token having proper information about where it came from.
@@ -415,15 +867,17 @@ referenced, if it is a global or not, if a function is using `eval` or the
 `with` statement etc.  I will discuss this some place else, for now what's
 important to know is that you need to call the following before doing
 anything with the tree:
-
-    toplevel.figure_out_scope()
+```javascript
+toplevel.figure_out_scope()
+```
 
 #### Compression
 
 Like this:
-
-    var compressor = UglifyJS.Compressor(options);
-    var compressed_ast = toplevel.transform(compressor);
+```javascript
+var compressor = UglifyJS.Compressor(options);
+var compressed_ast = compressor.compress(toplevel);
+```
 
 The `options` can be missing.  Available options are discussed above in
 “Compressor options”.  Defaults should lead to best compression in most
@@ -439,33 +893,39 @@ the compressor might drop unused variables / unreachable code and this might
 change the number of identifiers or their position).  Optionally, you can
 call a trick that helps after Gzip (counting character frequency in
 non-mangleable words).  Example:
-
-    compressed_ast.figure_out_scope();
-    compressed_ast.compute_char_frequency();
-    compressed_ast.mangle_names();
+```javascript
+compressed_ast.figure_out_scope();
+compressed_ast.compute_char_frequency();
+compressed_ast.mangle_names();
+```
 
 #### Generating output
 
 AST nodes have a `print` method that takes an output stream.  Essentially,
 to generate code you do this:
-
-    var stream = UglifyJS.OutputStream(options);
-    compressed_ast.print(stream);
-    var code = stream.toString(); // this is your minified code
+```javascript
+var stream = UglifyJS.OutputStream(options);
+compressed_ast.print(stream);
+var code = stream.toString(); // this is your minified code
+```
 
 or, for a shortcut you can do:
+```javascript
+var code = compressed_ast.print_to_string(options);
+```
 
-    var code = compressed_ast.print_to_string(options);
-
-As usual, `options` is optional.  The output stream accepts a lot of otions,
+As usual, `options` is optional.  The output stream accepts a lot of options,
 most of them documented above in section “Beautifier options”.  The two
 which we care about here are `source_map` and `comments`.
 
 #### Keeping comments in the output
 
 In order to keep certain comments in the output you need to pass the
-`comments` option.  Pass a RegExp or a function.  If you pass a RegExp, only
-those comments whose body matches the regexp will be kept.  Note that body
+`comments` option.  Pass a RegExp (as string starting and closing with `/`
+or pass a RegExp object), a boolean or a function.  Stringified options
+`all` and `some` can be passed too, where `some` behaves like it's cli
+equivalent `--comments` without passing a value. If you pass a RegExp,
+only those comments whose body matches the RegExp will be kept.  Note that body
 means without the initial `//` or `/*`.  If you pass a function, it will be
 called for every comment in the tree and will receive two arguments: the
 node that the comment is attached to, and the comment token itself.
@@ -493,16 +953,17 @@ to be a `SourceMap` object (which is a thin wrapper on top of the
 [source-map][source-map] library).
 
 Example:
+```javascript
+var source_map = UglifyJS.SourceMap(source_map_options);
+var stream = UglifyJS.OutputStream({
+	...
+	source_map: source_map
+});
+compressed_ast.print(stream);
 
-    var source_map = UglifyJS.SourceMap(source_map_options);
-    var stream = UglifyJS.OutputStream({
-        ...
-        source_map: source_map
-    });
-    compressed_ast.print(stream);
-
-    var code = stream.toString();
-    var map = source_map.toString(); // json output for your source map
+var code = stream.toString();
+var map = source_map.toString(); // json output for your source map
+```
 
 The `source_map_options` (optional) can contain the following properties:
 
@@ -513,6 +974,26 @@ The `source_map_options` (optional) can contain the following properties:
   came from.  It can be simply a string in JSON, or a JSON object containing
   the original source map.
 
-  [acorn]: https://github.com/marijnh/acorn
+  [acorn]: https://github.com/ternjs/acorn
   [source-map]: https://github.com/mozilla/source-map
   [sm-spec]: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit
+  [codegen]: http://lisperator.net/uglifyjs/codegen
+  [compressor]: http://lisperator.net/uglifyjs/compress
+  [parser]: http://lisperator.net/uglifyjs/parser
+
+#### Harmony
+
+If you wish to use the experimental [harmony](https://github.com/mishoo/UglifyJS2/commits/harmony)
+branch to minify ES2015+ (ES6+) code please use the following in your `package.json` file:
+
+```
+"uglify-js": "git+https://github.com/mishoo/UglifyJS2.git#harmony"
+```
+
+or to directly install the experimental harmony version of uglify:
+
+```
+npm install --save-dev uglify-js@github:mishoo/UglifyJS2#harmony
+```
+
+See [#448](https://github.com/mishoo/UglifyJS2/issues/448) for additional details.

appveyor.yml

@@ -0,0 +1,24 @@
+environment:
+  matrix:
+  - nodejs_version: "0.10"
+  - nodejs_version: "0.12"
+  - nodejs_version: "4.0"
+  - nodejs_version: "6.0"
+
+matrix:
+  fast_finish: true
+
+platform:
+  - x86
+  - x64
+
+install:
+  - ps: Install-Product node $env:nodejs_version $env:platform
+  - npm install
+
+test_script:
+  - node --version
+  - npm --version
+  - npm test
+
+build: off

bin/extract-props.js

@@ -0,0 +1,77 @@
+#! /usr/bin/env node
+
+"use strict";
+
+var U2 = require("../tools/node");
+var fs = require("fs");
+var yargs = require("yargs");
+var ARGS = yargs
+    .describe("o", "Output file")
+    .argv;
+var files = ARGS._.slice();
+var output = {
+    vars: {},
+    props: {}
+};
+
+if (ARGS.o) try {
+    output = JSON.parse(fs.readFileSync(ARGS.o, "utf8"));
+} catch(ex) {}
+
+files.forEach(getProps);
+
+if (ARGS.o) {
+    fs.writeFileSync(ARGS.o, JSON.stringify(output, null, 2), "utf8");
+} else {
+    console.log("%s", JSON.stringify(output, null, 2));
+}
+
+function getProps(filename) {
+    var code = fs.readFileSync(filename, "utf8");
+    var ast = U2.parse(code);
+
+    ast.walk(new U2.TreeWalker(function(node){
+        if (node instanceof U2.AST_ObjectKeyVal) {
+            add(node.key);
+        }
+        else if (node instanceof U2.AST_ObjectProperty) {
+            add(node.key.name);
+        }
+        else if (node instanceof U2.AST_Dot) {
+            add(node.property);
+        }
+        else if (node instanceof U2.AST_Sub) {
+            addStrings(node.property);
+        }
+    }));
+
+    function addStrings(node) {
+        var out = {};
+        try {
+            (function walk(node){
+                node.walk(new U2.TreeWalker(function(node){
+                    if (node instanceof U2.AST_Seq) {
+                        walk(node.cdr);
+                        return true;
+                    }
+                    if (node instanceof U2.AST_String) {
+                        add(node.value);
+                        return true;
+                    }
+                    if (node instanceof U2.AST_Conditional) {
+                        walk(node.consequent);
+                        walk(node.alternative);
+                        return true;
+                    }
+                    throw out;
+                }));
+            })(node);
+        } catch(ex) {
+            if (ex !== out) throw ex;
+        }
+    }
+
+    function add(name) {
+        output.props[name] = true;
+    }
+}

bin/uglifyjs

@@ -5,10 +5,12 @@
 
 var UglifyJS = require("../tools/node");
 var sys = require("util");
-var optimist = require("optimist");
+var yargs = require("yargs");
 var fs = require("fs");
+var path = require("path");
 var acorn;
-var ARGS = optimist
+var screw_ie8 = true;
+var ARGS = yargs
     .usage("$0 input1.js [input2.js ...] [options]\n\
 Use a single dash to read input from the standard input.\
 \n\n\
@@ -19,9 +21,17 @@ mangling you need to use `-c` and `-m`.\
 ")
     .describe("source-map", "Specify an output file where to generate source map.")
     .describe("source-map-root", "The path to the original source to be included in the source map.")
+    .describe("source-map-url", "The path to the source map to be added in //# sourceMappingURL.  Defaults to the value passed with --source-map.")
+    .describe("source-map-inline", "Write base64-encoded source map to the end of js output.  Disabled by default")
+    .describe("source-map-include-sources", "Pass this flag if you want to include the content of source files in the source map as sourcesContent property.")
     .describe("in-source-map", "Input source map, useful if you're compressing JS that was generated from some other original code.")
+    .describe("screw-ie8", "Do not support Internet Explorer 6/7/8. This flag is enabled by default.")
+    .describe("support-ie8", "Support non-standard Internet Explorer 6/7/8 javascript.")
+    .describe("expr", "Parse a single expression, rather than a program (for parsing JSON)")
     .describe("p", "Skip prefix for original filenames that appear in source maps. \
-For example -p 3 will drop 3 directories from file names and ensure they are relative paths.")
+For example -p 3 will drop 3 directories from file names and ensure they are relative paths. \
+You can also specify -p relative, which will make UglifyJS figure out itself the relative paths between original sources, \
+the source map and the output file.")
     .describe("o", "Output file (default STDOUT).")
     .describe("b", "Beautify output/specify output options.")
     .describe("m", "Mangle names/pass mangler options.")
@@ -30,25 +40,43 @@ For example -p 3 will drop 3 directories from file names and ensure they are rel
 Pass options like -c hoist_vars=false,if_return=false. \
 Use -c with no argument to use the default compression options.")
     .describe("d", "Global definitions")
+    .describe("e", "Embed everything in a big function, with a configurable parameter/argument list.")
 
     .describe("comments", "Preserve copyright comments in the output. \
 By default this works like Google Closure, keeping JSDoc-style comments that contain \"@license\" or \"@preserve\". \
 You can optionally pass one of the following arguments to this flag:\n\
 - \"all\" to keep all comments\n\
-- a valid JS regexp (needs to start with a slash) to keep only comments that match.\n\
+- a valid JS RegExp like `/foo/`or `/^!/` to keep only matching comments.\n\
 \
 Note that currently not *all* comments can be kept when compression is on, \
 because of dead code removal or cascading statements into sequences.")
 
+    .describe("preamble", "Preamble to prepend to the output.  You can use this to insert a \
+comment, for example for licensing information.  This will not be \
+parsed, but the source map will adjust for its presence.")
+
     .describe("stats", "Display operations run time on STDERR.")
     .describe("acorn", "Use Acorn for parsing.")
-    .describe("spidermonkey", "Assume input fles are SpiderMonkey AST format (as JSON).")
+    .describe("spidermonkey", "Assume input files are SpiderMonkey AST format (as JSON).")
     .describe("self", "Build itself (UglifyJS2) as a library (implies --wrap=UglifyJS --export-all)")
     .describe("wrap", "Embed everything in a big function, making the “exports” and “global” variables available. \
 You need to pass an argument to this option to specify the name that your module will take when included in, say, a browser.")
     .describe("export-all", "Only used when --wrap, this tells UglifyJS to add code to automatically export all globals.")
     .describe("lint", "Display some scope warnings")
     .describe("v", "Verbose")
+    .describe("V", "Print version number and exit.")
+    .describe("noerr", "Don't throw an error for unknown options in -c, -b or -m.")
+    .describe("bare-returns", "Allow return outside of functions.  Useful when minifying CommonJS modules.")
+    .describe("keep-fnames", "Do not mangle/drop function names.  Useful for code relying on Function.prototype.name.")
+    .describe("quotes", "Quote style (0 - auto, 1 - single, 2 - double, 3 - original)")
+    .describe("reserved-file", "File containing reserved names")
+    .describe("reserve-domprops", "Make (most?) DOM properties reserved for --mangle-props")
+    .describe("mangle-props", "Mangle property names (0 - disabled, 1 - mangle all properties, 2 - mangle unquoted properies)")
+    .describe("mangle-regex", "Only mangle property names matching the regex")
+    .describe("name-cache", "File to hold mangled names mappings")
+    .describe("pure-funcs", "List of functions that can be safely removed if their return value is not used")
+    .describe("dump-spidermonkey-ast", "Dump SpiderMonkey AST to stdout.")
+    .describe("wrap-iife", "Wrap IIFEs in parenthesis. Note: this disables the negate_iife compression option")
 
     .alias("p", "prefix")
     .alias("o", "output")
@@ -58,22 +86,54 @@ You need to pass an argument to this option to specify the name that your module
     .alias("c", "compress")
     .alias("d", "define")
     .alias("r", "reserved")
+    .alias("V", "version")
+    .alias("e", "enclose")
+    .alias("q", "quotes")
 
     .string("source-map")
     .string("source-map-root")
+    .string("source-map-url")
     .string("b")
+    .string("beautify")
     .string("m")
+    .string("mangle")
+    .string("mangle-props-debug")
     .string("c")
+    .string("compress")
     .string("d")
+    .string("define")
+    .string("e")
+    .string("enclose")
     .string("comments")
     .string("wrap")
+    .string("p")
+    .string("prefix")
+    .string("name-cache")
+
+    .array("reserved-file")
+    .array("pure-funcs")
+
+    .boolean("expr")
+    .boolean("source-map-inline")
+    .boolean("source-map-include-sources")
+    .boolean("screw-ie8")
+    .boolean("support-ie8")
     .boolean("export-all")
     .boolean("self")
     .boolean("v")
+    .boolean("verbose")
     .boolean("stats")
     .boolean("acorn")
     .boolean("spidermonkey")
+    .boolean("dump-spidermonkey-ast")
     .boolean("lint")
+    .boolean("V")
+    .boolean("version")
+    .boolean("noerr")
+    .boolean("bare-returns")
+    .boolean("keep-fnames")
+    .boolean("reserve-domprops")
+    .boolean("wrap-iife")
 
     .wrap(80)
 
@@ -82,14 +142,26 @@ You need to pass an argument to this option to specify the name that your module
 
 normalize(ARGS);
 
+if (ARGS.noerr) {
+    UglifyJS.DefaultsError.croak = function(msg, defs) {
+        print_error("WARN: " + msg);
+    };
+}
+
+if (ARGS.version || ARGS.V) {
+    var json = require("../package.json");
+    print(json.name + ' ' + json.version);
+    process.exit(0);
+}
+
 if (ARGS.ast_help) {
     var desc = UglifyJS.describe_ast();
-    sys.puts(typeof desc == "string" ? desc : JSON.stringify(desc, null, 2));
+    print(typeof desc == "string" ? desc : JSON.stringify(desc, null, 2));
     process.exit(0);
 }
 
 if (ARGS.h || ARGS.help) {
-    sys.puts(optimist.help());
+    print(yargs.help());
     process.exit(0);
 }
 
@@ -100,193 +172,374 @@ if (ARGS.acorn) {
 var COMPRESS = getOptions("c", true);
 var MANGLE = getOptions("m", true);
 var BEAUTIFY = getOptions("b", true);
+var RESERVED = null;
 
-if (COMPRESS && ARGS.d) {
-    COMPRESS.global_defs = getOptions("d");
+if (ARGS.reserved_file) ARGS.reserved_file.forEach(function(filename){
+    RESERVED = UglifyJS.readReservedFile(filename, RESERVED);
+});
+
+if (ARGS.reserve_domprops) {
+    RESERVED = UglifyJS.readDefaultReservedFile(RESERVED);
 }
 
-if (MANGLE && ARGS.r) {
-    MANGLE.except = ARGS.r.replace(/^\s+|\s+$/g).split(/\s*,+\s*/);
+if (ARGS.d) {
+    if (COMPRESS) COMPRESS.global_defs = getOptions("d");
+}
+
+if (ARGS.pure_funcs) {
+    if (COMPRESS) COMPRESS.pure_funcs = ARGS.pure_funcs;
+}
+
+if (ARGS.r) {
+    if (MANGLE) MANGLE.except = ARGS.r.replace(/^\s+|\s+$/g).split(/\s*,+\s*/);
+}
+
+if (RESERVED && MANGLE) {
+    if (!MANGLE.except) MANGLE.except = RESERVED.vars;
+    else MANGLE.except = MANGLE.except.concat(RESERVED.vars);
+}
+
+function readNameCache(key) {
+    return UglifyJS.readNameCache(ARGS.name_cache, key);
+}
+
+function writeNameCache(key, cache) {
+    return UglifyJS.writeNameCache(ARGS.name_cache, key, cache);
+}
+
+function extractRegex(str) {
+  if (/^\/.*\/[a-zA-Z]*$/.test(str)) {
+    var regex_pos = str.lastIndexOf("/");
+    return new RegExp(str.substr(1, regex_pos - 1), str.substr(regex_pos + 1));
+  } else {
+    throw new Error("Invalid regular expression: " + str);
+  }
+}
+
+if (ARGS.quotes === true) {
+    ARGS.quotes = 3;
+}
+
+if (ARGS.mangle_props === true) {
+    ARGS.mangle_props = 1;
+} else if (ARGS.mangle_props === "unquoted") {
+    ARGS.mangle_props = 2;
 }
 
 var OUTPUT_OPTIONS = {
-    beautify: BEAUTIFY ? true : false
+    beautify     : BEAUTIFY ? true : false,
+    max_line_len : 32000,
+    preamble     : ARGS.preamble || null,
+    quote_style  : ARGS.quotes != null ? ARGS.quotes : 0,
 };
 
+if (ARGS.mangle_props == 2) {
+    OUTPUT_OPTIONS.keep_quoted_props = true;
+    if (COMPRESS && !("properties" in COMPRESS))
+        COMPRESS.properties = false;
+}
+
+if (ARGS.support_ie8 === true && ARGS.screw_ie8 !== true) {
+    screw_ie8 = false;
+}
+
+if (COMPRESS) COMPRESS.screw_ie8 = screw_ie8;
+if (MANGLE) MANGLE.screw_ie8 = screw_ie8;
+OUTPUT_OPTIONS.screw_ie8 = screw_ie8;
+
+if (ARGS.keep_fnames) {
+    if (COMPRESS) COMPRESS.keep_fnames = true;
+    if (MANGLE) MANGLE.keep_fnames = true;
+}
+
+if (ARGS.wrap_iife) {
+    if (COMPRESS) COMPRESS.negate_iife = false;
+    OUTPUT_OPTIONS.wrap_iife = true;
+}
+
 if (BEAUTIFY)
     UglifyJS.merge(OUTPUT_OPTIONS, BEAUTIFY);
 
-if (ARGS.comments) {
-    if (/^\//.test(ARGS.comments)) {
-        OUTPUT_OPTIONS.comments = new Function("return(" + ARGS.comments + ")")();
-    } else if (ARGS.comments == "all") {
-        OUTPUT_OPTIONS.comments = true;
-    } else {
-        OUTPUT_OPTIONS.comments = function(node, comment) {
-            var text = comment.value;
-            var type = comment.type;
-            if (type == "comment2") {
-                // multiline comment
-                return /@preserve|@license|@cc_on/i.test(text);
-            }
-        }
-    }
+if (ARGS.comments === "") {
+    OUTPUT_OPTIONS.comments = "some";
+} else {
+    OUTPUT_OPTIONS.comments = ARGS.comments;
 }
 
 var files = ARGS._.slice();
 
+if (process.platform === "win32")
+    files = UglifyJS.simple_glob(files);
+
 if (ARGS.self) {
     if (files.length > 0) {
-        sys.error("WARN: Ignoring input files since --self was passed");
+        print_error("WARN: Ignoring input files since --self was passed");
     }
     files = UglifyJS.FILES;
     if (!ARGS.wrap) ARGS.wrap = "UglifyJS";
-    ARGS.export_all = true;
 }
 
 var ORIG_MAP = ARGS.in_source_map;
 
-if (ORIG_MAP) {
+if (ORIG_MAP && ORIG_MAP != "inline") {
     ORIG_MAP = JSON.parse(fs.readFileSync(ORIG_MAP));
     if (files.length == 0) {
-        sys.error("INFO: Using file from the input source map: " + ORIG_MAP.file);
+        print_error("INFO: Using file from the input source map: " + ORIG_MAP.file);
         files = [ ORIG_MAP.file ];
     }
-    if (ARGS.source_map_root == null) {
-        ARGS.source_map_root = ORIG_MAP.sourceRoot;
-    }
 }
 
 if (files.length == 0) {
     files = [ "-" ];
 }
 
-if (files.indexOf("-") >= 0 && ARGS.source_map) {
-    sys.error("ERROR: Source map doesn't work with input from STDIN");
-    process.exit(1);
-}
-
-if (files.filter(function(el){ return el == "-" }).length > 1) {
-    sys.error("ERROR: Can read a single file from STDIN (two or more dashes specified)");
-    process.exit(1);
-}
-
-var STATS = {};
-var OUTPUT_FILE = ARGS.o;
-var TOPLEVEL = null;
-
-var SOURCE_MAP = ARGS.source_map ? UglifyJS.SourceMap({
-    file: OUTPUT_FILE,
-    root: ARGS.source_map_root,
-    orig: ORIG_MAP,
-}) : null;
-
-OUTPUT_OPTIONS.source_map = SOURCE_MAP;
-
-try {
-    var output = UglifyJS.OutputStream(OUTPUT_OPTIONS);
-    var compressor = COMPRESS && UglifyJS.Compressor(COMPRESS);
-} catch(ex) {
-    if (ex instanceof UglifyJS.DefaultsError) {
-        sys.error(ex.msg);
-        sys.error("Supported options:");
-        sys.error(sys.inspect(ex.defs));
+if (ORIG_MAP == "inline") {
+    if (files.length > 1) {
+        print_error("ERROR: Inline source map only works with singular input");
+        process.exit(1);
+    }
+    if (ARGS.acorn || ARGS.spidermonkey) {
+        print_error("ERROR: Inline source map only works with built-in parser");
         process.exit(1);
     }
 }
 
-files.forEach(function(file) {
-    var code = read_whole_file(file);
-    if (ARGS.p != null) {
-        file = file.replace(/^\/+/, "").split(/\/+/).slice(ARGS.p).join("/");
+if (files.indexOf("-") >= 0 && ARGS.source_map) {
+    print_error("ERROR: Source map doesn't work with input from STDIN");
+    process.exit(1);
+}
+
+if (files.filter(function(el){ return el == "-" }).length > 1) {
+    print_error("ERROR: Can read a single file from STDIN (two or more dashes specified)");
+    process.exit(1);
+}
+
+var STATS = {};
+var TOPLEVEL = null;
+var P_RELATIVE = ARGS.p && ARGS.p == "relative";
+var SOURCES_CONTENT = {};
+var index = 0;
+
+!function cb() {
+    if (index == files.length) return done();
+    var file = files[index++];
+    read_whole_file(file, function (err, code) {
+        if (err) {
+            print_error("ERROR: can't read file: " + file);
+            process.exit(1);
+        }
+        if (ORIG_MAP == "inline") {
+            ORIG_MAP = read_source_map(code);
+        }
+        if (ARGS.p != null) {
+            if (P_RELATIVE) {
+                file = path.relative(path.dirname(ARGS.source_map), file).replace(/\\/g, '/');
+            } else {
+                var p = parseInt(ARGS.p, 10);
+                if (!isNaN(p)) {
+                    file = file.replace(/^\/+/, "").split(/\/+/).slice(ARGS.p).join("/");
+                }
+            }
+        }
+        SOURCES_CONTENT[file] = code;
+        time_it("parse", function(){
+            if (ARGS.spidermonkey) {
+                var program = JSON.parse(code);
+                if (!TOPLEVEL) TOPLEVEL = program;
+                else TOPLEVEL.body = TOPLEVEL.body.concat(program.body);
+            }
+            else if (ARGS.acorn) {
+                TOPLEVEL = acorn.parse(code, {
+                    locations     : true,
+                    sourceFile    : file,
+                    program       : TOPLEVEL
+                });
+            }
+            else {
+                try {
+                    TOPLEVEL = UglifyJS.parse(code, {
+                        filename     : file,
+                        toplevel     : TOPLEVEL,
+                        expression   : ARGS.expr,
+                        bare_returns : ARGS.bare_returns,
+                    });
+                } catch(ex) {
+                    if (ex instanceof UglifyJS.JS_Parse_Error) {
+                        print_error("Parse error at " + file + ":" + ex.line + "," + ex.col);
+                        var col = ex.col;
+                        var line = code.split(/\r?\n/)[ex.line - (col ? 1 : 2)];
+                        if (line) {
+                            if (col > 40) {
+                                line = line.slice(col - 40);
+                                col = 40;
+                            }
+                            if (col) {
+                                print_error(line.slice(0, 80));
+                                print_error(line.slice(0, col).replace(/\S/g, " ") + "^");
+                            } else {
+                                print_error(line.slice(-40));
+                                print_error(line.slice(-40).replace(/\S/g, " ") + "^");
+                            }
+                        }
+                        print_error(ex.stack);
+                        process.exit(1);
+                    }
+                    throw ex;
+                }
+            };
+        });
+        cb();
+    });
+}();
+
+function done() {
+    var OUTPUT_FILE = ARGS.o;
+
+    var SOURCE_MAP = (ARGS.source_map || ARGS.source_map_inline) ? UglifyJS.SourceMap({
+        file: P_RELATIVE ? path.relative(path.dirname(ARGS.source_map), OUTPUT_FILE) : OUTPUT_FILE,
+        root: ARGS.source_map_root || ORIG_MAP && ORIG_MAP.sourceRoot,
+        orig: ORIG_MAP,
+    }) : null;
+
+    OUTPUT_OPTIONS.source_map = SOURCE_MAP;
+
+    try {
+        var output = UglifyJS.OutputStream(OUTPUT_OPTIONS);
+        var compressor = COMPRESS && UglifyJS.Compressor(COMPRESS);
+    } catch(ex) {
+        if (ex instanceof UglifyJS.DefaultsError) {
+            print_error(ex.message);
+            print_error("Supported options:");
+            print_error(sys.inspect(ex.defs));
+            process.exit(1);
+        }
     }
-    time_it("parse", function(){
-        if (ARGS.spidermonkey) {
-            var program = JSON.parse(code);
-            if (!TOPLEVEL) TOPLEVEL = program;
-            else TOPLEVEL.body = TOPLEVEL.body.concat(program.body);
-        }
-        else if (ARGS.acorn) {
-            TOPLEVEL = acorn.parse(code, {
-                locations     : true,
-                trackComments : true,
-                sourceFile    : file,
-                program       : TOPLEVEL
-            });
-        }
-        else {
-            TOPLEVEL = UglifyJS.parse(code, {
-                filename: file,
-                toplevel: TOPLEVEL
-            });
-        };
+
+    if (ARGS.acorn || ARGS.spidermonkey) time_it("convert_ast", function(){
+        TOPLEVEL = UglifyJS.AST_Node.from_mozilla_ast(TOPLEVEL);
     });
-});
 
-if (ARGS.acorn || ARGS.spidermonkey) time_it("convert_ast", function(){
-    TOPLEVEL = UglifyJS.AST_Node.from_mozilla_ast(TOPLEVEL);
-});
+    if (ARGS.wrap != null) {
+        TOPLEVEL = TOPLEVEL.wrap_commonjs(ARGS.wrap, ARGS.export_all);
+    }
 
-if (ARGS.wrap) {
-    TOPLEVEL = TOPLEVEL.wrap_commonjs(ARGS.wrap, ARGS.export_all);
-}
-
-var SCOPE_IS_NEEDED = COMPRESS || MANGLE || ARGS.lint;
-
-if (SCOPE_IS_NEEDED) {
-    time_it("scope", function(){
-        TOPLEVEL.figure_out_scope();
-        if (ARGS.lint) {
-            TOPLEVEL.scope_warnings();
+    if (ARGS.enclose != null) {
+        var arg_parameter_list = ARGS.enclose;
+        if (arg_parameter_list === true) {
+            arg_parameter_list = [];
         }
-    });
-}
-
-if (COMPRESS) {
-    time_it("squeeze", function(){
-        TOPLEVEL = TOPLEVEL.transform(compressor);
-    });
-}
-
-if (SCOPE_IS_NEEDED) {
-    time_it("scope", function(){
-        TOPLEVEL.figure_out_scope();
-        if (MANGLE) {
-            TOPLEVEL.compute_char_frequency(MANGLE);
+        else if (!(arg_parameter_list instanceof Array)) {
+            arg_parameter_list = [arg_parameter_list];
         }
+        TOPLEVEL = TOPLEVEL.wrap_enclose(arg_parameter_list);
+    }
+
+    if (ARGS.mangle_props || ARGS.name_cache) (function(){
+        var reserved = RESERVED ? RESERVED.props : null;
+        var cache = readNameCache("props");
+        var regex;
+
+        try {
+          regex = ARGS.mangle_regex ? extractRegex(ARGS.mangle_regex) : null;
+        } catch (e) {
+            print_error("ERROR: Invalid --mangle-regex: " + e.message);
+            process.exit(1);
+        }
+
+        TOPLEVEL = UglifyJS.mangle_properties(TOPLEVEL, {
+            reserved      : reserved,
+            cache         : cache,
+            only_cache    : !ARGS.mangle_props,
+            regex         : regex,
+            ignore_quoted : ARGS.mangle_props == 2,
+            debug         : typeof ARGS.mangle_props_debug === "undefined" ? false : ARGS.mangle_props_debug
+        });
+        writeNameCache("props", cache);
+    })();
+
+    var SCOPE_IS_NEEDED = COMPRESS || MANGLE || ARGS.lint
+    var TL_CACHE = readNameCache("vars");
+    if (MANGLE) MANGLE.cache = TL_CACHE;
+
+    if (SCOPE_IS_NEEDED) {
+        time_it("scope", function(){
+            TOPLEVEL.figure_out_scope(MANGLE || { screw_ie8: screw_ie8, cache: TL_CACHE });
+            if (ARGS.lint) {
+                TOPLEVEL.scope_warnings();
+            }
+        });
+    }
+
+    if (COMPRESS) {
+        time_it("squeeze", function(){
+            TOPLEVEL = compressor.compress(TOPLEVEL);
+        });
+    }
+
+    if (SCOPE_IS_NEEDED) {
+        time_it("scope", function(){
+            TOPLEVEL.figure_out_scope(MANGLE || { screw_ie8: screw_ie8, cache: TL_CACHE });
+            if (MANGLE && !TL_CACHE) {
+                TOPLEVEL.compute_char_frequency(MANGLE);
+            }
+        });
+    }
+
+    if (MANGLE) time_it("mangle", function(){
+        TOPLEVEL.mangle_names(MANGLE);
     });
-}
 
-if (MANGLE) time_it("mangle", function(){
-    TOPLEVEL.mangle_names(MANGLE);
-});
-time_it("generate", function(){
-    TOPLEVEL.print(output);
-});
+    writeNameCache("vars", TL_CACHE);
 
-output = output.get();
+    if (ARGS.source_map_include_sources) {
+        for (var file in SOURCES_CONTENT) {
+            if (SOURCES_CONTENT.hasOwnProperty(file)) {
+                SOURCE_MAP.get().setSourceContent(file, SOURCES_CONTENT[file]);
+            }
+        }
+    }
 
-if (SOURCE_MAP) {
-    fs.writeFileSync(ARGS.source_map, SOURCE_MAP, "utf8");
-    output += "\n//@ sourceMappingURL=" + ARGS.source_map;
-}
+    if (ARGS.dump_spidermonkey_ast) {
+        print(JSON.stringify(TOPLEVEL.to_mozilla_ast(), null, 2));
+    } else {
+        time_it("generate", function(){
+            TOPLEVEL.print(output);
+        });
 
-if (OUTPUT_FILE) {
-    fs.writeFileSync(OUTPUT_FILE, output, "utf8");
-} else {
-    sys.print(output);
-    sys.error("\n");
-}
+        output = output.get();
 
-if (ARGS.stats) {
-    sys.error(UglifyJS.string_template("Timing information (compressed {count} files):", {
-        count: files.length
-    }));
-    for (var i in STATS) if (STATS.hasOwnProperty(i)) {
-        sys.error(UglifyJS.string_template("- {name}: {time}s", {
-            name: i,
-            time: (STATS[i] / 1000).toFixed(3)
+        if (SOURCE_MAP) {
+            if (ARGS.source_map_inline) {
+                var base64_string = new Buffer(SOURCE_MAP.toString()).toString('base64');
+                output += "\n//# sourceMappingURL=data:application/json;charset=utf-8;base64," + base64_string;
+            } else {
+                fs.writeFileSync(ARGS.source_map, SOURCE_MAP, "utf8");
+                var source_map_url = ARGS.source_map_url || (
+                    P_RELATIVE
+                        ? path.relative(path.dirname(OUTPUT_FILE), ARGS.source_map)
+                        : ARGS.source_map
+                );
+                output += "\n//# sourceMappingURL=" + source_map_url;
+            }
+        }
+
+        if (OUTPUT_FILE) {
+            fs.writeFileSync(OUTPUT_FILE, output, "utf8");
+        } else {
+            print(output);
+        }
+    }
+
+    if (ARGS.stats) {
+        print_error(UglifyJS.string_template("Timing information (compressed {count} files):", {
+            count: files.length
         }));
+        for (var i in STATS) if (STATS.hasOwnProperty(i)) {
+            print_error(UglifyJS.string_template("- {name}: {time}s", {
+                name: i,
+                time: (STATS[i] / 1000).toFixed(3)
+            }));
+        }
     }
 }
 
@@ -299,52 +552,67 @@ function normalize(o) {
     }
 }
 
-function getOptions(x, constants) {
-    x = ARGS[x];
-    if (!x) return null;
+function getOptions(flag, constants) {
+    var x = ARGS[flag];
+    if (x == null || x === false) return null;
     var ret = {};
-    if (x !== true) {
+    if (x !== "") {
+        if (Array.isArray(x)) x = x.map(function (v) { return "(" + v + ")"; }).join(", ");
+
         var ast;
         try {
-            ast = UglifyJS.parse(x);
+            ast = UglifyJS.parse(x, { cli: true, expression: true });
         } catch(ex) {
             if (ex instanceof UglifyJS.JS_Parse_Error) {
-                sys.error("Error parsing arguments in: " + x);
+                print_error("Error parsing arguments for flag `" + flag + "': " + x);
                 process.exit(1);
             }
         }
         ast.walk(new UglifyJS.TreeWalker(function(node){
-            if (node instanceof UglifyJS.AST_Toplevel) return; // descend
-            if (node instanceof UglifyJS.AST_SimpleStatement) return; // descend
             if (node instanceof UglifyJS.AST_Seq) return; // descend
             if (node instanceof UglifyJS.AST_Assign) {
-                var name = node.left.print_to_string({ beautify: false }).replace(/-/g, "_");
+                var name = node.left.print_to_string().replace(/-/g, "_");
                 var value = node.right;
                 if (constants)
                     value = new Function("return (" + value.print_to_string() + ")")();
                 ret[name] = value;
                 return true;    // no descend
             }
-            sys.error(node.TYPE)
-            sys.error("Error parsing arguments in: " + x);
+            if (node instanceof UglifyJS.AST_Symbol || node instanceof UglifyJS.AST_Binary) {
+                var name = node.print_to_string().replace(/-/g, "_");
+                ret[name] = true;
+                return true;    // no descend
+            }
+            print_error(node.TYPE)
+            print_error("Error parsing arguments for flag `" + flag + "': " + x);
             process.exit(1);
         }));
     }
     return ret;
 }
 
-function read_whole_file(filename) {
+function read_whole_file(filename, cb) {
     if (filename == "-") {
-        // XXX: this sucks.  How does one read the whole STDIN
-        // synchronously?
-        filename = "/dev/stdin";
+        var chunks = [];
+        process.stdin.setEncoding('utf-8');
+        process.stdin.on('data', function (chunk) {
+            chunks.push(chunk);
+        }).on('end', function () {
+            cb(null, chunks.join(""));
+        });
+        process.openStdin();
+    } else {
+        fs.readFile(filename, "utf-8", cb);
     }
-    try {
-        return fs.readFileSync(filename, "utf8");
-    } catch(ex) {
-        sys.error("ERROR: can't read file: " + filename);
-        process.exit(1);
+}
+
+function read_source_map(code) {
+    var match = /\n\/\/# sourceMappingURL=data:application\/json(;.*?)?;base64,(.*)/.exec(code);
+    if (!match) {
+        print_error("WARN: inline source map not found");
+        return null;
     }
+    return JSON.parse(new Buffer(match[2], "base64"));
 }
 
 function time_it(name, cont) {
@@ -357,3 +625,11 @@ function time_it(name, cont) {
     }
     return ret;
 }
+
+function print_error(msg) {
+    console.error("%s", msg);
+}
+
+function print(txt) {
+    console.log("%s", txt);
+}

lib/ast.js

@@ -71,7 +71,7 @@ function DEFNODE(type, props, methods, base) {
     if (type) {
         ctor.prototype.TYPE = ctor.TYPE = type;
     }
-    if (methods) for (i in methods) if (methods.hasOwnProperty(i)) {
+    if (methods) for (i in methods) if (HOP(methods, i)) {
         if (/^\$/.test(i)) {
             ctor[i.substr(1)] = methods[i];
         } else {
@@ -81,16 +81,30 @@ function DEFNODE(type, props, methods, base) {
     ctor.DEFMETHOD = function(name, method) {
         this.prototype[name] = method;
     };
+    if (typeof exports !== "undefined") {
+        exports["AST_" + type] = ctor;
+    }
     return ctor;
 };
 
-var AST_Token = DEFNODE("Token", "type value line col pos endpos nlb comments_before file", {
+var AST_Token = DEFNODE("Token", "type value line col pos endline endcol endpos nlb comments_before file raw", {
 }, null);
 
 var AST_Node = DEFNODE("Node", "start end", {
-    clone: function() {
+    _clone: function(deep) {
+        if (deep) {
+            var self = this.clone();
+            return self.transform(new TreeTransformer(function(node) {
+                if (node !== self) {
+                    return node.clone(true);
+                }
+            }));
+        }
         return new this.CTOR(this);
     },
+    clone: function(deep) {
+        return this._clone(deep);
+    },
     $documentation: "Base class of all AST nodes",
     $propdoc: {
         start: "[AST_Token] The first token of this node",
@@ -120,11 +134,12 @@ var AST_Debugger = DEFNODE("Debugger", null, {
     $documentation: "Represents a debugger statement",
 }, AST_Statement);
 
-var AST_Directive = DEFNODE("Directive", "value scope", {
+var AST_Directive = DEFNODE("Directive", "value scope quote", {
     $documentation: "Represents a directive, like \"use strict\";",
     $propdoc: {
         value: "[string] The value of this directive as a plain string (it's not an AST_String!)",
-        scope: "[AST_Scope/S] The scope that this directive affects"
+        scope: "[AST_Scope/S] The scope that this directive affects",
+        quote: "[string] the original quote character"
     },
 }, AST_Statement);
 
@@ -141,12 +156,13 @@ var AST_SimpleStatement = DEFNODE("SimpleStatement", "body", {
 }, AST_Statement);
 
 function walk_body(node, visitor) {
-    if (node.body instanceof AST_Statement) {
-        node.body._walk(visitor);
+    var body = node.body;
+    if (body instanceof AST_Node) {
+        body._walk(visitor);
+    }
+    else for (var i = 0, len = body.length; i < len; i++) {
+        body[i]._walk(visitor);
     }
-    else node.body.forEach(function(stat){
-        stat._walk(visitor);
-    });
 };
 
 var AST_Block = DEFNODE("Block", "body", {
@@ -194,28 +210,52 @@ var AST_LabeledStatement = DEFNODE("LabeledStatement", "label", {
             this.label._walk(visitor);
             this.body._walk(visitor);
         });
+    },
+    clone: function(deep) {
+        var node = this._clone(deep);
+        if (deep) {
+            var refs = node.label.references;
+            var label = this.label;
+            node.walk(new TreeWalker(function(node) {
+                if (node instanceof AST_LoopControl
+                    && node.label && node.label.thedef === label) {
+                    refs.push(node);
+                }
+            }));
+        }
+        return node;
     }
 }, AST_StatementWithBody);
 
+var AST_IterationStatement = DEFNODE("IterationStatement", null, {
+    $documentation: "Internal class.  All loops inherit from it."
+}, AST_StatementWithBody);
+
 var AST_DWLoop = DEFNODE("DWLoop", "condition", {
     $documentation: "Base class for do/while statements",
     $propdoc: {
         condition: "[AST_Node] the loop condition.  Should not be instanceof AST_Statement"
-    },
+    }
+}, AST_IterationStatement);
+
+var AST_Do = DEFNODE("Do", null, {
+    $documentation: "A `do` statement",
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.body._walk(visitor);
+            this.condition._walk(visitor);
+        });
+    }
+}, AST_DWLoop);
+
+var AST_While = DEFNODE("While", null, {
+    $documentation: "A `while` statement",
     _walk: function(visitor) {
         return visitor._visit(this, function(){
             this.condition._walk(visitor);
             this.body._walk(visitor);
         });
     }
-}, AST_StatementWithBody);
-
-var AST_Do = DEFNODE("Do", null, {
-    $documentation: "A `do` statement",
-}, AST_DWLoop);
-
-var AST_While = DEFNODE("While", null, {
-    $documentation: "A `while` statement",
 }, AST_DWLoop);
 
 var AST_For = DEFNODE("For", "init condition step", {
@@ -233,7 +273,7 @@ var AST_For = DEFNODE("For", "init condition step", {
             this.body._walk(visitor);
         });
     }
-}, AST_StatementWithBody);
+}, AST_IterationStatement);
 
 var AST_ForIn = DEFNODE("ForIn", "init name object", {
     $documentation: "A `for ... in` statement",
@@ -249,7 +289,11 @@ var AST_ForIn = DEFNODE("ForIn", "init name object", {
             this.body._walk(visitor);
         });
     }
-}, AST_StatementWithBody);
+}, AST_IterationStatement);
+
+var AST_ForOf = DEFNODE("ForOf", null, {
+    $documentation: "A `for ... of` statement",
+}, AST_ForIn);
 
 var AST_With = DEFNODE("With", "expression", {
     $documentation: "A `with` statement",
@@ -278,6 +322,13 @@ var AST_Scope = DEFNODE("Scope", "directives variables functions uses_with uses_
         enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
         cname: "[integer/S] current index for mangling variables (used internally by the mangler)",
     },
+    get_defun_scope: function () {
+        var self = this;
+        while (self.is_block_scope() && self.parent_scope) {
+            self = self.parent_scope;
+        }
+        return self;
+    }
 }, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
@@ -285,11 +336,32 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     $propdoc: {
         globals: "[Object/S] a map of name -> SymbolDef for all undeclared names",
     },
+    wrap_enclose: function(arg_parameter_pairs) {
+        var self = this;
+        var args = [];
+        var parameters = [];
+
+        arg_parameter_pairs.forEach(function(pair) {
+            var splitAt = pair.lastIndexOf(":");
+
+            args.push(pair.substr(0, splitAt));
+            parameters.push(pair.substr(splitAt + 1));
+        });
+
+        var wrapped_tl = "(function(" + parameters.join(",") + "){ '$ORIG'; })(" + args.join(",") + ")";
+        wrapped_tl = parse(wrapped_tl);
+        wrapped_tl = wrapped_tl.transform(new TreeTransformer(function before(node){
+            if (node instanceof AST_Directive && node.value == "$ORIG") {
+                return MAP.splice(self.body);
+            }
+        }));
+        return wrapped_tl;
+    },
     wrap_commonjs: function(name, export_all) {
         var self = this;
+        var to_export = [];
         if (export_all) {
             self.figure_out_scope();
-            var to_export = [];
             self.walk(new TreeWalker(function(node){
                 if (node instanceof AST_SymbolDeclaration && node.definition().global) {
                     if (!find_if(function(n){ return n.name == node.name }, to_export))
@@ -297,12 +369,11 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
                 }
             }));
         }
-        var wrapped_tl = "(function(exports, global){ global['" + name + "'] = exports; '$ORIG'; '$EXPORTS'; }({}, (function(){return this}())))";
+        var wrapped_tl = "(function(exports, global){ '$ORIG'; '$EXPORTS'; global['" + name + "'] = exports; }({}, (function(){return this}())))";
         wrapped_tl = parse(wrapped_tl);
         wrapped_tl = wrapped_tl.transform(new TreeTransformer(function before(node){
-            if (node instanceof AST_SimpleStatement) {
-                node = node.body;
-                if (node instanceof AST_String) switch (node.getValue()) {
+            if (node instanceof AST_Directive) {
+                switch (node.value) {
                   case "$ORIG":
                     return MAP.splice(self.body);
                   case "$EXPORTS":
@@ -327,36 +398,199 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     }
 }, AST_Scope);
 
-var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments", {
+var AST_Expansion = DEFNODE("Expansion", "expression", {
+    $documentation: "An expandible argument, such as ...rest, a splat, such as [1,2,...all], or an expansion in a variable declaration, such as var [first, ...rest] = list",
+    $propdoc: {
+        expression: "AST_Symbol the thing to be expanded"
+    },
+    _walk: function(visitor) {
+        var self = this;
+        return visitor._visit(this, function(){
+            self.expression.walk(visitor);
+        });
+    }
+});
+
+var AST_ArrowParametersOrSeq = DEFNODE("ArrowParametersOrSeq", "expressions", {
+    $documentation: "A set of arrow function parameters or a sequence expression. This is used because when the parser sees a \"(\" it could be the start of a seq, or the start of a parameter list of an arrow function.",
+    $propdoc: {
+        expressions: "[AST_Expression|AST_Destructuring|AST_Expansion*] array of expressions or argument names or destructurings."
+    },
+    as_params: function (croak) {
+        // We don't want anything which doesn't belong in a destructuring
+        var root = this;
+        return this.expressions.map(function to_fun_args(ex, _, __, default_seen_above) {
+            var insert_default = function(ex, default_value) {
+                if (default_value) {
+                    return new AST_DefaultAssign({
+                        start: ex.start,
+                        left: ex,
+                        operator: "=",
+                        right: default_value,
+                        end: default_value.end
+                    });
+                }
+                return ex;
+            }
+            if (ex instanceof AST_Object) {
+                return insert_default(new AST_Destructuring({
+                    start: ex.start,
+                    end: ex.end,
+                    is_array: false,
+                    names: ex.properties.map(to_fun_args)
+                }), default_seen_above);
+            } else if (ex instanceof AST_ObjectKeyVal) {
+                if (ex.key instanceof AST_SymbolRef) {
+                    ex.key = to_fun_args(ex.key, 0, [ex.key]);
+                }
+                ex.value = to_fun_args(ex.value, 0, [ex.key]);
+                return insert_default(ex, default_seen_above);
+            } else if (ex instanceof AST_Hole) {
+                return ex;
+            } else if (ex instanceof AST_Destructuring) {
+                if (ex.names.length == 0)
+                    croak("Invalid destructuring function parameter", ex.start.line, ex.start.col);
+                ex.names = ex.names.map(to_fun_args);
+                return insert_default(ex, default_seen_above);
+            } else if (ex instanceof AST_SymbolRef) {
+                return insert_default(new AST_SymbolFunarg({
+                    name: ex.name,
+                    start: ex.start,
+                    end: ex.end
+                }), default_seen_above);
+            } else if (ex instanceof AST_Expansion) {
+                ex.expression = to_fun_args(ex.expression);
+                return insert_default(ex, default_seen_above);
+            } else if (ex instanceof AST_Array) {
+                return insert_default(new AST_Destructuring({
+                    start: ex.start,
+                    end: ex.end,
+                    is_array: true,
+                    names: ex.elements.map(to_fun_args)
+                }), default_seen_above);
+            } else if (ex instanceof AST_Assign) {
+                return insert_default(to_fun_args(ex.left, undefined, undefined, ex.right), default_seen_above);
+            } else {
+                croak("Invalid function parameter", ex.start.line, ex.start.col);
+            }
+        });
+    },
+    as_expr: function (croak) {
+        return AST_Seq.from_array(this.expressions);
+    }
+});
+
+var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments is_generator", {
     $documentation: "Base class for functions",
     $propdoc: {
+        is_generator: "[boolean] is generatorFn or not",
         name: "[AST_SymbolDeclaration?] the name of this function",
-        argnames: "[AST_SymbolFunarg*] array of function arguments",
+        argnames: "[AST_SymbolFunarg|AST_Destructuring|AST_Expansion|AST_DefaultAssign*] array of function arguments, destructurings, or expanding arguments",
         uses_arguments: "[boolean/S] tells whether this function accesses the arguments array"
     },
+    args_as_names: function () {
+        var out = [];
+        for (var i = 0; i < this.argnames.length; i++) {
+            if (this.argnames[i] instanceof AST_Destructuring) {
+                out = out.concat(this.argnames[i].all_symbols());
+            } else {
+                out.push(this.argnames[i]);
+            }
+        }
+        return out;
+    },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
             if (this.name) this.name._walk(visitor);
-            this.argnames.forEach(function(arg){
-                arg._walk(visitor);
-            });
+            var argnames = this.argnames;
+            for (var i = 0, len = argnames.length; i < len; i++) {
+                argnames[i]._walk(visitor);
+            }
             walk_body(this, visitor);
         });
     }
 }, AST_Scope);
 
 var AST_Accessor = DEFNODE("Accessor", null, {
-    $documentation: "A setter/getter function"
+    $documentation: "A setter/getter function.  The `name` property is always null."
 }, AST_Lambda);
 
 var AST_Function = DEFNODE("Function", null, {
     $documentation: "A function expression"
 }, AST_Lambda);
 
+var AST_Arrow = DEFNODE("Arrow", null, {
+    $documentation: "An ES6 Arrow function ((a) => b)"
+}, AST_Lambda);
+
 var AST_Defun = DEFNODE("Defun", null, {
     $documentation: "A function definition"
 }, AST_Lambda);
 
+/* -----[ DESTRUCTURING ]----- */
+var AST_Destructuring = DEFNODE("Destructuring", "names is_array", {
+    $documentation: "A destructuring of several names. Used in destructuring assignment and with destructuring function argument names",
+    $propdoc: {
+        "names": "[AST_Node*] Array of properties or elements",
+        "is_array": "[Boolean] Whether the destructuring represents an object or array"
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.names.forEach(function(name){
+                name._walk(visitor);
+            });
+        });
+    },
+    all_symbols: function() {
+        var out = [];
+        this.walk(new TreeWalker(function (node) {
+            if (node instanceof AST_Symbol) {
+                out.push(node);
+            }
+            if (node instanceof AST_Expansion) {
+                out.push(node.expression);
+            }
+        }));
+        return out;
+    }
+});
+
+var AST_PrefixedTemplateString = DEFNODE("PrefixedTemplateString", "template_string prefix", {
+    $documentation: "A templatestring with a prefix, such as String.raw`foobarbaz`",
+    $propdoc: {
+        template_string: "[AST_TemplateString] The template string",
+        prefix: "[AST_SymbolRef|AST_PropAccess] The prefix, which can be a symbol such as `foo` or a dotted expression such as `String.raw`."
+    },
+    _walk: function(visitor) {
+        this.prefix._walk(visitor);
+        this.template_string._walk(visitor);
+    }
+})
+
+var AST_TemplateString = DEFNODE("TemplateString", "segments", {
+    $documentation: "A template string literal",
+    $propdoc: {
+        segments: "[AST_TemplateSegment|AST_Expression]* One or more segments, starting with AST_TemplateSegment. AST_Expression may follow AST_TemplateSegment, but each AST_Expression must be followed by AST_TemplateSegment."
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            this.segments.forEach(function(seg, i){
+                if (i % 2 !== 0) {
+                    seg._walk(visitor);
+                }
+            });
+        });
+    }
+});
+
+var AST_TemplateSegment = DEFNODE("TemplateSegment", "value raw", {
+    $documentation: "A segment of a template string literal",
+    $propdoc: {
+        value: "Content of the segment",
+        raw: "Raw content of the segment"
+    }
+});
+
 /* -----[ JUMPS ]----- */
 
 var AST_Jump = DEFNODE("Jump", null, {
@@ -473,16 +707,10 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
     }
 }, AST_Block);
 
-// XXX: this is wrong according to ECMA-262 (12.4).  the catch block
-// should introduce another scope, as the argname should be visible
-// only inside the catch block.  However, doing it this way because of
-// IE which simply introduces the name in the surrounding scope.  If
-// we ever want to fix this then AST_Catch should inherit from
-// AST_Scope.
 var AST_Catch = DEFNODE("Catch", "argname", {
     $documentation: "A `catch` node; only makes sense as part of a `try` statement",
     $propdoc: {
-        argname: "[AST_SymbolCatch] symbol for the exception"
+        argname: "[AST_SymbolCatch|AST_Destructuring|AST_Expansion|AST_DefaultAssign] symbol for the exception"
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
@@ -505,9 +733,10 @@ var AST_Definitions = DEFNODE("Definitions", "definitions", {
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.definitions.forEach(function(def){
-                def._walk(visitor);
-            });
+            var definitions = this.definitions;
+            for (var i = 0, len = definitions.length; i < len; i++) {
+                definitions[i]._walk(visitor);
+            }
         });
     }
 }, AST_Statement);
@@ -516,14 +745,75 @@ var AST_Var = DEFNODE("Var", null, {
     $documentation: "A `var` statement"
 }, AST_Definitions);
 
+var AST_Let = DEFNODE("Let", null, {
+    $documentation: "A `let` statement"
+}, AST_Definitions);
+
 var AST_Const = DEFNODE("Const", null, {
     $documentation: "A `const` statement"
 }, AST_Definitions);
 
+var AST_NameImport = DEFNODE("NameImport", "foreign_name name", {
+    $documentation: "The part of the import statement that imports names from a module.",
+    $propdoc: {
+        foreign_name: "[AST_SymbolImportForeign] The name being imported (as specified in the module)",
+        name: "[AST_SymbolImport] The name as it becomes available to this module."
+    },
+    _walk: function (visitor) {
+        return visitor._visit(this, function() {
+            this.foreign_name._walk(visitor);
+            this.name._walk(visitor);
+        });
+    }
+})
+
+var AST_Import = DEFNODE("Import", "imported_name imported_names module_name", {
+    $documentation: "An `import` statement",
+    $propdoc: {
+        imported_name: "[AST_SymbolImport] The name of the variable holding the module's default export.",
+        imported_names: "[AST_NameImport*] The names of non-default imported variables",
+        module_name: "[AST_String] String literal describing where this module came from",
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function() {
+            if (this.imported_name) {
+                this.imported_name._walk(visitor);
+            }
+            if (this.imported_names) {
+                this.imported_names.forEach(function (name_import) {
+                    name_import._walk(visitor);
+                });
+            }
+            this.module_name._walk(visitor);
+        });
+    }
+});
+
+var AST_Export = DEFNODE("Export", "exported_definition exported_value is_default exported_names module_name", {
+    $documentation: "An `export` statement",
+    $propdoc: {
+        exported_definition: "[AST_Defun|AST_Definitions|AST_DefClass?] An exported definition",
+        exported_value: "[AST_Node?] An exported value",
+        exported_names: "[AST_NameImport*?] List of exported names",
+        module_name: "[AST_String?] Name of the file to load exports from",
+        is_default: "[Boolean] Whether this is the default exported value of this module"
+    },
+    _walk: function (visitor) {
+        visitor._visit(this, function () {
+            if (this.exported_definition) {
+                this.exported_definition._walk(visitor);
+            }
+            if (this.exported_value) {
+                this.exported_value._walk(visitor);
+            }
+        });
+    }
+}, AST_Statement);
+
 var AST_VarDef = DEFNODE("VarDef", "name value", {
     $documentation: "A variable declaration; only appears in a AST_Definitions node",
     $propdoc: {
-        name: "[AST_SymbolVar|AST_SymbolConst] name of the variable",
+        name: "[AST_SymbolVar|AST_SymbolConst|AST_Destructuring] name of the variable",
         value: "[AST_Node?] initializer, or null of there's no initializer"
     },
     _walk: function(visitor) {
@@ -545,9 +835,10 @@ var AST_Call = DEFNODE("Call", "expression args", {
     _walk: function(visitor) {
         return visitor._visit(this, function(){
             this.expression._walk(visitor);
-            this.args.forEach(function(arg){
-                arg._walk(visitor);
-            });
+            var args = this.args;
+            for (var i = 0, len = args.length; i < len; i++) {
+                args[i]._walk(visitor);
+            }
         });
     }
 });
@@ -607,6 +898,13 @@ var AST_Seq = DEFNODE("Seq", "car cdr", {
             p = p.cdr;
         }
     },
+    len: function() {
+        if (this.cdr instanceof AST_Seq) {
+            return this.cdr.len() + 1;
+        } else {
+            return 2;
+        }
+    },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
             this.car._walk(visitor);
@@ -698,6 +996,10 @@ var AST_Assign = DEFNODE("Assign", null, {
     $documentation: "An assignment expression — `a = b + 5`",
 }, AST_Binary);
 
+var AST_DefaultAssign = DEFNODE("DefaultAssign", null, {
+    $documentation: "A default assignment expression like in `(a = 3) => a`"
+}, AST_Binary);
+
 /* -----[ LITERALS ]----- */
 
 var AST_Array = DEFNODE("Array", "elements", {
@@ -707,9 +1009,10 @@ var AST_Array = DEFNODE("Array", "elements", {
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.elements.forEach(function(el){
-                el._walk(visitor);
-            });
+            var elements = this.elements;
+            for (var i = 0, len = elements.length; i < len; i++) {
+                elements[i]._walk(visitor);
+            }
         });
     }
 });
@@ -721,9 +1024,10 @@ var AST_Object = DEFNODE("Object", "properties", {
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.properties.forEach(function(prop){
-                prop._walk(visitor);
-            });
+            var properties = this.properties;
+            for (var i = 0, len = properties.length; i < len; i++) {
+                properties[i]._walk(visitor);
+            }
         });
     }
 });
@@ -731,35 +1035,91 @@ var AST_Object = DEFNODE("Object", "properties", {
 var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
     $documentation: "Base class for literal object properties",
     $propdoc: {
-        key: "[string] the property name; it's always a plain string in our AST, no matter if it was a string, number or identifier in original code",
-        value: "[AST_Node] property value.  For setters and getters this is an AST_Function."
+        key: "[string|AST_Node] the property name converted to a string for ObjectKeyVal. For setters, getters and computed property this is an arbitrary AST_Node",
+        value: "[AST_Node] property value. For setters and getters this is an AST_Function."
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
+            if (this.key instanceof AST_Node)
+                this.key._walk(visitor);
             this.value._walk(visitor);
         });
     }
 });
 
-var AST_ObjectKeyVal = DEFNODE("ObjectKeyVal", null, {
+var AST_ObjectKeyVal = DEFNODE("ObjectKeyVal", "quote", {
     $documentation: "A key: value object property",
+    $propdoc: {
+        quote: "[string] the original quote character"
+    }
 }, AST_ObjectProperty);
 
-var AST_ObjectSetter = DEFNODE("ObjectSetter", null, {
+var AST_ObjectSetter = DEFNODE("ObjectSetter", "quote static", {
+    $propdoc: {
+        quote: "[string|undefined] the original quote character, if any",
+        static: "[boolean] whether this is a static setter (classes only)"
+    },
     $documentation: "An object setter property",
 }, AST_ObjectProperty);
 
-var AST_ObjectGetter = DEFNODE("ObjectGetter", null, {
+var AST_ObjectGetter = DEFNODE("ObjectGetter", "quote static", {
+    $propdoc: {
+        quote: "[string|undefined] the original quote character, if any",
+        static: "[boolean] whether this is a static getter (classes only)"
+    },
     $documentation: "An object getter property",
 }, AST_ObjectProperty);
 
+var AST_ConciseMethod = DEFNODE("ConciseMethod", "quote static is_generator", {
+    $propdoc: {
+        quote: "[string|undefined] the original quote character, if any",
+        static: "[boolean] whether this method is static (classes only)",
+        is_generator: "[boolean] is generatorFn or not",
+    },
+    $documentation: "An ES6 concise method inside an object or class"
+}, AST_ObjectProperty);
+
+var AST_Class = DEFNODE("Class", "name extends properties", {
+    $propdoc: {
+        name: "[AST_SymbolClass|AST_SymbolDefClass?] optional class name.",
+        extends: "[AST_Node]? optional parent class",
+        properties: "[AST_ObjectProperty*] array of properties"
+    },
+    $documentation: "An ES6 class",
+    _walk: function(visitor) {
+        return visitor._visit(this, function(){
+            if (this.name) {
+                this.name._walk(visitor);
+            }
+            if (this.extends) {
+                this.extends._walk(visitor);
+            }
+            this.properties.forEach(function(prop){
+                prop._walk(visitor);
+            });
+        });
+    },
+}, AST_Scope);
+
+var AST_DefClass = DEFNODE("DefClass", null, {
+    $documentation: "A class definition",
+}, AST_Class);
+
+var AST_ClassExpression = DEFNODE("ClassExpression", null, {
+    $documentation: "A class expression."
+}, AST_Class);
+
 var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
     $propdoc: {
         name: "[string] name of this symbol",
         scope: "[AST_Scope/S] the current scope (not necessarily the definition scope)",
         thedef: "[SymbolDef/S] the definition of this symbol"
     },
-    $documentation: "Base class for all symbols",
+    $documentation: "Base class for all symbols"
+});
+
+var AST_NewTarget = DEFNODE("NewTarget", null, {
+    $documentation: "A reference to new.target"
 });
 
 var AST_SymbolAccessor = DEFNODE("SymbolAccessor", null, {
@@ -768,18 +1128,23 @@ var AST_SymbolAccessor = DEFNODE("SymbolAccessor", null, {
 
 var AST_SymbolDeclaration = DEFNODE("SymbolDeclaration", "init", {
     $documentation: "A declaration symbol (symbol in var/const, function name or argument, symbol in catch)",
-    $propdoc: {
-        init: "[AST_Node*/S] array of initializers for this declaration."
-    }
 }, AST_Symbol);
 
 var AST_SymbolVar = DEFNODE("SymbolVar", null, {
     $documentation: "Symbol defining a variable",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolBlockDeclaration = DEFNODE("SymbolBlockDeclaration", null, {
+    $documentation: "Base class for block-scoped declaration symbols"
+}, AST_SymbolDeclaration);
+
 var AST_SymbolConst = DEFNODE("SymbolConst", null, {
     $documentation: "A constant declaration"
-}, AST_SymbolDeclaration);
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolLet = DEFNODE("SymbolLet", null, {
+    $documentation: "A block-scoped `let` declaration"
+}, AST_SymbolBlockDeclaration);
 
 var AST_SymbolFunarg = DEFNODE("SymbolFunarg", null, {
     $documentation: "Symbol naming a function argument",
@@ -789,18 +1154,42 @@ var AST_SymbolDefun = DEFNODE("SymbolDefun", null, {
     $documentation: "Symbol defining a function",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolMethod = DEFNODE("SymbolMethod", null, {
+    $documentation: "Symbol in an object defining a method",
+}, AST_Symbol);
+
 var AST_SymbolLambda = DEFNODE("SymbolLambda", null, {
     $documentation: "Symbol naming a function expression",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolDefClass = DEFNODE("SymbolDefClass", null, {
+    $documentation: "Symbol naming a class's name in a class declaration. Lexically scoped to its containing scope, and accessible within the class."
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolClass = DEFNODE("SymbolClass", null, {
+    $documentation: "Symbol naming a class's name. Lexically scoped to the class."
+}, AST_SymbolDeclaration);
+
 var AST_SymbolCatch = DEFNODE("SymbolCatch", null, {
     $documentation: "Symbol naming the exception in catch",
-}, AST_SymbolDeclaration);
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolImport = DEFNODE("SymbolImport", null, {
+    $documentation: "Symbol refering to an imported name",
+}, AST_SymbolBlockDeclaration);
+
+var AST_SymbolImportForeign = DEFNODE("SymbolImportForeign", null, {
+    $documentation: "A symbol imported from a module, but it is defined in the other module, and its real name is irrelevant for this module's purposes",
+}, AST_Symbol);
 
 var AST_Label = DEFNODE("Label", "references", {
     $documentation: "Symbol naming a label (declaration)",
     $propdoc: {
-        references: "[AST_LabelRef*] a list of nodes referring to this label"
+        references: "[AST_LoopControl*] a list of nodes referring to this label"
+    },
+    initialize: function() {
+        this.references = [];
+        this.thedef = this;
     }
 }, AST_Symbol);
 
@@ -816,6 +1205,10 @@ var AST_This = DEFNODE("This", null, {
     $documentation: "The `this` symbol",
 }, AST_Symbol);
 
+var AST_Super = DEFNODE("Super", null, {
+    $documentation: "The `super` symbol",
+}, AST_Symbol);
+
 var AST_Constant = DEFNODE("Constant", null, {
     $documentation: "Base class for all constants",
     getValue: function() {
@@ -823,17 +1216,19 @@ var AST_Constant = DEFNODE("Constant", null, {
     }
 });
 
-var AST_String = DEFNODE("String", "value", {
+var AST_String = DEFNODE("String", "value quote", {
     $documentation: "A string literal",
     $propdoc: {
-        value: "[string] the contents of this string"
+        value: "[string] the contents of this string",
+        quote: "[string] the original quote character"
     }
 }, AST_Constant);
 
-var AST_Number = DEFNODE("Number", "value", {
+var AST_Number = DEFNODE("Number", "value literal", {
     $documentation: "A number literal",
     $propdoc: {
-        value: "[number] the numeric value"
+        value: "[number] the numeric value",
+        literal: "[string] numeric value as string (optional)"
     }
 }, AST_Constant);
 
@@ -863,6 +1258,11 @@ var AST_Undefined = DEFNODE("Undefined", null, {
     value: (function(){}())
 }, AST_Atom);
 
+var AST_Hole = DEFNODE("Hole", null, {
+    $documentation: "A hole in an array",
+    value: (function(){}())
+}, AST_Atom);
+
 var AST_Infinity = DEFNODE("Infinity", null, {
     $documentation: "The `Infinity` value",
     value: 1/0
@@ -882,32 +1282,61 @@ var AST_True = DEFNODE("True", null, {
     value: true
 }, AST_Boolean);
 
+/* -----[ Yield ]----- */
+
+var AST_Yield = DEFNODE("Yield", "expression is_star", {
+    $documentation: "A `yield` statement",
+    $propdoc: {
+        expression: "[AST_Node?] the value returned or thrown by this statement; could be null (representing undefined) but only when is_star is set to false",
+        is_star: "[Boolean] Whether this is a yield or yield* statement"
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, this.expression && function(){
+            this.expression._walk(visitor);
+        });
+    }
+});
+
 /* -----[ TreeWalker ]----- */
 
 function TreeWalker(callback) {
     this.visit = callback;
     this.stack = [];
+    this.directives = Object.create(null);
 };
 TreeWalker.prototype = {
     _visit: function(node, descend) {
-        this.stack.push(node);
+        this.push(node);
         var ret = this.visit(node, descend ? function(){
             descend.call(node);
         } : noop);
         if (!ret && descend) {
             descend.call(node);
         }
-        this.stack.pop();
+        this.pop(node);
         return ret;
     },
     parent: function(n) {
         return this.stack[this.stack.length - 2 - (n || 0)];
     },
     push: function (node) {
+        if (node instanceof AST_Lambda) {
+            this.directives = Object.create(this.directives);
+        } else if (node instanceof AST_Directive && !this.directives[node.value]) {
+            this.directives[node.value] = node;
+        } else if (node instanceof AST_Class) {
+            this.directives = Object.create(this.directives);
+            if (!this.directives["use strict"]) {
+                this.directives["use strict"] = node;
+            }
+        }
         this.stack.push(node);
     },
-    pop: function() {
-        return this.stack.pop();
+    pop: function(node) {
+        this.stack.pop();
+        if (node instanceof AST_Lambda || node instanceof AST_Class) {
+            this.directives = Object.getPrototypeOf(this.directives);
+        }
     },
     self: function() {
         return this.stack[this.stack.length - 1];
@@ -919,6 +1348,18 @@ TreeWalker.prototype = {
             if (x instanceof type) return x;
         }
     },
+    has_directive: function(type) {
+        var dir = this.directives[type];
+        if (dir) return dir;
+        var node = this.stack[this.stack.length - 1];
+        if (node instanceof AST_Scope && node.body) {
+            for (var i = 0; i < node.body.length; ++i) {
+                var st = node.body[i];
+                if (!(st instanceof AST_Directive)) break;
+                if (st.value == type) return st;
+            }
+        }
+    },
     in_boolean_context: function() {
         var stack = this.stack;
         var i = stack.length, self = stack[--i];
@@ -939,21 +1380,15 @@ TreeWalker.prototype = {
     },
     loopcontrol_target: function(label) {
         var stack = this.stack;
-        if (label) {
-            for (var i = stack.length; --i >= 0;) {
-                var x = stack[i];
-                if (x instanceof AST_LabeledStatement && x.label.name == label.name) {
-                    return x.body;
-                }
-            }
-        } else {
-            for (var i = stack.length; --i >= 0;) {
-                var x = stack[i];
-                if (x instanceof AST_Switch
-                    || x instanceof AST_For
-                    || x instanceof AST_ForIn
-                    || x instanceof AST_DWLoop) return x;
+        if (label) for (var i = stack.length; --i >= 0;) {
+            var x = stack[i];
+            if (x instanceof AST_LabeledStatement && x.label.name == label.name) {
+                return x.body;
             }
+        } else for (var i = stack.length; --i >= 0;) {
+            var x = stack[i];
+            if (x instanceof AST_Switch || x instanceof AST_IterationStatement)
+                return x;
         }
     }
 };

lib/mozilla-ast.js

@@ -45,54 +45,113 @@
 
 (function(){
 
+    var normalize_directives = function(body) {
+        var in_directive = true;
+
+        for (var i = 0; i < body.length; i++) {
+            if (in_directive && body[i] instanceof AST_Statement && body[i].body instanceof AST_String) {
+                body[i] = new AST_Directive({
+                    start: body[i].start,
+                    end: body[i].end,
+                    value: body[i].body.value
+                });
+            } else if (in_directive && !(body[i] instanceof AST_Statement && body[i].body instanceof AST_String)) {
+                in_directive = false;
+            }
+        }
+
+        return body;
+    };
+
     var MOZ_TO_ME = {
-        TryStatement : function(M) {
+        Program: function(M) {
+            return new AST_Toplevel({
+                start: my_start_token(M),
+                end: my_end_token(M),
+                body: normalize_directives(M.body.map(from_moz))
+            });
+        },
+        FunctionDeclaration: function(M) {
+            return new AST_Defun({
+                start: my_start_token(M),
+                end: my_end_token(M),
+                name: from_moz(M.id),
+                argnames: M.params.map(from_moz),
+                body: normalize_directives(from_moz(M.body).body)
+            });
+        },
+        FunctionExpression: function(M) {
+            return new AST_Function({
+                start: my_start_token(M),
+                end: my_end_token(M),
+                name: from_moz(M.id),
+                argnames: M.params.map(from_moz),
+                body: normalize_directives(from_moz(M.body).body)
+            });
+        },
+        ExpressionStatement: function(M) {
+            return new AST_SimpleStatement({
+                start: my_start_token(M),
+                end: my_end_token(M),
+                body: from_moz(M.expression)
+            });
+        },
+        TryStatement: function(M) {
+            var handlers = M.handlers || [M.handler];
+            if (handlers.length > 1 || M.guardedHandlers && M.guardedHandlers.length) {
+                throw new Error("Multiple catch clauses are not supported.");
+            }
             return new AST_Try({
                 start    : my_start_token(M),
                 end      : my_end_token(M),
                 body     : from_moz(M.block).body,
-                bcatch   : from_moz(M.handlers[0]),
+                bcatch   : from_moz(handlers[0]),
                 bfinally : M.finalizer ? new AST_Finally(from_moz(M.finalizer)) : null
             });
         },
-        CatchClause : function(M) {
-            return new AST_Catch({
-                start   : my_start_token(M),
-                end     : my_end_token(M),
-                argname : from_moz(M.param),
-                body    : from_moz(M.body).body
+        Property: function(M) {
+            var key = M.key;
+            var name = key.type == "Identifier" ? key.name : key.value;
+            var args = {
+                start    : my_start_token(key),
+                end      : my_end_token(M.value),
+                key      : name,
+                value    : from_moz(M.value)
+            };
+            switch (M.kind) {
+              case "init":
+                return new AST_ObjectKeyVal(args);
+              case "set":
+                args.value.name = from_moz(key);
+                return new AST_ObjectSetter(args);
+              case "get":
+                args.value.name = from_moz(key);
+                return new AST_ObjectGetter(args);
+            }
+        },
+        ArrayExpression: function(M) {
+            return new AST_Array({
+                start    : my_start_token(M),
+                end      : my_end_token(M),
+                elements : M.elements.map(function(elem){
+                    return elem === null ? new AST_Hole() : from_moz(elem);
+                })
             });
         },
-        ObjectExpression : function(M) {
+        ObjectExpression: function(M) {
             return new AST_Object({
                 start      : my_start_token(M),
                 end        : my_end_token(M),
                 properties : M.properties.map(function(prop){
-                    var key = prop.key;
-                    var name = key.type == "Identifier" ? key.name : key.value;
-                    var args = {
-                        start    : my_start_token(key),
-                        end      : my_end_token(prop.value),
-                        key      : name,
-                        value    : from_moz(prop.value)
-                    };
-                    switch (prop.kind) {
-                      case "init":
-                        return new AST_ObjectKeyVal(args);
-                      case "set":
-                        args.value.name = from_moz(key);
-                        return new AST_ObjectSetter(args);
-                      case "get":
-                        args.value.name = from_moz(key);
-                        return new AST_ObjectGetter(args);
-                    }
+                    prop.type = "Property";
+                    return from_moz(prop)
                 })
             });
         },
-        SequenceExpression : function(M) {
+        SequenceExpression: function(M) {
             return AST_Seq.from_array(M.expressions.map(from_moz));
         },
-        MemberExpression : function(M) {
+        MemberExpression: function(M) {
             return new (M.computed ? AST_Sub : AST_Dot)({
                 start      : my_start_token(M),
                 end        : my_end_token(M),
@@ -100,7 +159,7 @@
                 expression : from_moz(M.object)
             });
         },
-        SwitchCase : function(M) {
+        SwitchCase: function(M) {
             return new (M.test ? AST_Case : AST_Default)({
                 start      : my_start_token(M),
                 end        : my_end_token(M),
@@ -108,7 +167,14 @@
                 body       : M.consequent.map(from_moz)
             });
         },
-        Literal : function(M) {
+        VariableDeclaration: function(M) {
+            return new (M.kind === "const" ? AST_Const : AST_Var)({
+                start       : my_start_token(M),
+                end         : my_end_token(M),
+                definitions : M.declarations.map(from_moz)
+            });
+        },
+        Literal: function(M) {
             var val = M.value, args = {
                 start  : my_start_token(M),
                 end    : my_end_token(M)
@@ -124,16 +190,20 @@
               case "boolean":
                 return new (val ? AST_True : AST_False)(args);
               default:
-                args.value = val;
+                var rx = M.regex;
+                if (rx && rx.pattern) {
+                    // RegExpLiteral as per ESTree AST spec
+                    args.value = new RegExp(rx.pattern, rx.flags).toString();
+                } else {
+                    // support legacy RegExp
+                    args.value = M.regex && M.raw ? M.raw : val;
+                }
                 return new AST_RegExp(args);
             }
         },
-        UnaryExpression: From_Moz_Unary,
-        UpdateExpression: From_Moz_Unary,
         Identifier: function(M) {
             var p = FROM_MOZ_STACK[FROM_MOZ_STACK.length - 2];
-            return new (M.name == "this" ? AST_This
-                        : p.type == "LabeledStatement" ? AST_Label
+            return new (  p.type == "LabeledStatement" ? AST_Label
                         : p.type == "VariableDeclarator" && p.id === M ? (p.kind == "const" ? AST_SymbolConst : AST_SymbolVar)
                         : p.type == "FunctionExpression" ? (p.id === M ? AST_SymbolLambda : AST_SymbolFunarg)
                         : p.type == "FunctionDeclaration" ? (p.id === M ? AST_SymbolDefun : AST_SymbolFunarg)
@@ -147,23 +217,20 @@
         }
     };
 
-    function From_Moz_Unary(M) {
-        return new (M.prefix ? AST_UnaryPrefix : AST_UnaryPostfix)({
+    MOZ_TO_ME.UpdateExpression =
+    MOZ_TO_ME.UnaryExpression = function To_Moz_Unary(M) {
+        var prefix = "prefix" in M ? M.prefix
+            : M.type == "UnaryExpression" ? true : false;
+        return new (prefix ? AST_UnaryPrefix : AST_UnaryPostfix)({
             start      : my_start_token(M),
             end        : my_end_token(M),
             operator   : M.operator,
             expression : from_moz(M.argument)
-        })
+        });
     };
 
-    var ME_TO_MOZ = {};
-
-    map("Node", AST_Node);
-    map("Program", AST_Toplevel, "body@body");
-    map("Function", AST_Function, "id>name, params@argnames, body%body");
     map("EmptyStatement", AST_EmptyStatement);
     map("BlockStatement", AST_BlockStatement, "body@body");
-    map("ExpressionStatement", AST_SimpleStatement, "expression>body");
     map("IfStatement", AST_If, "test>condition, consequent>body, alternate>alternative");
     map("LabeledStatement", AST_LabeledStatement, "label>label, body>body");
     map("BreakStatement", AST_Break, "label>label");
@@ -177,72 +244,314 @@
     map("ForStatement", AST_For, "init>init, test>condition, update>step, body>body");
     map("ForInStatement", AST_ForIn, "left>init, right>object, body>body");
     map("DebuggerStatement", AST_Debugger);
-    map("FunctionDeclaration", AST_Defun, "id>name, params@argnames, body%body");
-    map("VariableDeclaration", AST_Var, "declarations@definitions");
     map("VariableDeclarator", AST_VarDef, "id>name, init>value");
+    map("CatchClause", AST_Catch, "param>argname, body%body");
 
     map("ThisExpression", AST_This);
-    map("ArrayExpression", AST_Array, "elements@elements");
-    map("FunctionExpression", AST_Function, "id>name, params@argnames, body%body");
     map("BinaryExpression", AST_Binary, "operator=operator, left>left, right>right");
-    map("AssignmentExpression", AST_Assign, "operator=operator, left>left, right>right");
     map("LogicalExpression", AST_Binary, "operator=operator, left>left, right>right");
+    map("AssignmentExpression", AST_Assign, "operator=operator, left>left, right>right");
     map("ConditionalExpression", AST_Conditional, "test>condition, consequent>consequent, alternate>alternative");
     map("NewExpression", AST_New, "callee>expression, arguments@args");
     map("CallExpression", AST_Call, "callee>expression, arguments@args");
 
+    def_to_moz(AST_Toplevel, function To_Moz_Program(M) {
+        return {
+            type: "Program",
+            body: M.body.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_Defun, function To_Moz_FunctionDeclaration(M) {
+        return {
+            type: "FunctionDeclaration",
+            id: to_moz(M.name),
+            params: M.argnames.map(to_moz),
+            body: to_moz_block(M)
+        }
+    });
+
+    def_to_moz(AST_Function, function To_Moz_FunctionExpression(M) {
+        return {
+            type: "FunctionExpression",
+            id: to_moz(M.name),
+            params: M.argnames.map(to_moz),
+            body: to_moz_block(M)
+        }
+    });
+
+    def_to_moz(AST_Directive, function To_Moz_Directive(M) {
+        return {
+            type: "ExpressionStatement",
+            expression: {
+                type: "Literal",
+                value: M.value
+            }
+        };
+    });
+
+    def_to_moz(AST_SimpleStatement, function To_Moz_ExpressionStatement(M) {
+        return {
+            type: "ExpressionStatement",
+            expression: to_moz(M.body)
+        };
+    });
+
+    def_to_moz(AST_SwitchBranch, function To_Moz_SwitchCase(M) {
+        return {
+            type: "SwitchCase",
+            test: to_moz(M.expression),
+            consequent: M.body.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_Try, function To_Moz_TryStatement(M) {
+        return {
+            type: "TryStatement",
+            block: to_moz_block(M),
+            handler: to_moz(M.bcatch),
+            guardedHandlers: [],
+            finalizer: to_moz(M.bfinally)
+        };
+    });
+
+    def_to_moz(AST_Catch, function To_Moz_CatchClause(M) {
+        return {
+            type: "CatchClause",
+            param: to_moz(M.argname),
+            guard: null,
+            body: to_moz_block(M)
+        };
+    });
+
+    def_to_moz(AST_Definitions, function To_Moz_VariableDeclaration(M) {
+        return {
+            type: "VariableDeclaration",
+            kind: M instanceof AST_Const ? "const" : "var",
+            declarations: M.definitions.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_Seq, function To_Moz_SequenceExpression(M) {
+        return {
+            type: "SequenceExpression",
+            expressions: M.to_array().map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_PropAccess, function To_Moz_MemberExpression(M) {
+        var isComputed = M instanceof AST_Sub;
+        return {
+            type: "MemberExpression",
+            object: to_moz(M.expression),
+            computed: isComputed,
+            property: isComputed ? to_moz(M.property) : {type: "Identifier", name: M.property}
+        };
+    });
+
+    def_to_moz(AST_Unary, function To_Moz_Unary(M) {
+        return {
+            type: M.operator == "++" || M.operator == "--" ? "UpdateExpression" : "UnaryExpression",
+            operator: M.operator,
+            prefix: M instanceof AST_UnaryPrefix,
+            argument: to_moz(M.expression)
+        };
+    });
+
+    def_to_moz(AST_Binary, function To_Moz_BinaryExpression(M) {
+        return {
+            type: M.operator == "&&" || M.operator == "||" ? "LogicalExpression" : "BinaryExpression",
+            left: to_moz(M.left),
+            operator: M.operator,
+            right: to_moz(M.right)
+        };
+    });
+
+    def_to_moz(AST_Array, function To_Moz_ArrayExpression(M) {
+        return {
+            type: "ArrayExpression",
+            elements: M.elements.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_Object, function To_Moz_ObjectExpression(M) {
+        return {
+            type: "ObjectExpression",
+            properties: M.properties.map(to_moz)
+        };
+    });
+
+    def_to_moz(AST_ObjectProperty, function To_Moz_Property(M) {
+        var key = (
+            is_identifier(M.key)
+            ? {type: "Identifier", name: M.key}
+            : {type: "Literal", value: M.key}
+        );
+        var kind;
+        if (M instanceof AST_ObjectKeyVal) {
+            kind = "init";
+        } else
+        if (M instanceof AST_ObjectGetter) {
+            kind = "get";
+        } else
+        if (M instanceof AST_ObjectSetter) {
+            kind = "set";
+        }
+        return {
+            type: "Property",
+            kind: kind,
+            key: key,
+            value: to_moz(M.value)
+        };
+    });
+
+    def_to_moz(AST_Symbol, function To_Moz_Identifier(M) {
+        var def = M.definition();
+        return {
+            type: "Identifier",
+            name: def ? def.mangled_name || def.name : M.name
+        };
+    });
+
+    def_to_moz(AST_RegExp, function To_Moz_RegExpLiteral(M) {
+        var value = M.value;
+        return {
+            type: "Literal",
+            value: value,
+            raw: value.toString(),
+            regex: {
+                pattern: value.source,
+                flags: value.toString().match(/[gimuy]*$/)[0]
+            }
+        };
+    });
+
+    def_to_moz(AST_Constant, function To_Moz_Literal(M) {
+        var value = M.value;
+        if (typeof value === 'number' && (value < 0 || (value === 0 && 1 / value < 0))) {
+            return {
+                type: "UnaryExpression",
+                operator: "-",
+                prefix: true,
+                argument: {
+                    type: "Literal",
+                    value: -value,
+                    raw: M.start.raw
+                }
+            };
+        }
+        return {
+            type: "Literal",
+            value: value,
+            raw: M.start.raw
+        };
+    });
+
+    def_to_moz(AST_Atom, function To_Moz_Atom(M) {
+        return {
+            type: "Identifier",
+            name: String(M.value)
+        };
+    });
+
+    AST_Boolean.DEFMETHOD("to_mozilla_ast", AST_Constant.prototype.to_mozilla_ast);
+    AST_Null.DEFMETHOD("to_mozilla_ast", AST_Constant.prototype.to_mozilla_ast);
+    AST_Hole.DEFMETHOD("to_mozilla_ast", function To_Moz_ArrayHole() { return null });
+
+    AST_Block.DEFMETHOD("to_mozilla_ast", AST_BlockStatement.prototype.to_mozilla_ast);
+    AST_Lambda.DEFMETHOD("to_mozilla_ast", AST_Function.prototype.to_mozilla_ast);
+
     /* -----[ tools ]----- */
 
+    function raw_token(moznode) {
+        if (moznode.type == "Literal") {
+            return moznode.raw != null ? moznode.raw : moznode.value + "";
+        }
+    }
+
     function my_start_token(moznode) {
+        var loc = moznode.loc, start = loc && loc.start;
+        var range = moznode.range;
         return new AST_Token({
-            file   : moznode.loc && moznode.loc.source,
-            line   : moznode.loc && moznode.loc.start.line,
-            col    : moznode.loc && moznode.loc.start.column,
-            pos    : moznode.start,
-            endpos : moznode.start
+            file    : loc && loc.source,
+            line    : start && start.line,
+            col     : start && start.column,
+            pos     : range ? range[0] : moznode.start,
+            endline : start && start.line,
+            endcol  : start && start.column,
+            endpos  : range ? range[0] : moznode.start,
+            raw     : raw_token(moznode),
         });
     };
 
     function my_end_token(moznode) {
+        var loc = moznode.loc, end = loc && loc.end;
+        var range = moznode.range;
         return new AST_Token({
-            file   : moznode.loc && moznode.loc.source,
-            line   : moznode.loc && moznode.loc.end.line,
-            col    : moznode.loc && moznode.loc.end.column,
-            pos    : moznode.end,
-            endpos : moznode.end
+            file    : loc && loc.source,
+            line    : end && end.line,
+            col     : end && end.column,
+            pos     : range ? range[1] : moznode.end,
+            endline : end && end.line,
+            endcol  : end && end.column,
+            endpos  : range ? range[1] : moznode.end,
+            raw     : raw_token(moznode),
         });
     };
 
     function map(moztype, mytype, propmap) {
         var moz_to_me = "function From_Moz_" + moztype + "(M){\n";
-        moz_to_me += "return new mytype({\n" +
+        moz_to_me += "return new U2." + mytype.name + "({\n" +
             "start: my_start_token(M),\n" +
             "end: my_end_token(M)";
 
+        var me_to_moz = "function To_Moz_" + moztype + "(M){\n";
+        me_to_moz += "return {\n" +
+            "type: " + JSON.stringify(moztype);
+
         if (propmap) propmap.split(/\s*,\s*/).forEach(function(prop){
             var m = /([a-z0-9$_]+)(=|@|>|%)([a-z0-9$_]+)/i.exec(prop);
             if (!m) throw new Error("Can't understand property map: " + prop);
-            var moz = "M." + m[1], how = m[2], my = m[3];
+            var moz = m[1], how = m[2], my = m[3];
             moz_to_me += ",\n" + my + ": ";
-            if (how == "@") {
-                moz_to_me += moz + ".map(from_moz)";
-            } else if (how == ">") {
-                moz_to_me += "from_moz(" + moz + ")";
-            } else if (how == "=") {
-                moz_to_me += moz;
-            } else if (how == "%") {
-                moz_to_me += "from_moz(" + moz + ").body";
-            } else throw new Error("Can't understand operator in propmap: " + prop);
+            me_to_moz += ",\n" + moz + ": ";
+            switch (how) {
+                case "@":
+                    moz_to_me += "M." + moz + ".map(from_moz)";
+                    me_to_moz += "M." +  my + ".map(to_moz)";
+                    break;
+                case ">":
+                    moz_to_me += "from_moz(M." + moz + ")";
+                    me_to_moz += "to_moz(M." + my + ")";
+                    break;
+                case "=":
+                    moz_to_me += "M." + moz;
+                    me_to_moz += "M." + my;
+                    break;
+                case "%":
+                    moz_to_me += "from_moz(M." + moz + ").body";
+                    me_to_moz += "to_moz_block(M)";
+                    break;
+                default:
+                    throw new Error("Can't understand operator in propmap: " + prop);
+            }
         });
-        moz_to_me += "\n})}";
 
-        // moz_to_me = parse(moz_to_me).print_to_string({ beautify: true });
-        // console.log(moz_to_me);
+        moz_to_me += "\n})\n}";
+        me_to_moz += "\n}\n}";
 
-        moz_to_me = new Function("mytype", "my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
-            mytype, my_start_token, my_end_token, from_moz
+        //moz_to_me = parse(moz_to_me).print_to_string({ beautify: true });
+        //me_to_moz = parse(me_to_moz).print_to_string({ beautify: true });
+        //console.log(moz_to_me);
+
+        moz_to_me = new Function("U2", "my_start_token", "my_end_token", "from_moz", "return(" + moz_to_me + ")")(
+            exports, my_start_token, my_end_token, from_moz
         );
-        return MOZ_TO_ME[moztype] = moz_to_me;
+        me_to_moz = new Function("to_moz", "to_moz_block", "return(" + me_to_moz + ")")(
+            to_moz, to_moz_block
+        );
+        MOZ_TO_ME[moztype] = moz_to_me;
+        def_to_moz(mytype, me_to_moz);
     };
 
     var FROM_MOZ_STACK = null;
@@ -262,4 +571,39 @@
         return ast;
     };
 
+    function set_moz_loc(mynode, moznode, myparent) {
+        var start = mynode.start;
+        var end = mynode.end;
+        if (start.pos != null && end.endpos != null) {
+            moznode.range = [start.pos, end.endpos];
+        }
+        if (start.line) {
+            moznode.loc = {
+                start: {line: start.line, column: start.col},
+                end: end.endline ? {line: end.endline, column: end.endcol} : null
+            };
+            if (start.file) {
+                moznode.loc.source = start.file;
+            }
+        }
+        return moznode;
+    };
+
+    function def_to_moz(mytype, handler) {
+        mytype.DEFMETHOD("to_mozilla_ast", function() {
+            return set_moz_loc(this, handler(this));
+        });
+    };
+
+    function to_moz(node) {
+        return node != null ? node.to_mozilla_ast() : null;
+    };
+
+    function to_moz_block(node) {
+        return {
+            type: "BlockStatement",
+            body: node.body.map(to_moz)
+        };
+    };
+
 })();

lib/propmangle.js

@@ -0,0 +1,282 @@
+/***********************************************************************
+
+  A JavaScript tokenizer / parser / beautifier / compressor.
+  https://github.com/mishoo/UglifyJS2
+
+  -------------------------------- (C) ---------------------------------
+
+                           Author: Mihai Bazon
+                         <mihai.bazon@gmail.com>
+                       http://mihai.bazon.net/blog
+
+  Distributed under the BSD license:
+
+    Copyright 2012 (c) Mihai Bazon <mihai.bazon@gmail.com>
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+        * Redistributions of source code must retain the above
+          copyright notice, this list of conditions and the following
+          disclaimer.
+
+        * Redistributions in binary form must reproduce the above
+          copyright notice, this list of conditions and the following
+          disclaimer in the documentation and/or other materials
+          provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
+    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+ ***********************************************************************/
+
+"use strict";
+
+function find_builtins() {
+
+    // Compatibility fix for some standard defined globals not defined on every js environment
+    var new_globals = ["Symbol", "Map", "Promise", "Proxy", "Reflect", "Set", "WeakMap", "WeakSet"];
+    var objects = {};
+
+    new_globals.forEach(function (new_global) {
+        objects[new_global] = global[new_global] || new Function();
+    });
+
+    var a = [];
+    [ Object, Array, Function, Number,
+      String, Boolean, Error, Math,
+      Date, RegExp, objects.Symbol, ArrayBuffer,
+      DataView, decodeURI, decodeURIComponent,
+      encodeURI, encodeURIComponent, eval, EvalError,
+      Float32Array, Float64Array, Int8Array, Int16Array,
+      Int32Array, isFinite, isNaN, JSON, objects.Map, parseFloat,
+      parseInt, objects.Promise, objects.Proxy, RangeError, ReferenceError,
+      objects.Reflect, objects.Set, SyntaxError, TypeError, Uint8Array,
+      Uint8ClampedArray, Uint16Array, Uint32Array, URIError,
+      objects.WeakMap, objects.WeakSet
+    ].forEach(function(ctor){
+        Object.getOwnPropertyNames(ctor).map(add);
+        if (ctor.prototype) {
+            Object.getOwnPropertyNames(ctor.prototype).map(add);
+        }
+    });
+    function add(name) {
+        push_uniq(a, name);
+    }
+    return a;
+}
+
+function mangle_properties(ast, options) {
+    options = defaults(options, {
+        reserved : null,
+        cache : null,
+        only_cache : false,
+        regex : null,
+        ignore_quoted : false,
+        debug : false
+    });
+
+    var reserved = options.reserved;
+    if (reserved == null)
+        reserved = find_builtins();
+
+    var cache = options.cache;
+    if (cache == null) {
+        cache = {
+            cname: -1,
+            props: new Dictionary()
+        };
+    }
+
+    var regex = options.regex;
+    var ignore_quoted = options.ignore_quoted;
+
+    // note debug is either false (disabled), or a string of the debug suffix to use (enabled).
+    // note debug may be enabled as an empty string, which is falsey. Also treat passing 'true'
+    // the same as passing an empty string.
+    var debug = (options.debug !== false);
+    var debug_name_suffix;
+    if (debug) {
+        debug_name_suffix = (options.debug === true ? "" : options.debug);
+    }
+
+    var names_to_mangle = [];
+    var unmangleable = [];
+    var ignored = {};
+
+    // step 1: find candidates to mangle
+    ast.walk(new TreeWalker(function(node){
+        if (node instanceof AST_ObjectKeyVal) {
+            add(node.key, ignore_quoted && node.quote);
+        }
+        else if (node instanceof AST_ObjectProperty) {
+            // setter or getter, since KeyVal is handled above
+            add(node.key.name);
+        }
+        else if (node instanceof AST_Dot) {
+            add(node.property);
+        }
+        else if (node instanceof AST_Sub) {
+            addStrings(node.property, ignore_quoted);
+        }
+        else if (node instanceof AST_ConciseMethod) {
+            add(node.name.name);
+        }
+    }));
+
+    // step 2: transform the tree, renaming properties
+    return ast.transform(new TreeTransformer(function(node){
+        if (node instanceof AST_ObjectKeyVal) {
+            if (!(ignore_quoted && node.quote))
+                node.key = mangle(node.key);
+        }
+        else if (node instanceof AST_ObjectProperty) {
+            // setter or getter
+            node.key.name = mangle(node.key.name);
+        }
+        else if (node instanceof AST_Dot) {
+            node.property = mangle(node.property);
+        }
+        else if (node instanceof AST_Sub) {
+            if (!ignore_quoted)
+                node.property = mangleStrings(node.property);
+        }
+        else if (node instanceof AST_ConciseMethod) {
+            if (should_mangle(node.name.name)) {
+                node.name.name = mangle(node.name.name);
+            }
+        }
+        // else if (node instanceof AST_String) {
+        //     if (should_mangle(node.value)) {
+        //         AST_Node.warn(
+        //             "Found \"{prop}\" property candidate for mangling in an arbitrary string [{file}:{line},{col}]", {
+        //                 file : node.start.file,
+        //                 line : node.start.line,
+        //                 col  : node.start.col,
+        //                 prop : node.value
+        //             }
+        //         );
+        //     }
+        // }
+    }));
+
+    // only function declarations after this line
+
+    function can_mangle(name) {
+        if (!is_identifier(name)) return false;
+        if (unmangleable.indexOf(name) >= 0) return false;
+        if (reserved.indexOf(name) >= 0) return false;
+        if (options.only_cache) {
+            return cache.props.has(name);
+        }
+        if (/^[0-9.]+$/.test(name)) return false;
+        return true;
+    }
+
+    function should_mangle(name) {
+        if (ignore_quoted && name in ignored) return false;
+        if (regex && !regex.test(name)) return false;
+        if (reserved.indexOf(name) >= 0) return false;
+        return cache.props.has(name)
+            || names_to_mangle.indexOf(name) >= 0;
+    }
+
+    function add(name, ignore) {
+        if (ignore) {
+            ignored[name] = true;
+            return;
+        }
+
+        if (can_mangle(name))
+            push_uniq(names_to_mangle, name);
+
+        if (!should_mangle(name)) {
+            push_uniq(unmangleable, name);
+        }
+    }
+
+    function mangle(name) {
+        if (!should_mangle(name)) {
+            return name;
+        }
+
+        var mangled = cache.props.get(name);
+        if (!mangled) {
+            if (debug) {
+                // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
+                var debug_mangled = "_$" + name + "$" + debug_name_suffix + "_";
+
+                if (can_mangle(debug_mangled) && !(ignore_quoted && debug_mangled in ignored)) {
+                    mangled = debug_mangled;
+                }
+            }
+
+            // either debug mode is off, or it is on and we could not use the mangled name
+            if (!mangled) {
+                // note can_mangle() does not check if the name collides with the 'ignored' set
+                // (filled with quoted properties when ignore_quoted set). Make sure we add this
+                // check so we don't collide with a quoted name.
+                do {
+                    mangled = base54(++cache.cname);
+                } while (!can_mangle(mangled) || (ignore_quoted && mangled in ignored));
+            }
+
+            cache.props.set(name, mangled);
+        }
+        return mangled;
+    }
+
+    function addStrings(node, ignore) {
+        var out = {};
+        try {
+            (function walk(node){
+                node.walk(new TreeWalker(function(node){
+                    if (node instanceof AST_Seq) {
+                        walk(node.cdr);
+                        return true;
+                    }
+                    if (node instanceof AST_String) {
+                        add(node.value, ignore);
+                        return true;
+                    }
+                    if (node instanceof AST_Conditional) {
+                        walk(node.consequent);
+                        walk(node.alternative);
+                        return true;
+                    }
+                    throw out;
+                }));
+            })(node);
+        } catch(ex) {
+            if (ex !== out) throw ex;
+        }
+    }
+
+    function mangleStrings(node) {
+        return node.transform(new TreeTransformer(function(node){
+            if (node instanceof AST_Seq) {
+                node.cdr = mangleStrings(node.cdr);
+            }
+            else if (node instanceof AST_String) {
+                node.value = mangle(node.value);
+            }
+            else if (node instanceof AST_Conditional) {
+                node.consequent = mangleStrings(node.consequent);
+                node.alternative = mangleStrings(node.alternative);
+            }
+            return node;
+        }));
+    }
+
+}

lib/scope.js

@@ -49,87 +49,147 @@ function SymbolDef(scope, index, orig) {
     this.scope = scope;
     this.references = [];
     this.global = false;
+    this.export = false;
     this.mangled_name = null;
+    this.object_destructuring_arg = false;
     this.undeclared = false;
-    this.constant = false;
     this.index = index;
+    this.id = SymbolDef.next_id++;
 };
 
+SymbolDef.next_id = 1;
+
 SymbolDef.prototype = {
     unmangleable: function(options) {
-        return this.global
+        if (!options) options = {};
+
+        return (this.global && !options.toplevel)
+            || this.export
+            || this.object_destructuring_arg
             || this.undeclared
-            || (!(options && options.eval) && (this.scope.uses_eval || this.scope.uses_with));
+            || (!options.eval && (this.scope.uses_eval || this.scope.uses_with))
+            || (options.keep_fnames
+                && (this.orig[0] instanceof AST_SymbolLambda
+                    || this.orig[0] instanceof AST_SymbolDefun))
+            || this.orig[0] instanceof AST_SymbolMethod
+            || (options.keep_classnames
+                && (this.orig[0] instanceof AST_SymbolClass
+                    || this.orig[0] instanceof AST_SymbolDefClass));
     },
     mangle: function(options) {
-        if (!this.mangled_name && !this.unmangleable(options))
-            this.mangled_name = this.scope.next_mangled(options);
+        var cache = options.cache && options.cache.props;
+        if (this.global && cache && cache.has(this.name)) {
+            this.mangled_name = cache.get(this.name);
+        }
+        else if (!this.mangled_name && !this.unmangleable(options)) {
+            var s = this.scope;
+            var sym = this.orig[0];
+            if (!options.screw_ie8 && sym instanceof AST_SymbolLambda)
+                s = s.parent_scope;
+            var def;
+            if (options.screw_ie8
+                && sym instanceof AST_SymbolCatch
+                && (def = s.parent_scope.find_variable(sym))) {
+                this.mangled_name = def.mangled_name || def.name;
+            } else
+                this.mangled_name = s.next_mangled(options, this);
+            if (this.global && cache) {
+                cache.set(this.name, this.mangled_name);
+            }
+        }
     }
 };
 
-AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
-    // This does what ast_add_scope did in UglifyJS v1.
-    //
-    // Part of it could be done at parse time, but it would complicate
-    // the parser (and it's already kinda complex).  It's also worth
-    // having it separated because we might need to call it multiple
-    // times on the same tree.
+AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
+    options = defaults(options, {
+        screw_ie8: true,
+        cache: null
+    });
 
     // pass 1: setup scope chaining and handle definitions
     var self = this;
     var scope = self.parent_scope = null;
     var labels = new Dictionary();
-    var nesting = 0;
+    var defun = null;
+    var in_destructuring = null;
+    var in_export = false;
+    var in_block = 0;
     var tw = new TreeWalker(function(node, descend){
-        if (node instanceof AST_Scope) {
-            node.init_scope_vars(nesting);
-            var save_scope = node.parent_scope = scope;
-            ++nesting;
-            scope = node;
+        if (node.is_block_scope()) {
+            var save_scope = scope;
+            scope = new AST_Scope(node);
+            scope.init_scope_vars(save_scope);
+            if (!(node instanceof AST_Scope)) {
+                scope.uses_with = save_scope.uses_with;
+                scope.uses_eval = save_scope.uses_eval;
+                scope.directives = save_scope.directives;
+            }
             descend();
             scope = save_scope;
-            --nesting;
+            return true;
+        }
+        if (node instanceof AST_Destructuring && node.is_array === false) {
+            in_destructuring = node;  // These don't nest
+            descend();
+            in_destructuring = null;
+            return true;
+        }
+        if (node instanceof AST_Scope) {
+            node.init_scope_vars(scope);
+            var save_scope = scope;
+            var save_defun = defun;
+            var save_labels = labels;
+            defun = scope = node;
+            labels = new Dictionary();
+            descend();
+            scope = save_scope;
+            defun = save_defun;
+            labels = save_labels;
             return true;        // don't descend again in TreeWalker
         }
-        if (node instanceof AST_Directive) {
-            node.scope = scope;
-            push_uniq(scope.directives, node.value);
+        if (node instanceof AST_Export) {
+            in_export = true;
+            descend();
+            in_export = false;
             return true;
         }
+        if (node instanceof AST_BlockStatement
+            || node instanceof AST_Switch
+            || node instanceof AST_Try
+            || node instanceof AST_Catch
+            || node instanceof AST_Finally) {
+            in_block++;
+            descend();
+            in_block--;
+            return true;
+        }
+        if (node instanceof AST_LabeledStatement) {
+            var l = node.label;
+            if (labels.has(l.name)) {
+                throw new Error(string_template("Label {name} defined twice", l));
+            }
+            labels.set(l.name, l);
+            descend();
+            labels.del(l.name);
+            return true;        // no descend again
+        }
         if (node instanceof AST_With) {
             for (var s = scope; s; s = s.parent_scope)
                 s.uses_with = true;
             return;
         }
-        if (node instanceof AST_LabeledStatement) {
-            var l = node.label;
-            if (labels.has(l.name))
-                throw new Error(string_template("Label {name} defined twice", l));
-            labels.set(l.name, l);
-            descend();
-            labels.del(l.name);
-            return true;        // no descend again
-        }
-        if (node instanceof AST_SymbolDeclaration) {
-            node.init_scope_vars();
-        }
         if (node instanceof AST_Symbol) {
             node.scope = scope;
         }
+        if (node instanceof AST_SymbolFunarg) {
+            node.object_destructuring_arg = !!in_destructuring;
+        }
         if (node instanceof AST_Label) {
             node.thedef = node;
-            node.init_scope_vars();
+            node.references = [];
         }
         if (node instanceof AST_SymbolLambda) {
-            //scope.def_function(node);
-            //
-            // https://github.com/mishoo/UglifyJS2/issues/24 — MSIE
-            // leaks function expression names into the containing
-            // scope.  Don't like this fix but seems we can't do any
-            // better.  IE: please die. Please!
-            (node.scope = scope.parent_scope).def_function(node);
-
-            node.init.push(tw.parent());
+            defun.def_function(node, in_export, in_block);
         }
         else if (node instanceof AST_SymbolDefun) {
             // Careful here, the scope where this should be defined is
@@ -137,26 +197,41 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             // scope when we encounter the AST_Defun node (which is
             // instanceof AST_Scope) but we get to the symbol a bit
             // later.
-            (node.scope = scope.parent_scope).def_function(node);
-            node.init.push(tw.parent());
+            var parent_lambda = defun.parent_scope;
+            while (parent_lambda.is_block_scope()) {
+                parent_lambda = parent_lambda.parent_scope;
+            }
+            (node.scope = parent_lambda).def_function(node, in_export, in_block);
+        }
+        else if (node instanceof AST_SymbolClass) {
+            defun.def_variable(node, in_export, in_block);
+        }
+        else if (node instanceof AST_SymbolImport) {
+            scope.def_variable(node, in_export, in_block);
+        }
+        else if (node instanceof AST_SymbolDefClass) {
+            // This deals with the name of the class being available
+            // inside the class.
+            (node.scope = defun.parent_scope).def_function(node, in_export, in_block);
         }
         else if (node instanceof AST_SymbolVar
-                 || node instanceof AST_SymbolConst) {
-            var def = scope.def_variable(node);
-            def.constant = node instanceof AST_SymbolConst;
-            def = tw.parent();
-            if (def.value) node.init.push(def);
+            || node instanceof AST_SymbolLet
+            || node instanceof AST_SymbolConst) {
+            var def = ((node instanceof AST_SymbolBlockDeclaration) ? scope : defun).def_variable(node, in_export, in_block);
+            def.destructuring = in_destructuring;
+            if (defun !== scope) {
+                node.mark_enclosed(options);
+                var def = scope.find_variable(node);
+                if (node.thedef !== def) {
+                    node.thedef = def;
+                    node.reference(options);
+                }
+            }
         }
         else if (node instanceof AST_SymbolCatch) {
-            // XXX: this is wrong according to ECMA-262 (12.4).  the
-            // `catch` argument name should be visible only inside the
-            // catch block.  For a quick fix AST_Catch should inherit
-            // from AST_Scope.  Keeping it this way because of IE,
-            // which doesn't obey the standard. (it introduces the
-            // identifier in the enclosing scope)
-            scope.def_variable(node);
+            scope.def_variable(node, in_export, in_block);
         }
-        if (node instanceof AST_LabelRef) {
+        else if (node instanceof AST_LabelRef) {
             var sym = labels.get(node.name);
             if (!sym) throw new Error(string_template("Undefined label {name} [{line},{col}]", {
                 name: node.name,
@@ -170,6 +245,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
 
     // pass 2: find back references and eval
     var func = null;
+    var cls = null;
     var globals = self.globals = new Dictionary();
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_Lambda) {
@@ -179,83 +255,129 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             func = prev_func;
             return true;
         }
-        if (node instanceof AST_LabelRef) {
-            node.reference();
+        if (node instanceof AST_Class) {
+            var prev_cls = cls;
+            cls = node;
+            descend();
+            cls = prev_cls;
+            return true;
+        }
+        if (node instanceof AST_LoopControl && node.label) {
+            node.label.thedef.references.push(node);
             return true;
         }
         if (node instanceof AST_SymbolRef) {
             var name = node.name;
-            var sym = node.scope.find_variable(name);
-            if (!sym) {
-                var g;
-                if (globals.has(name)) {
-                    g = globals.get(name);
-                } else {
-                    g = new SymbolDef(self, globals.size(), node);
-                    g.undeclared = true;
-                    globals.set(name, g);
+            if (name == "eval" && tw.parent() instanceof AST_Call) {
+                for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
+                    s.uses_eval = true;
                 }
-                node.thedef = g;
-                if (name == "eval" && tw.parent() instanceof AST_Call) {
-                    for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope)
-                        s.uses_eval = true;
-                }
-                if (name == "arguments") {
-                    func.uses_arguments = true;
-                }
-            } else {
-                node.thedef = sym;
             }
-            node.reference();
+            var sym = node.scope.find_variable(name);
+            if (node.scope instanceof AST_Lambda && name == "arguments") {
+                node.scope.uses_arguments = true;
+            }
+            if (!sym) {
+                sym = self.def_global(node);
+            }
+            node.thedef = sym;
+            node.reference(options);
             return true;
         }
     });
     self.walk(tw);
+
+    // pass 3: fix up any scoping issue with IE8
+    if (!options.screw_ie8) {
+        self.walk(new TreeWalker(function(node, descend) {
+            if (node instanceof AST_SymbolCatch) {
+                var name = node.name;
+                var refs = node.thedef.references;
+                var scope = node.thedef.scope.parent_scope.parent_scope;
+                var def = scope.find_variable(name) || self.globals.get(name) || scope.def_variable(node);
+                refs.forEach(function(ref) {
+                    ref.thedef = def;
+                    ref.reference(options);
+                });
+                node.thedef = def;
+                return true;
+            }
+        }));
+    }
+
+    if (options.cache) {
+        this.cname = options.cache.cname;
+    }
 });
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(nesting){
-    this.directives = [];     // contains the directives defined in this scope, i.e. "use strict"
-    this.variables = new Dictionary(); // map name to AST_SymbolVar (variables defined in this scope; includes functions)
-    this.functions = new Dictionary(); // map name to AST_SymbolDefun (functions defined in this scope)
-    this.uses_with = false;   // will be set to true if this or some nested scope uses the `with` statement
-    this.uses_eval = false;   // will be set to true if this or nested scope uses the global `eval`
-    this.parent_scope = null; // the parent scope
-    this.enclosed = [];       // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
-    this.cname = -1;          // the current index for mangling functions/variables
-    this.nesting = nesting;   // the nesting level of this scope (0 means toplevel)
+AST_Toplevel.DEFMETHOD("def_global", function(node){
+    var globals = this.globals, name = node.name;
+    if (globals.has(name)) {
+        return globals.get(name);
+    } else {
+        var g = new SymbolDef(this, globals.size(), node);
+        g.undeclared = true;
+        g.global = true;
+        globals.set(name, g);
+        return g;
+    }
 });
 
-AST_Scope.DEFMETHOD("strict", function(){
-    return this.has_directive("use strict");
+AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope){
+    this.variables = new Dictionary();  // map name to AST_SymbolVar (variables defined in this scope; includes functions)
+    this.functions = new Dictionary();  // map name to AST_SymbolDefun (functions defined in this scope)
+    this.uses_with = false;             // will be set to true if this or some nested scope uses the `with` statement
+    this.uses_eval = false;             // will be set to true if this or nested scope uses the global `eval`
+    this.parent_scope = parent_scope;   // the parent scope
+    this.enclosed = [];                 // a list of variables from this or outer scope(s) that are referenced from this or inner scopes
+    this.cname = -1;                    // the current index for mangling functions/variables
+});
+
+AST_Node.DEFMETHOD("is_block_scope", function(){
+    return false; // Behaviour will be overridden by AST_Block
+});
+
+AST_Block.DEFMETHOD("is_block_scope", function(){
+    return (
+        !(this instanceof AST_Lambda) &&
+        !(this instanceof AST_Toplevel) &&
+        !(this instanceof AST_Class) &&
+        !(this instanceof AST_SwitchBranch)
+    );
+});
+
+AST_IterationStatement.DEFMETHOD("is_block_scope", function(){
+     return true;
 });
 
 AST_Lambda.DEFMETHOD("init_scope_vars", function(){
     AST_Scope.prototype.init_scope_vars.apply(this, arguments);
     this.uses_arguments = false;
+    this.def_variable(new AST_SymbolVar({
+        name: "arguments",
+        start: this.start,
+        end: this.end
+    }));
 });
 
-AST_SymbolRef.DEFMETHOD("reference", function() {
+AST_Symbol.DEFMETHOD("mark_enclosed", function(options) {
     var def = this.definition();
-    def.references.push(this);
     var s = this.scope;
     while (s) {
         push_uniq(s.enclosed, def);
+        if (options.keep_fnames) {
+            s.functions.each(function(d) {
+                push_uniq(def.scope.enclosed, d);
+            });
+        }
         if (s === def.scope) break;
         s = s.parent_scope;
     }
-    this.frame = this.scope.nesting - def.scope.nesting;
 });
 
-AST_SymbolDeclaration.DEFMETHOD("init_scope_vars", function(){
-    this.init = [];
-});
-
-AST_Label.DEFMETHOD("init_scope_vars", function(){
-    this.references = [];
-});
-
-AST_LabelRef.DEFMETHOD("reference", function(){
-    this.thedef.references.push(this);
+AST_Symbol.DEFMETHOD("reference", function(options) {
+    this.definition().references.push(this);
+    this.mark_enclosed(options);
 });
 
 AST_Scope.DEFMETHOD("find_variable", function(name){
@@ -264,21 +386,24 @@ AST_Scope.DEFMETHOD("find_variable", function(name){
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
-AST_Scope.DEFMETHOD("has_directive", function(value){
-    return this.parent_scope && this.parent_scope.has_directive(value)
-        || (this.directives.indexOf(value) >= 0 ? this : null);
+AST_Scope.DEFMETHOD("def_function", function(symbol, in_export, in_block){
+    this.functions.set(symbol.name, this.def_variable(symbol, in_export, in_block));
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol){
-    this.functions.set(symbol.name, this.def_variable(symbol));
-});
-
-AST_Scope.DEFMETHOD("def_variable", function(symbol){
+AST_Scope.DEFMETHOD("def_variable", function(symbol, in_export, in_block){
     var def;
     if (!this.variables.has(symbol.name)) {
         def = new SymbolDef(this, this.variables.size(), symbol);
         this.variables.set(symbol.name, def);
-        def.global = !this.parent_scope;
+        def.object_destructuring_arg = symbol.object_destructuring_arg;
+        if (in_export) {
+            def.export = true;
+        }
+        if (in_block && symbol instanceof AST_SymbolBlockDeclaration) {
+            def.global = false;
+        } else {
+            def.global = !this.parent_scope;
+        }
     } else {
         def = this.variables.get(symbol.name);
         def.orig.push(symbol);
@@ -287,14 +412,19 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol){
 });
 
 AST_Scope.DEFMETHOD("next_mangled", function(options){
-    var ext = this.enclosed, n = ext.length;
+    var ext = this.enclosed;
     out: while (true) {
         var m = base54(++this.cname);
         if (!is_identifier(m)) continue; // skip over "do"
+
+        // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
+        // shadow a name excepted from mangling.
+        if (options.except.indexOf(m) >= 0) continue;
+
         // we must ensure that the mangled name does not shadow a name
         // from some parent scope that is referenced in this or in
         // inner scopes.
-        for (var i = n; --i >= 0;) {
+        for (var i = ext.length; --i >= 0;) {
             var sym = ext[i];
             var name = sym.mangled_name || (sym.unmangleable(options) && sym.name);
             if (m == name) continue out;
@@ -303,13 +433,26 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
     }
 });
 
-AST_Scope.DEFMETHOD("references", function(sym){
-    if (sym instanceof AST_Symbol) sym = sym.definition();
-    return this.enclosed.indexOf(sym) < 0 ? null : sym;
+AST_Function.DEFMETHOD("next_mangled", function(options, def){
+    // #179, #326
+    // in Safari strict mode, something like (function x(x){...}) is a syntax error;
+    // a function expression's argument cannot shadow the function expression's name
+
+    var tricky_def = def.orig[0] instanceof AST_SymbolFunarg && this.name && this.name.definition();
+
+    // the function's mangled_name is null when keep_fnames is true
+    var tricky_name = tricky_def ? tricky_def.mangled_name || tricky_def.name : null;
+
+    while (true) {
+        var name = AST_Lambda.prototype.next_mangled.call(this, options, def);
+        if (!tricky_name || tricky_name != name)
+            return name;
+    }
 });
 
 AST_Symbol.DEFMETHOD("unmangleable", function(options){
-    return this.definition().unmangleable(options);
+    var def = this.definition();
+    return def && def.unmangleable(options);
 });
 
 // property accessors are not mangleable
@@ -349,19 +492,37 @@ AST_Symbol.DEFMETHOD("global", function(){
 
 AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options){
     return defaults(options, {
-        except : [],
-        eval   : false,
+        except      : [],
+        eval        : false,
+        sort        : false, // Ignored. Flag retained for backwards compatibility.
+        toplevel    : false,
+        screw_ie8   : true,
+        keep_fnames : false,
+        keep_classnames : false
     });
 });
 
 AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     options = this._default_mangler_options(options);
+
+    // Never mangle arguments
+    options.except.push('arguments');
+
     // We only need to mangle declaration nodes.  Special logic wired
     // into the code generator will display the mangled name if it's
     // present (and for AST_SymbolRef-s it'll use the mangled name of
     // the AST_SymbolDeclaration that it points to).
     var lname = -1;
     var to_mangle = [];
+
+    if (options.cache) {
+        this.globals.each(function(symbol){
+            if (options.except.indexOf(symbol.name) < 0) {
+                to_mangle.push(symbol);
+            }
+        });
+    }
+
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_LabeledStatement) {
             // lname is incremented when we get to the AST_Label
@@ -371,12 +532,13 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             return true;        // don't descend again in TreeWalker
         }
         if (node instanceof AST_Scope) {
-            var p = tw.parent();
+            var p = tw.parent(), a = [];
             node.variables.each(function(symbol){
                 if (options.except.indexOf(symbol.name) < 0) {
-                    to_mangle.push(symbol);
+                    a.push(symbol);
                 }
             });
+            to_mangle.push.apply(to_mangle, a);
             return;
         }
         if (node instanceof AST_Label) {
@@ -385,9 +547,23 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             node.mangled_name = name;
             return true;
         }
+        var mangle_with_block_scope =
+            (options.screw_ie8 && node instanceof AST_SymbolCatch) ||
+            node instanceof AST_SymbolBlockDeclaration;
+        if (mangle_with_block_scope) {
+            to_mangle.push(node.definition());
+            return;
+        }
     });
     this.walk(tw);
-    to_mangle.forEach(function(def){ def.mangle(options) });
+    to_mangle.forEach(function(def){
+        if (def.destructuring && !def.destructuring.is_array) return;
+        def.mangle(options);
+    });
+
+    if (options.cache) {
+        options.cache.cname = this.cname;
+    }
 });
 
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
@@ -434,21 +610,27 @@ AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
         else if (node instanceof AST_With)
             base54.consider("with");
         else if (node instanceof AST_ObjectSetter)
-            base54.consider("set" + node.key);
+            base54.consider("set" + (typeof node.key === "string" ? node.key : ""));
         else if (node instanceof AST_ObjectGetter)
-            base54.consider("get" + node.key);
-        else if (node instanceof AST_ObjectKeyVal)
+            base54.consider("get" + (typeof node.key === "string" ? node.key : ""));
+        else if (node instanceof AST_ObjectKeyVal && typeof node.key === "string")
+            base54.consider(node.key);
+        else if (node instanceof AST_ConciseMethod && typeof node.key === "string")
             base54.consider(node.key);
         else if (node instanceof AST_New)
             base54.consider("new");
         else if (node instanceof AST_This)
             base54.consider("this");
+        else if (node instanceof AST_Super)
+            base54.consider("super");
         else if (node instanceof AST_Try)
             base54.consider("try");
         else if (node instanceof AST_Catch)
             base54.consider("catch");
         else if (node instanceof AST_Finally)
             base54.consider("finally");
+        else if (node instanceof AST_Yield)
+            base54.consider("yield");
         else if (node instanceof AST_Symbol && node.unmangleable(options))
             base54.consider(node.name);
         else if (node instanceof AST_Unary || node instanceof AST_Binary)
@@ -487,7 +669,9 @@ var base54 = (function() {
     base54.freq = function(){ return frequency };
     function base54(num) {
         var ret = "", base = 54;
+        num++;
         do {
+            num--;
             ret += String.fromCharCode(chars[num % base]);
             num = Math.floor(num / base);
             base = 64;
@@ -548,6 +732,7 @@ AST_Toplevel.DEFMETHOD("scope_warnings", function(options){
         }
         if (options.unreferenced
             && (node instanceof AST_SymbolDeclaration || node instanceof AST_Label)
+            && !(node instanceof AST_SymbolCatch)
             && node.unreferenced()) {
             AST_Node.warn("{type} {name} is declared but not referenced [{file}:{line},{col}]", {
                 type: node instanceof AST_Label ? "Label" : "Symbol",

lib/sourcemap.js

@@ -49,26 +49,42 @@ function SourceMap(options) {
         file : null,
         root : null,
         orig : null,
+
+        orig_line_diff : 0,
+        dest_line_diff : 0,
     });
     var generator = new MOZ_SourceMap.SourceMapGenerator({
         file       : options.file,
         sourceRoot : options.root
     });
     var orig_map = options.orig && new MOZ_SourceMap.SourceMapConsumer(options.orig);
+
+    if (orig_map && Array.isArray(options.orig.sources)) {
+        orig_map._sources.toArray().forEach(function(source) {
+            var sourceContent = orig_map.sourceContentFor(source, true);
+            if (sourceContent) {
+                generator.setSourceContent(source, sourceContent);
+            }
+        });
+    }
+
     function add(source, gen_line, gen_col, orig_line, orig_col, name) {
         if (orig_map) {
             var info = orig_map.originalPositionFor({
                 line: orig_line,
                 column: orig_col
             });
+            if (info.source === null) {
+                return;
+            }
             source = info.source;
             orig_line = info.line;
             orig_col = info.column;
-            name = info.name;
+            name = info.name || name;
         }
         generator.addMapping({
-            generated : { line: gen_line, column: gen_col },
-            original  : { line: orig_line, column: orig_col },
+            generated : { line: gen_line + options.dest_line_diff, column: gen_col },
+            original  : { line: orig_line + options.orig_line_diff, column: orig_col },
             source    : source,
             name      : name
         });
@@ -76,6 +92,6 @@ function SourceMap(options) {
     return {
         add        : add,
         get        : function() { return generator },
-        toString   : function() { return generator.toString() }
+        toString   : function() { return JSON.stringify(generator.toJSON()); }
     };
 };

lib/transform.js

@@ -44,7 +44,6 @@
 "use strict";
 
 // Tree transformer helpers.
-// XXX: eventually I should refactor the compressor to use this infrastructure.
 
 function TreeTransformer(before, after) {
     TreeWalker.call(this);
@@ -65,13 +64,13 @@ TreeTransformer.prototype = new TreeWalker;
                     x = this;
                     descend(x, tw);
                 } else {
-                    tw.stack[tw.stack.length - 1] = x = this.clone();
+                    tw.stack[tw.stack.length - 1] = x = this;
                     descend(x, tw);
                     y = tw.after(x, in_list);
                     if (y !== undefined) x = y;
                 }
             }
-            tw.pop();
+            tw.pop(this);
             return x;
         });
     };
@@ -160,13 +159,22 @@ TreeTransformer.prototype = new TreeWalker;
     });
 
     _(AST_VarDef, function(self, tw){
+        self.name = self.name.transform(tw);
         if (self.value) self.value = self.value.transform(tw);
     });
 
+    _(AST_Destructuring, function(self, tw) {
+        self.names = do_list(self.names, tw);
+    });
+
     _(AST_Lambda, function(self, tw){
         if (self.name) self.name = self.name.transform(tw);
         self.argnames = do_list(self.argnames, tw);
-        self.body = do_list(self.body, tw);
+        if (self.body instanceof AST_Node) {
+            self.body = self.body.transform(tw);
+        } else {
+            self.body = do_list(self.body, tw);
+        }
     });
 
     _(AST_Call, function(self, tw){
@@ -188,6 +196,10 @@ TreeTransformer.prototype = new TreeWalker;
         self.property = self.property.transform(tw);
     });
 
+    _(AST_Yield, function(self, tw){
+        if (self.expression) self.expression = self.expression.transform(tw);
+    });
+
     _(AST_Unary, function(self, tw){
         self.expression = self.expression.transform(tw);
     });
@@ -212,7 +224,32 @@ TreeTransformer.prototype = new TreeWalker;
     });
 
     _(AST_ObjectProperty, function(self, tw){
+        if (self.key instanceof AST_Node) {
+            self.key = self.key.transform(tw);
+        }
         self.value = self.value.transform(tw);
     });
 
+    _(AST_Class, function(self, tw){
+        if (self.name) self.name = self.name.transform(tw);
+        if (self.extends) self.extends = self.extends.transform(tw);
+        self.properties = do_list(self.properties, tw);
+    });
+
+    _(AST_Expansion, function(self, tw){
+        self.expression = self.expression.transform(tw);
+    });
+
+    _(AST_TemplateString, function(self, tw) {
+        for (var i = 0; i < self.segments.length; i++) {
+            if (!(self.segments[i] instanceof AST_TemplateSegment)) {
+                self.segments[i] = self.segments[i].transform(tw);
+            }
+        }
+    });
+
+    _(AST_PrefixedTemplateString, function(self, tw) {
+        self.template_string = self.template_string.transform(tw);
+    });
+
 })();

lib/utils.js

@@ -59,10 +59,7 @@ function characters(str) {
 };
 
 function member(name, array) {
-    for (var i = array.length; --i >= 0;)
-        if (array[i] == name)
-            return true;
-    return false;
+    return array.indexOf(name) >= 0;
 };
 
 function find_if(func, array) {
@@ -81,31 +78,59 @@ function repeat_string(str, i) {
     return d;
 };
 
+function configure_error_stack(fn) {
+    Object.defineProperty(fn.prototype, "stack", {
+        get: function() {
+            var err = new Error(this.message);
+            err.name = this.name;
+            try {
+                throw err;
+            } catch(e) {
+                return e.stack;
+            }
+        }
+    });
+}
+
 function DefaultsError(msg, defs) {
-    this.msg = msg;
+    this.message = msg;
     this.defs = defs;
 };
+DefaultsError.prototype = Object.create(Error.prototype);
+DefaultsError.prototype.constructor = DefaultsError;
+DefaultsError.prototype.name = "DefaultsError";
+configure_error_stack(DefaultsError);
+
+DefaultsError.croak = function(msg, defs) {
+    throw new DefaultsError(msg, defs);
+};
 
 function defaults(args, defs, croak) {
     if (args === true)
         args = {};
     var ret = args || {};
-    if (croak) for (var i in ret) if (ret.hasOwnProperty(i) && !defs.hasOwnProperty(i))
-        throw new DefaultsError("`" + i + "` is not a supported option", defs);
-    for (var i in defs) if (defs.hasOwnProperty(i)) {
-        ret[i] = (args && args.hasOwnProperty(i)) ? args[i] : defs[i];
+    if (croak) for (var i in ret) if (HOP(ret, i) && !HOP(defs, i))
+        DefaultsError.croak("`" + i + "` is not a supported option", defs);
+    for (var i in defs) if (HOP(defs, i)) {
+        ret[i] = (args && HOP(args, i)) ? args[i] : defs[i];
     }
     return ret;
 };
 
 function merge(obj, ext) {
-    for (var i in ext) if (ext.hasOwnProperty(i)) {
+    var count = 0;
+    for (var i in ext) if (HOP(ext, i)) {
         obj[i] = ext[i];
+        count++;
     }
-    return obj;
+    return count;
 };
 
-function noop() {};
+function noop() {}
+function return_false() { return false; }
+function return_true() { return true; }
+function return_this() { return this; }
+function return_null() { return null; }
 
 var MAP = (function(){
     function MAP(a, f, backwards) {
@@ -141,7 +166,7 @@ var MAP = (function(){
             }
         }
         else {
-            for (i in a) if (a.hasOwnProperty(i)) if (doit()) break;
+            for (i in a) if (HOP(a, i)) if (doit()) break;
         }
         return top.concat(ret);
     };
@@ -162,7 +187,7 @@ function push_uniq(array, el) {
 
 function string_template(text, props) {
     return text.replace(/\{(.+?)\}/g, function(str, p){
-        return props[p];
+        return props && props[p];
     });
 };
 
@@ -221,10 +246,19 @@ function makePredicate(words) {
             }
         cats.push([words[i]]);
     }
+    function quote(word) {
+        return JSON.stringify(word).replace(/[\u2028\u2029]/g, function(s) {
+            switch (s) {
+                case "\u2028": return "\\u2028";
+                case "\u2029": return "\\u2029";
+            }
+            return s;
+        });
+    }
     function compareTo(arr) {
-        if (arr.length == 1) return f += "return str === " + JSON.stringify(arr[0]) + ";";
+        if (arr.length == 1) return f += "return str === " + quote(arr[0]) + ";";
         f += "switch(str){";
-        for (var i = 0; i < arr.length; ++i) f += "case " + JSON.stringify(arr[i]) + ":";
+        for (var i = 0; i < arr.length; ++i) f += "case " + quote(arr[i]) + ":";
         f += "return true}return false;";
     }
     // When there are more than three length categories, an outer
@@ -245,6 +279,13 @@ function makePredicate(words) {
     return new Function("str", f);
 };
 
+function all(array, predicate) {
+    for (var i = array.length; --i >= 0;)
+        if (!predicate(array[i]))
+            return false;
+    return true;
+};
+
 function Dictionary() {
     this._values = Object.create(null);
     this._size = 0;
@@ -255,6 +296,14 @@ Dictionary.prototype = {
         this._values["$" + key] = val;
         return this;
     },
+    add: function(key, val) {
+        if (this.has(key)) {
+            this.get(key).push(val);
+        } else {
+            this.set(key, [ val ]);
+        }
+        return this;
+    },
     get: function(key) { return this._values["$" + key] },
     del: function(key) {
         if (this.has(key)) {
@@ -276,5 +325,38 @@ Dictionary.prototype = {
         for (var i in this._values)
             ret.push(f(this._values[i], i.substr(1)));
         return ret;
-    }
+    },
+    toObject: function() { return this._values }
 };
+Dictionary.fromObject = function(obj) {
+    var dict = new Dictionary();
+    dict._size = merge(dict._values, obj);
+    return dict;
+};
+
+function HOP(obj, prop) {
+    return Object.prototype.hasOwnProperty.call(obj, prop);
+}
+
+// return true if the node at the top of the stack (that means the
+// innermost node in the current output) is lexically the first in
+// a statement.
+function first_in_statement(stack) {
+    var node = stack.parent(-1);
+    for (var i = 0, p; p = stack.parent(i); i++) {
+        if (p instanceof AST_Statement && p.body === node)
+            return true;
+        if ((p instanceof AST_Seq           && p.car === node        ) ||
+            (p instanceof AST_Call          && p.expression === node && !(p instanceof AST_New) ) ||
+            (p instanceof AST_Dot           && p.expression === node ) ||
+            (p instanceof AST_Sub           && p.expression === node ) ||
+            (p instanceof AST_Conditional   && p.condition === node  ) ||
+            (p instanceof AST_Binary        && p.left === node       ) ||
+            (p instanceof AST_UnaryPostfix  && p.expression === node ))
+        {
+            node = p;
+        } else {
+            return false;
+        }
+    }
+}

package.json

@@ -1,25 +1,54 @@
 {
-    "name": "uglify-js",
-    "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-    "homepage": "http://lisperator.net/uglifyjs",
-    "main": "tools/node.js",
-    "version": "2.2.1",
-    "engines": { "node" : ">=0.4.0" },
-    "maintainers": [{
-        "name": "Mihai Bazon",
-        "email": "mihai.bazon@gmail.com",
-        "web": "http://lisperator.net/"
-    }],
-    "repositories": [{
-        "type": "git",
-        "url": "https://github.com/mishoo/UglifyJS2.git"
-    }],
-    "dependencies": {
-        "source-map" : "~0.1.7",
-        "optimist"   : "~0.3.5"
-    },
-    "bin": {
-        "uglifyjs" : "bin/uglifyjs"
-    },
-    "scripts": {"test": "node test/run-tests.js"}
+  "name": "uglify-js",
+  "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
+  "homepage": "http://lisperator.net/uglifyjs",
+  "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
+  "license": "BSD-2-Clause",
+  "version": "2.8.17",
+  "engines": {
+    "node": ">=0.8.0"
+  },
+  "maintainers": [
+    "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)"
+  ],
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/mishoo/UglifyJS2.git"
+  },
+  "bugs": {
+    "url": "https://github.com/mishoo/UglifyJS2/issues"
+  },
+  "main": "tools/node.js",
+  "bin": {
+    "uglifyjs": "bin/uglifyjs"
+  },
+  "files": [
+    "bin",
+    "lib",
+    "tools",
+    "LICENSE"
+  ],
+  "dependencies": {
+    "source-map": "~0.5.1",
+    "yargs": "~3.10.0"
+  },
+  "devDependencies": {
+    "acorn": "~0.6.0",
+    "escodegen": "~1.3.3",
+    "esfuzz": "~0.3.1",
+    "estraverse": "~1.5.1",
+    "mocha": "~2.3.4"
+  },
+  "optionalDependencies": {
+    "uglify-to-browserify": "~1.0.0"
+  },
+  "browserify": {
+    "transform": [
+      "uglify-to-browserify"
+    ]
+  },
+  "scripts": {
+    "test": "node test/run-tests.js"
+  },
+  "keywords": ["uglify", "uglify-js", "minify", "minifier"]
 }

test/benchmark.js

@@ -0,0 +1,80 @@
+#! /usr/bin/env node
+// -*- js -*-
+
+"use strict";
+
+var createHash = require("crypto").createHash;
+var fork = require("child_process").fork;
+var args = process.argv.slice(2);
+if (!args.length) {
+    args.push("-mc", "warnings=false");
+}
+args.push("--stats");
+var urls = [
+    "https://code.jquery.com/jquery-3.1.1.js",
+    "https://code.angularjs.org/1.6.1/angular.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/mathjs/3.9.0/math.js",
+    "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.js",
+    "https://unpkg.com/react@15.3.2/dist/react.js",
+    "http://builds.emberjs.com/tags/v2.11.0/ember.prod.js",
+    "https://cdn.jsdelivr.net/lodash/4.17.4/lodash.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/d3/4.5.0/d3.js",
+];
+var results = {};
+var remaining = 2 * urls.length;
+function done() {
+    if (!--remaining) {
+        var failures = [];
+        urls.forEach(function(url) {
+            var info = results[url];
+            console.log();
+            console.log(url);
+            console.log(info.log);
+            var elapsed = 0;
+            info.log.replace(/: ([0-9]+\.[0-9]{3})s/g, function(match, time) {
+                elapsed += parseFloat(time);
+            });
+            console.log("Run-time:", elapsed.toFixed(3), "s");
+            console.log("Original:", info.input, "bytes");
+            console.log("Uglified:", info.output, "bytes");
+            console.log("SHA1 sum:", info.sha1);
+            if (info.code) {
+                failures.push(url);
+            }
+        });
+        if (failures.length) {
+            console.error("Benchmark failed:");
+            failures.forEach(function(url) {
+                console.error(url);
+            });
+            process.exit(1);
+        }
+    }
+}
+urls.forEach(function(url) {
+    results[url] = {
+        input: 0,
+        output: 0,
+        log: ""
+    };
+    require(url.slice(0, url.indexOf(":"))).get(url, function(res) {
+        var uglifyjs = fork("bin/uglifyjs", args, { silent: true });
+        res.on("data", function(data) {
+            results[url].input += data.length;
+        }).pipe(uglifyjs.stdin);
+        uglifyjs.stdout.on("data", function(data) {
+            results[url].output += data.length;
+        }).pipe(createHash("sha1")).on("data", function(data) {
+            results[url].sha1 = data.toString("hex");
+            done();
+        });
+        uglifyjs.stderr.setEncoding("utf8");
+        uglifyjs.stderr.on("data", function(data) {
+            results[url].log += data;
+        });
+        uglifyjs.on("exit", function(code) {
+            results[url].code = code;
+            done();
+        });
+    });
+});

test/compress/angular-inject.js

@@ -0,0 +1,67 @@
+ng_inject_defun: {
+    options = {
+        angular: true
+    };
+    input: {
+        /*@ngInject*/
+        function Controller(dependency) {
+            return dependency;
+        }
+    }
+    expect: {
+        function Controller(dependency) {
+            return dependency;
+        }
+        Controller.$inject=['dependency']
+    }
+}
+
+ng_inject_assignment: {
+    options = {
+        angular: true
+    };
+    input: {
+        /*@ngInject*/
+        var Controller = function(dependency) {
+            return dependency;
+        }
+    }
+    expect: {
+        var Controller = function(dependency) {
+            return dependency;
+        }
+        Controller.$inject=['dependency']
+    }
+}
+
+ng_inject_inline: {
+    options = {
+        angular: true
+    };
+    input: {
+        angular.module('a').
+            factory('b',
+                /*@ngInject*/
+                function(dependency) {
+                    return dependency;
+                }).
+            directive('c',
+                /*@ngInject*/
+                function(anotherDependency) {
+                    return anotherDependency;
+                })
+    }
+    expect: {
+        angular.module('a').
+            factory('b',[
+                'dependency',
+                function(dependency) {
+                    return dependency;
+                }]).
+            directive('c',[
+                'anotherDependency',
+                function(anotherDependency) {
+                    return anotherDependency;
+                }])
+    }
+}

test/compress/arrays.js

@@ -0,0 +1,252 @@
+// NOTE trailing comma doesn't contribute to length of an array
+// That also means the array changes length if previous element is a hole too and got cut off
+holes_and_undefined: {
+    input: {
+        w = [1,,];
+        x = [1, 2, undefined];
+        y = [1, , 2, ];
+        z = [1, undefined, 3];
+    }
+    expect: {
+        w=[1,,];
+        x=[1,2,void 0];
+        y=[1,,2];
+        z=[1,void 0,3];
+    }
+}
+
+constant_join: {
+    options = {
+        unsafe   : true,
+        evaluate : true
+    };
+    input: {
+        var a = [ "foo", "bar", "baz" ].join("");
+        var a1 = [ "foo", "bar", "baz" ].join();
+        var a2 = [ "foo", "bar", "baz" ].join(null);
+        var a3 = [ "foo", "bar", "baz" ].join(void 0);
+        var a4 = [ "foo", , "baz" ].join();
+        var a5 = [ "foo", null, "baz" ].join();
+        var a6 = [ "foo", void 0, "baz" ].join();
+        var b = [ "foo", 1, 2, 3, "bar" ].join("");
+        var c = [ boo(), "foo", 1, 2, 3, "bar", bar() ].join("");
+        var c1 = [ boo(), bar(), "foo", 1, 2, 3, "bar", bar() ].join("");
+        var c2 = [ 1, 2, "foo", "bar", baz() ].join("");
+        var c3 = [ boo() + bar() + "foo", 1, 2, 3, "bar", bar() + "foo" ].join("");
+        var c4 = [ 1, 2, null, undefined, "foo", "bar", baz() ].join("");
+        var c5 = [ boo() + bar() + "foo", 1, 2, 3, "bar", bar() + "foo" ].join();
+        var c6 = [ 1, 2, null, undefined, "foo", "bar", baz() ].join();
+        var d = [ "foo", 1 + 2 + "bar", "baz" ].join("-");
+        var e = [].join(foo + bar);
+        var f = [].join("");
+        var g = [].join("foo");
+    }
+    expect: {
+        var a = "foobarbaz";
+        var a1 = "foo,bar,baz";
+        var a2 = "foonullbarnullbaz";
+        var a3 = "foo,bar,baz";
+        var a4 = "foo,,baz";
+        var a5 = "foo,,baz";
+        var a6 = "foo,,baz";
+        var b = "foo123bar";
+        var c = boo() + "foo123bar" + bar();
+        var c1 = "" + boo() + bar() + "foo123bar" + bar();
+        var c2 = "12foobar" + baz();
+        var c3 = boo() + bar() + "foo123bar" + bar() + "foo";
+        var c4 = "12foobar" + baz();
+        var c5 = [ boo() + bar() + "foo", 1, 2, 3, "bar", bar() + "foo" ].join();
+        var c6 = [ "1,2,,,foo,bar", baz() ].join();
+        var d = "foo-3bar-baz";
+        var e = [].join(foo + bar);
+        var f = "";
+        var g = "";
+    }
+}
+
+constant_join_2: {
+    options = {
+        unsafe   : true,
+        evaluate : true
+    };
+    input: {
+        var a = [ "foo", "bar", boo(), "baz", "x", "y" ].join("");
+        var b = [ "foo", "bar", boo(), "baz", "x", "y" ].join("-");
+        var c = [ "foo", "bar", boo(), "baz", "x", "y" ].join("really-long-separator");
+        var d = [ "foo", "bar", boo(),
+                  [ "foo", 1, 2, 3, "bar" ].join("+"),
+                  "baz", "x", "y" ].join("-");
+        var e = [ "foo", "bar", boo(),
+                  [ "foo", 1, 2, 3, "bar" ].join("+"),
+                  "baz", "x", "y" ].join("really-long-separator");
+        var f = [ "str", "str" + variable, "foo", "bar", "moo" + foo ].join("");
+    }
+    expect: {
+        var a = "foobar" + boo() + "bazxy";
+        var b = [ "foo-bar", boo(), "baz-x-y" ].join("-");
+        var c = [ "foo", "bar", boo(), "baz", "x", "y" ].join("really-long-separator");
+        var d = [ "foo-bar", boo(), "foo+1+2+3+bar-baz-x-y" ].join("-");
+        var e = [ "foo", "bar", boo(),
+                  "foo+1+2+3+bar",
+                  "baz", "x", "y" ].join("really-long-separator");
+        var f = "strstr" + variable + "foobarmoo" + foo;
+    }
+}
+
+spread_with_variable_as_last_element: {
+    input: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values];
+    }
+    expect: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values];
+    }
+}
+
+spread_with_variable_in_middle: {
+    input: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values, 7,,,];
+    }
+    expect: {
+        var values = [4, 5, 6];
+        var a = [1, 2, 3, ...values, 7,,,];
+    }
+}
+
+spread_with_variable_at_front: {
+    input: {
+        var values = [1, 2, 3];
+        var a = [...values, 4, 5, 6];
+    }
+    expect: {
+        var values = [1, 2, 3];
+        var a = [...values, 4, 5, 6];
+    }
+}
+
+spread_with_variable_at_front_after_elisions: {
+    input: {
+        var values = [1, 2, 3];
+        var a = [,,,...values, 4, 5, 6];
+    }
+    expect: {
+        var values = [1, 2, 3];
+        var a = [,,,...values, 4, 5, 6];
+    }
+}
+
+spread_with_array_at_end: {
+    input: {
+        var a = [1, 2, ...[4, 5, 6]];
+    }
+    expect: {
+        var a = [1, 2, ...[4, 5, 6]];
+    }
+}
+
+spread_with_logical_expression_at_end: {
+    options = { evaluate: true }
+    input: {
+        var a = [1, 2, 3, ...[2+2]]
+    }
+    expect: {
+        var a = [1, 2, 3, ...[4]]
+    }
+}
+
+spread_with_logical_expression_at_middle: {
+    options = { evaluate: true }
+    input: {
+        var a = [1, 1, ...[1+1, 1+2, 2+3], 8]
+    }
+    expect: {
+        var a = [1, 1, ...[2, 3, 5], 8]
+    }
+}
+
+constant_join_3: {
+    options = {
+        unsafe: true,
+        evaluate: true,
+    };
+    input: {
+        var a = [ null ].join();
+        var b = [ , ].join();
+        var c = [ , 1, , 3 ].join();
+        var d = [ foo ].join();
+        var e = [ foo, null, undefined, bar ].join("-");
+        var f = [ foo, bar ].join("");
+        var g = [ null, "foo", null, bar + "baz" ].join("");
+        var h = [ null, "foo", null, bar + "baz" ].join("-");
+        var i = [ "foo" + bar, null, baz + "moo" ].join("");
+        var j = [ foo + "bar", baz ].join("");
+        var k = [ foo, "bar" + baz ].join("");
+        var l = [ foo, bar + "baz" ].join("");
+    }
+    expect: {
+        var a = "";
+        var b = "";
+        var c = ",1,,3";
+        var d = "" + foo;
+        var e = [ foo, "-", bar ].join("-");
+        var f = "" + foo + bar;
+        var g = "foo" + bar + "baz";
+        var h = [ "-foo-", bar + "baz" ].join("-");
+        var i = "foo" + bar + baz + "moo";
+        var j = foo + "bar" + baz;
+        var k = foo + "bar" + baz;
+        var l = foo + (bar + "baz");
+    }
+}
+
+for_loop: {
+    options = {
+        unsafe      : true,
+        unused      : true,
+        evaluate    : true,
+        reduce_vars : true
+    };
+    input: {
+        function f0() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++) {
+                console.log(a[i]);
+            }
+        }
+
+        function f1() {
+            var a = [1, 2, 3];
+            for (var i = 0, len = a.length; i < len; i++) {
+                console.log(a[i]);
+            }
+        }
+
+        function f2() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++) {
+                a[i]++;
+            }
+        }
+    }
+    expect: {
+        function f0() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < 3; i++)
+                console.log(a[i]);
+        }
+
+        function f1() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < 3; i++)
+                console.log(a[i]);
+        }
+
+        function f2() {
+            var a = [1, 2, 3];
+            for (var i = 0; i < a.length; i++)
+                a[i]++;
+        }
+    }
+}

test/compress/arrow.js

@@ -0,0 +1,137 @@
+arrow_functions_without_body: {
+    input: {
+        var a1 = () => 42;
+        var a2 = (p) => p;
+        var a3 = p => p;
+        var a4 = (...p) => p;
+        var a5 = (b, c) => b + c;
+        var a6 = (b, ...c) => b + c[0];
+        var a7 = (...b) => b.join();
+    }
+    expect: {
+        var a1 = () => 42;
+        var a2 = (p) => p;
+        var a3 = p => p;
+        var a4 = (...p) => p;
+        var a5 = (b, c) => b + c;
+        var a6 = (b, ...c) => b + c[0];
+        var a7 = (...b) => b.join();
+    }
+}
+
+arrow_functions_with_body: {
+    input: {
+        var a1 = () => {
+            var a = 42 * Math.random();
+            return a;
+        };
+        var a2 = (p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a3 = p => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a4 = (...p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a5 = (b, c) => {
+            var result = b * c + b / c;
+            return result
+        };
+        var a6 = (b, ...c) => {
+            var result = b;
+            for (var i = 0; i < c.length; i++)
+                result += c[i];
+            return result
+        };
+        var a7 = (...b) => {
+            b.join();
+        }
+    }
+    expect: {
+        var a1 = () => {
+            var a = 42 * Math.random();
+            return a;
+        };
+        var a2 = (p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a3 = p => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a4 = (...p) => {
+            var a = Math.random() * p;
+            return a;
+        };
+        var a5 = (b, c) => {
+            var result = b * c + b / c;
+            return result
+        };
+        var a6 = (b, ...c) => {
+            var result = b;
+            for (var i = 0; i < c.length; i++)
+                result += c[i];
+            return result
+        };
+        var a7 = (...b) => {
+            b.join();
+        };
+    }
+}
+
+arrow_function_with_single_parameter_with_default: {
+    input: {
+        var foo = (a = 0) => doSomething(a);
+    }
+    expect_exact: "var foo=(a=0)=>doSomething(a);"
+}
+
+arrow_binding_pattern: {
+    input: {
+        var foo = ([]) => "foo";
+        var bar = ({}) => "bar";
+        var with_default = (foo = "default") => foo;
+        var object_with_default = ({foo = "default", bar: baz = "default"}) => foo;
+        var array_after_spread = (...[foo]) => foo;
+        var array_after_spread = (...{foo}) => foo;
+        var computed = ({ [compute()]: x }) => {};
+        var array_hole = ([, , ...x] = [1, 2]) => {};
+        var object_trailing_elision = ({foo,}) => {};
+        var spread_empty_array = (...[]) => "foo";
+        var spread_empty_object = (...{}) => "foo";
+    }
+    expect: {
+        var foo = ([]) => "foo";
+        var bar = ({}) => "bar";
+        var with_default = (foo = "default") => foo;
+        var object_with_default = ({foo = "default", bar: baz = "default"}) => foo;
+        var array_after_spread = (...[foo]) => foo;
+        var array_after_spread = (...{foo}) => foo;
+        var computed = ({ [compute()]: x }) => {};
+        var array_hole = ([, , ...x] = [1, 2]) => {};
+        var object_trailing_elision = ({foo,}) => {};
+        var spread_empty_array = (...[]) => "foo";
+        var spread_empty_object = (...{}) => "foo";
+    }
+}
+
+arrow_binding_pattern_strict: {
+    input: {
+        var foo = ([,]) => "foo";
+    }
+    expect_exact: 'var foo=([,])=>"foo";'
+}
+
+arrow_with_regexp: {
+    input: {
+        num => /\d{11,14}/.test( num )
+    }
+    expect: {
+        num => /\d{11,14}/.test( num )
+    }
+}

test/compress/ascii.js

@@ -0,0 +1,36 @@
+ascii_only_true: {
+    options = {}
+    beautify = {
+        ascii_only : true,
+        screw_ie8  : true,
+        beautify   : false,
+    }
+    input: {
+        function f() {
+            return "\x000\x001\x007\x008\x00" +
+                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
+                   "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
+        }
+    }
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
+}
+
+ascii_only_false: {
+    options = {}
+    beautify = {
+        ascii_only : false,
+        screw_ie8  : true,
+        beautify   : false,
+    }
+    input: {
+        function f() {
+            return "\x000\x001\x007\x008\x00" +
+                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
+                   "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
+        }
+    }
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
+}
+

test/compress/asm.js

@@ -0,0 +1,106 @@
+asm_mixed: {
+    options = {
+        sequences     : true,
+        properties    : true,
+        dead_code     : true,
+        drop_debugger : true,
+        conditionals  : true,
+        comparisons   : true,
+        evaluate      : true,
+        booleans      : true,
+        loops         : true,
+        unused        : true,
+        hoist_funs    : true,
+        keep_fargs    : true,
+        keep_fnames   : false,
+        hoist_vars    : true,
+        if_return     : true,
+        join_vars     : true,
+        cascade       : true,
+        side_effects  : true,
+        negate_iife   : true
+    };
+    input: {
+        // adapted from http://asmjs.org/spec/latest/
+        function asm_GeometricMean(stdlib, foreign, buffer) {
+          "use asm";
+          var exp = stdlib.Math.exp;
+          var log = stdlib.Math.log;
+          var values = new stdlib.Float64Array(buffer);
+          function logSum(start, end) {
+            start = start|0;
+            end = end|0;
+            var sum = 0.0, p = 0, q = 0;
+            // asm.js forces byte addressing of the heap by requiring shifting by 3
+            for (p = start << 3, q = end << 3; (p|0) < (q|0); p = (p + 8)|0) {
+              sum = sum + +log(values[p>>3]);
+            }
+            return +sum;
+          }
+          function geometricMean(start, end) {
+            start = start|0;
+            end = end|0;
+            return +exp(+logSum(start, end) / +((end - start)|0));
+          }
+          return { geometricMean: geometricMean };
+        }
+        function no_asm_GeometricMean(stdlib, foreign, buffer) {
+          var exp = stdlib.Math.exp;
+          var log = stdlib.Math.log;
+          var values = new stdlib.Float64Array(buffer);
+          function logSum(start, end) {
+            start = start|0;
+            end = end|0;
+            var sum = 0.0, p = 0, q = 0;
+            // asm.js forces byte addressing of the heap by requiring shifting by 3
+            for (p = start << 3, q = end << 3; (p|0) < (q|0); p = (p + 8)|0) {
+              sum = sum + +log(values[p>>3]);
+            }
+            return +sum;
+          }
+          function geometricMean(start, end) {
+            start = start|0;
+            end = end|0;
+            return +exp(+logSum(start, end) / +((end - start)|0));
+          }
+          return { geometricMean: geometricMean };
+        }
+    }
+    expect: {
+        function asm_GeometricMean(stdlib, foreign, buffer) {
+            "use asm";
+            var exp = stdlib.Math.exp;
+            var log = stdlib.Math.log;
+            var values = new stdlib.Float64Array(buffer);
+            function logSum(start, end) {
+                start = start | 0;
+                end = end | 0;
+                var sum = 0.0, p = 0, q = 0;
+                for (p = start << 3, q = end << 3; (p | 0) < (q | 0); p = p + 8 | 0) {
+                    sum = sum + +log(values[p >> 3]);
+                }
+                return +sum;
+            }
+            function geometricMean(start, end) {
+                start = start | 0;
+                end = end | 0;
+                return +exp(+logSum(start, end) / +(end - start | 0));
+            }
+            return { geometricMean: geometricMean };
+        }
+        function no_asm_GeometricMean(stdlib, foreign, buffer) {
+            function logSum(start, end) {
+                start |= 0, end |= 0;
+                var sum = 0, p = 0, q = 0;
+                for (p = start << 3, q = end << 3; (0 | p) < (0 | q); p = p + 8 | 0) sum += +log(values[p >> 3]);
+                return +sum;
+            }
+            function geometricMean(start, end) {
+                return start |= 0, end |= 0, +exp(+logSum(start, end) / +(end - start | 0));
+            }
+            var exp = stdlib.Math.exp, log = stdlib.Math.log, values = new stdlib.Float64Array(buffer);
+            return { geometricMean: geometricMean };
+        }
+    }
+}
+

test/compress/assignment.js

@@ -0,0 +1,238 @@
+op_equals_left_local_var: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var x;
+
+        x = x +   3;
+        x = x -   3;
+        x = x /   3;
+        x = x *   3;
+        x = x >>  3;
+        x = x <<  3;
+        x = x >>> 3;
+        x = x |   3;
+        x = x ^   3;
+        x = x %   3;
+        x = x &   3;
+
+        x = x +   g();
+        x = x -   g();
+        x = x /   g();
+        x = x *   g();
+        x = x >>  g();
+        x = x <<  g();
+        x = x >>> g();
+        x = x |   g();
+        x = x ^   g();
+        x = x %   g();
+        x = x &   g();
+    }
+    expect: {
+        var x;
+
+        x   += 3;
+        x   -= 3;
+        x   /= 3;
+        x   *= 3;
+        x  >>= 3;
+        x  <<= 3;
+        x >>>= 3;
+        x   |= 3;
+        x   ^= 3;
+        x   %= 3;
+        x   &= 3;
+
+        x   += g();
+        x   -= g();
+        x   /= g();
+        x   *= g();
+        x  >>= g();
+        x  <<= g();
+        x >>>= g();
+        x   |= g();
+        x   ^= g();
+        x   %= g();
+        x   &= g();
+    }
+}
+
+op_equals_right_local_var: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var x;
+
+        x = (x -= 2) ^ x;
+
+        x = 3 +   x;
+        x = 3 -   x;
+        x = 3 /   x;
+        x = 3 *   x;
+        x = 3 >>  x;
+        x = 3 <<  x;
+        x = 3 >>> x;
+        x = 3 |   x;
+        x = 3 ^   x;
+        x = 3 %   x;
+        x = 3 &   x;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+    expect: {
+        var x;
+
+        x = (x -= 2) ^ x;
+
+        x = 3 + x;
+        x = 3 - x;
+        x = 3 / x;
+        x *= 3;
+        x = 3 >> x;
+        x = 3 << x;
+        x = 3 >>> x;
+        x |= 3;
+        x ^= 3;
+        x = 3 % x;
+        x &= 3;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+}
+op_equals_left_global_var: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        x = x +   3;
+        x = x -   3;
+        x = x /   3;
+        x = x *   3;
+        x = x >>  3;
+        x = x <<  3;
+        x = x >>> 3;
+        x = x |   3;
+        x = x ^   3;
+        x = x %   3;
+        x = x &   3;
+
+        x = x +   g();
+        x = x -   g();
+        x = x /   g();
+        x = x *   g();
+        x = x >>  g();
+        x = x <<  g();
+        x = x >>> g();
+        x = x |   g();
+        x = x ^   g();
+        x = x %   g();
+        x = x &   g();
+    }
+    expect: {
+        x   += 3;
+        x   -= 3;
+        x   /= 3;
+        x   *= 3;
+        x  >>= 3;
+        x  <<= 3;
+        x >>>= 3;
+        x   |= 3;
+        x   ^= 3;
+        x   %= 3;
+        x   &= 3;
+
+        x   += g();
+        x   -= g();
+        x   /= g();
+        x   *= g();
+        x  >>= g();
+        x  <<= g();
+        x >>>= g();
+        x   |= g();
+        x   ^= g();
+        x   %= g();
+        x   &= g();
+    }
+}
+
+op_equals_right_global_var: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        x = (x -= 2) ^ x;
+
+        x = 3 +   x;
+        x = 3 -   x;
+        x = 3 /   x;
+        x = 3 *   x;
+        x = 3 >>  x;
+        x = 3 <<  x;
+        x = 3 >>> x;
+        x = 3 |   x;
+        x = 3 ^   x;
+        x = 3 %   x;
+        x = 3 &   x;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+    expect: {
+        x = (x -= 2) ^ x;
+
+        x = 3 +   x;
+        x = 3 -   x;
+        x = 3 /   x;
+        x *= 3;
+        x = 3 >>  x;
+        x = 3 <<  x;
+        x = 3 >>> x;
+        x |= 3;
+        x ^= 3;
+        x = 3 %   x;
+        x &= 3;
+
+        x = g() +   x;
+        x = g() -   x;
+        x = g() /   x;
+        x = g() *   x;
+        x = g() >>  x;
+        x = g() <<  x;
+        x = g() >>> x;
+        x = g() |   x;
+        x = g() ^   x;
+        x = g() %   x;
+        x = g() &   x;
+    }
+}

test/compress/block-scope.js

@@ -0,0 +1,177 @@
+
+let_statement: {
+    input: {
+        let x = 6;
+    }
+    expect_exact: "let x=6;"
+}
+
+do_not_hoist_let: {
+    options = {
+        hoist_vars: true,
+    };
+    input: {
+        function x() {
+            if (FOO) {
+                let let1;
+                let let2;
+                var var1;
+                var var2;
+            }
+        }
+    }
+    expect: {
+        function x() {
+            var var1, var2;
+            if (FOO) {
+                let let1;
+                let let2;
+            }
+        }
+    }
+}
+
+do_not_remove_anon_blocks_if_they_have_decls: {
+    input: {
+        function x() {
+            {
+                let x;
+            }
+            {
+                var x;
+            }
+            {
+                const y;
+                class Zee {};
+            }
+        }
+        {
+            let y;
+        }
+        {
+            var y;
+        }
+    }
+    expect: {
+        function x(){
+            {
+                let x
+            }
+            var x;
+            {
+                const y;
+                class Zee {}
+            }
+        }
+        {
+            let y
+        }
+        var y;
+    }
+}
+
+remove_unused_in_global_block: {
+    options = {
+        unused: true,
+    }
+    input: {
+        {
+            let x;
+            const y;
+            class Zee {};
+            var w;
+        }
+        let ex;
+        const why;
+        class Zed {};
+        var wut;
+        console.log(x, y, Zee);
+    }
+    expect: {
+        var w;
+        let ex;
+        const why;
+        class Zed {};
+        var wut;
+        console.log(x, y, Zee);
+    }
+}
+
+regression_block_scope_resolves: {
+    mangle = { };
+    options = {
+        dead_code: false
+    };
+    input: {
+        (function () {
+            if(1) {
+                let x;
+                const y;
+                class Zee {};
+            }
+            if(1) {
+                let ex;
+                const why;
+                class Zi {};
+            }
+            console.log(x, y, Zee, ex, why, Zi);
+        }());
+    }
+    expect: {
+        (function () {
+            if (1) {
+                let o;
+                const n;
+                class c {};
+            }
+            if (1) {
+                let o;
+                const n;
+                class c {};
+            }
+            console.log(x, y, Zee, ex, why, Zi);
+        }());
+    }
+}
+
+switch_block_scope_mangler: {
+    mangle = {}
+    input: {
+        var fn = function(code) {
+            switch (code) {
+                case 1:
+                    let apple = code + 1;
+                    let dog = code + 4;
+                    console.log(apple, dog);
+                    break;
+                case 2:
+                    let banana = code + 2;
+                    console.log(banana);
+                    break;
+                default:
+                    let cat = code + 3;
+                    console.log(cat);
+            }
+        };
+    }
+    expect: {
+        var fn = function(o) {
+            switch (o) {
+              case 1:
+                let e = o + 1
+                let c = o + 4;
+                console.log(e, c);
+                break;
+
+              case 2:
+                let l = o + 2;
+                console.log(l);
+                break;
+
+              default:
+                let a = o + 3;
+                console.log(a);
+            }
+        };
+    }
+}

test/compress/comparing.js

@@ -0,0 +1,76 @@
+keep_comparisons: {
+    options = {
+        comparisons: true,
+        unsafe_comps: false
+    }
+    input: {
+        var obj1 = {
+            valueOf: function() {triggeredFirst();}
+        }
+        var obj2 = {
+            valueOf: function() {triggeredSecond();}
+        }
+        var result1 = obj1 <= obj2;
+        var result2 = obj1 <  obj2;
+        var result3 = obj1 >= obj2;
+        var result4 = obj1 >  obj2;
+    }
+    expect: {
+        var obj1 = {
+            valueOf: function() {triggeredFirst();}
+        }
+        var obj2 = {
+            valueOf: function() {triggeredSecond();}
+        }
+        var result1 = obj1 <= obj2;
+        var result2 = obj1 <  obj2;
+        var result3 = obj1 >= obj2;
+        var result4 = obj1 >  obj2;
+    }
+}
+
+keep_comparisons_with_unsafe_comps: {
+    options = {
+        comparisons: true,
+        unsafe_comps: true
+    }
+    input: {
+        var obj1 = {
+            valueOf: function() {triggeredFirst();}
+        }
+        var obj2 = {
+            valueOf: function() {triggeredSecond();}
+        }
+        var result1 = obj1 <= obj2;
+        var result2 = obj1 <  obj2;
+        var result3 = obj1 >= obj2;
+        var result4 = obj1 >  obj2;
+    }
+    expect: {
+        var obj1 = {
+            valueOf: function() {triggeredFirst();}
+        }
+        var obj2 = {
+            valueOf: function() {triggeredSecond();}
+        }
+        var result1 = obj2 >= obj1;
+        var result2 = obj2 >  obj1;
+        var result3 = obj1 >= obj2;
+        var result4 = obj1 >  obj2;
+    }
+}
+
+dont_change_in_or_instanceof_expressions: {
+    input: {
+        1 in 1;
+        null in null;
+        1 instanceof 1;
+        null instanceof null;
+    }
+    expect: {
+        1 in 1;
+        null in null;
+        1 instanceof 1;
+        null instanceof null;
+    }
+}

test/compress/concat-strings.js

@@ -0,0 +1,223 @@
+concat_1: {
+    options = {
+        evaluate: true
+    };
+    input: {
+        var a = "foo" + "bar" + x() + "moo" + "foo" + y() + "x" + "y" + "z" + q();
+        var b = "foo" + 1 + x() + 2 + "boo";
+        var c = 1 + x() + 2 + "boo";
+
+        // this CAN'T safely be shortened to 1 + x() + "5boo"
+        var d = 1 + x() + 2 + 3 + "boo";
+
+        var e = 1 + x() + 2 + "X" + 3 + "boo";
+
+        // be careful with concatentation with "\0" with octal-looking strings.
+        var f = "\0" + 360 + "\0" + 8 + "\0";
+    }
+    expect: {
+        var a = "foobar" + x() + "moofoo" + y() + "xyz" + q();
+        var b = "foo1" + x() + "2boo";
+        var c = 1 + x() + 2 + "boo";
+        var d = 1 + x() + 2 + 3 + "boo";
+        var e = 1 + x() + 2 + "X3boo";
+        var f = "\x00360\08\0";
+    }
+}
+
+concat_2: {
+    options = {};
+    input: {
+        console.log(
+            1 + (2 + 3),
+            1 + (2 + "3"),
+            1 + ("2" + 3),
+            1 + ("2" + "3"),
+            "1" + (2 + 3),
+            "1" + (2 + "3"),
+            "1" + ("2" + 3),
+            "1" + ("2" + "3")
+        );
+    }
+    expect: {
+        console.log(
+            1 + (2 + 3),
+            1 + (2 + "3"),
+            1 + "2" + 3,
+            1 + "2" + "3",
+            "1" + (2 + 3),
+            "1" + 2 + "3",
+            "1" + "2" + 3,
+            "1" + "2" + "3"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_3: {
+    options = {};
+    input: {
+        console.log(
+            1 + 2 + (3 + 4 + 5),
+            1 + 2 + (3 + 4 + "5"),
+            1 + 2 + (3 + "4" + 5),
+            1 + 2 + (3 + "4" + "5"),
+            1 + 2 + ("3" + 4 + 5),
+            1 + 2 + ("3" + 4 + "5"),
+            1 + 2 + ("3" + "4" + 5),
+            1 + 2 + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            1 + 2 + (3 + 4 + 5),
+            1 + 2 + (3 + 4 + "5"),
+            1 + 2 + (3 + "4") + 5,
+            1 + 2 + (3 + "4") + "5",
+            1 + 2 + "3" + 4 + 5,
+            1 + 2 + "3" + 4 + "5",
+            1 + 2 + "3" + "4" + 5,
+            1 + 2 + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_4: {
+    options = {};
+    input: {
+        console.log(
+            1 + "2" + (3 + 4 + 5),
+            1 + "2" + (3 + 4 + "5"),
+            1 + "2" + (3 + "4" + 5),
+            1 + "2" + (3 + "4" + "5"),
+            1 + "2" + ("3" + 4 + 5),
+            1 + "2" + ("3" + 4 + "5"),
+            1 + "2" + ("3" + "4" + 5),
+            1 + "2" + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            1 + "2" + (3 + 4 + 5),
+            1 + "2" + (3 + 4) + "5",
+            1 + "2" + 3 + "4" + 5,
+            1 + "2" + 3 + "4" + "5",
+            1 + "2" + "3" + 4 + 5,
+            1 + "2" + "3" + 4 + "5",
+            1 + "2" + "3" + "4" + 5,
+            1 + "2" + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_5: {
+    options = {};
+    input: {
+        console.log(
+            "1" + 2 + (3 + 4 + 5),
+            "1" + 2 + (3 + 4 + "5"),
+            "1" + 2 + (3 + "4" + 5),
+            "1" + 2 + (3 + "4" + "5"),
+            "1" + 2 + ("3" + 4 + 5),
+            "1" + 2 + ("3" + 4 + "5"),
+            "1" + 2 + ("3" + "4" + 5),
+            "1" + 2 + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            "1" + 2 + (3 + 4 + 5),
+            "1" + 2 + (3 + 4) + "5",
+            "1" + 2 + 3 + "4" + 5,
+            "1" + 2 + 3 + "4" + "5",
+            "1" + 2 + "3" + 4 + 5,
+            "1" + 2 + "3" + 4 + "5",
+            "1" + 2 + "3" + "4" + 5,
+            "1" + 2 + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_6: {
+    options = {};
+    input: {
+        console.log(
+            "1" + "2" + (3 + 4 + 5),
+            "1" + "2" + (3 + 4 + "5"),
+            "1" + "2" + (3 + "4" + 5),
+            "1" + "2" + (3 + "4" + "5"),
+            "1" + "2" + ("3" + 4 + 5),
+            "1" + "2" + ("3" + 4 + "5"),
+            "1" + "2" + ("3" + "4" + 5),
+            "1" + "2" + ("3" + "4" + "5")
+        );
+    }
+    expect: {
+        console.log(
+            "1" + "2" + (3 + 4 + 5),
+            "1" + "2" + (3 + 4) + "5",
+            "1" + "2" + 3 + "4" + 5,
+            "1" + "2" + 3 + "4" + "5",
+            "1" + "2" + "3" + 4 + 5,
+            "1" + "2" + "3" + 4 + "5",
+            "1" + "2" + "3" + "4" + 5,
+            "1" + "2" + "3" + "4" + "5"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_7: {
+    input: {
+        console.log(
+            "" + 1,
+            "" + "1",
+            "" + 1 + 2,
+            "" + 1 + "2",
+            "" + "1" + 2,
+            "" + "1" + "2",
+            "" + (x += "foo")
+        );
+    }
+    expect: {
+        console.log(
+            "" + 1,
+            "1",
+            "" + 1 + 2,
+            1 + "2",
+            "1" + 2,
+            "1" + "2",
+            x += "foo"
+        );
+    }
+    expect_stdout: true
+}
+
+concat_8: {
+    input: {
+        console.log(
+            1 + "",
+            "1" + "",
+            1 + 2 + "",
+            1 + "2" + "",
+            "1" + 2 + "",
+            "1" + "2" + "",
+            (x += "foo") + ""
+        );
+    }
+    expect: {
+        console.log(
+            1 + "",
+            "1",
+            1 + 2 + "",
+            1 + "2",
+            "1" + 2,
+            "1" + "2",
+            x += "foo"
+        );
+    }
+    expect_stdout: true
+}

test/compress/conditionals.js

@@ -50,9 +50,11 @@ ifs_3_should_warn: {
         conditionals : true,
         dead_code    : true,
         evaluate     : true,
-        booleans     : true
+        booleans     : true,
+        side_effects : true,
     };
     input: {
+        var x, y;
         if (x && !(x + "1") && y) { // 1
             var qq;
             foo();
@@ -68,6 +70,7 @@ ifs_3_should_warn: {
         }
     }
     expect: {
+        var x, y;
         var qq; bar();          // 1
         var jj; foo();          // 2
     }
@@ -84,7 +87,9 @@ ifs_4: {
             x(foo)[10].bar.baz = something_else();
     }
     expect: {
-        x(foo)[10].bar.baz = (foo && bar) ? something() : something_else();
+        foo && bar
+            ? x(foo)[10].bar.baz = something()
+            : x(foo)[10].bar.baz = something_else();
     }
 }
 
@@ -131,13 +136,829 @@ ifs_6: {
         comparisons: true
     };
     input: {
+        var x, y;
         if (!foo && !bar && !baz && !boo) {
             x = 10;
         } else {
             x = 20;
         }
+        if (y) {
+            x[foo] = 10;
+        } else {
+            x[foo] = 20;
+        }
+        if (foo) {
+            x[bar] = 10;
+        } else {
+            x[bar] = 20;
+        }
     }
     expect: {
+        var x, y;
         x = foo || bar || baz || boo ? 20 : 10;
+        x[foo] = y ? 10 : 20;
+        foo ? x[bar] = 10 : x[bar] = 20;
     }
 }
+
+cond_1: {
+    options = {
+        conditionals: true
+    };
+    input: {
+        var do_something; // if undeclared it's assumed to have side-effects
+        if (some_condition()) {
+            do_something(x);
+        } else {
+            do_something(y);
+        }
+        if (some_condition()) {
+            side_effects(x);
+        } else {
+            side_effects(y);
+        }
+    }
+    expect: {
+        var do_something;
+        do_something(some_condition() ? x : y);
+        some_condition() ? side_effects(x) : side_effects(y);
+    }
+}
+
+cond_2: {
+    options = {
+        conditionals: true
+    };
+    input: {
+        var x, FooBar;
+        if (some_condition()) {
+            x = new FooBar(1);
+        } else {
+            x = new FooBar(2);
+        }
+    }
+    expect: {
+        var x, FooBar;
+        x = new FooBar(some_condition() ? 1 : 2);
+    }
+}
+
+cond_3: {
+    options = {
+        conditionals: true
+    };
+    input: {
+        var FooBar;
+        if (some_condition()) {
+            new FooBar(1);
+        } else {
+            FooBar(2);
+        }
+    }
+    expect: {
+        var FooBar;
+        some_condition() ? new FooBar(1) : FooBar(2);
+    }
+}
+
+cond_4: {
+    options = {
+        conditionals: true
+    };
+    input: {
+        var do_something;
+        if (some_condition()) {
+            do_something();
+        } else {
+            do_something();
+        }
+        if (some_condition()) {
+            side_effects();
+        } else {
+            side_effects();
+        }
+    }
+    expect: {
+        var do_something;
+        some_condition(), do_something();
+        some_condition(), side_effects();
+    }
+}
+
+cond_5: {
+    options = {
+        conditionals: true
+    };
+    input: {
+        if (some_condition()) {
+            if (some_other_condition()) {
+                do_something();
+            } else {
+                alternate();
+            }
+        } else {
+            alternate();
+        }
+
+        if (some_condition()) {
+            if (some_other_condition()) {
+                do_something();
+            }
+        }
+    }
+    expect: {
+        some_condition() && some_other_condition() ? do_something() : alternate();
+        some_condition() && some_other_condition() && do_something();
+    }
+}
+
+cond_7: {
+    options = {
+        conditionals: true,
+        evaluate    : true,
+        side_effects: true,
+    };
+    input: {
+        var x, y, z, a, b;
+        // compress these
+        if (y) {
+            x = 1+1;
+        } else {
+            x = 2;
+        }
+
+        if (y) {
+            x = 1+1;
+        } else if (z) {
+            x = 2;
+        } else {
+            x = 3-1;
+        }
+
+        x = y ? 'foo' : 'fo'+'o';
+
+        x = y ? 'foo' : y ? 'foo' : 'fo'+'o';
+
+        // Compress conditions that have side effects
+        if (condition()) {
+            x = 10+10;
+        } else {
+            x = 20;
+        }
+
+        if (z) {
+            x = 'fuji';
+        } else if (condition()) {
+            x = 'fu'+'ji';
+        } else {
+            x = 'fuji';
+        }
+
+        x = condition() ? 'foobar' : 'foo'+'bar';
+
+        // don't compress these
+        x = y ? a : b;
+
+        x = y ? 'foo' : 'fo';
+    }
+    expect: {
+        var x, y, z, a, b;
+        x = 2;
+        x = 2;
+        x = 'foo';
+        x = 'foo';
+        x = (condition(), 20);
+        x = z ? 'fuji' : (condition(), 'fuji');
+        x = (condition(), 'foobar');
+        x = y ? a : b;
+        x = y ? 'foo' : 'fo';
+    }
+}
+
+cond_7_1: {
+    options = {
+        conditionals: true,
+        evaluate    : true
+    };
+    input: {
+        var x;
+        // access to global should be assumed to have side effects
+        if (y) {
+            x = 1+1;
+        } else {
+            x = 2;
+        }
+    }
+    expect: {
+        var x;
+        x = (y, 2);
+    }
+}
+
+cond_8: {
+    options = {
+        conditionals: true,
+        evaluate    : true,
+        booleans    : false
+    };
+    input: {
+        var a;
+        // compress these
+        a = condition ? true : false;
+        a = !condition ? true : false;
+        a = condition() ? true : false;
+
+        a = condition ? !0 : !1;
+        a = !condition ? !null : !2;
+        a = condition() ? !0 : !-3.5;
+
+        if (condition) {
+            a = true;
+        } else {
+            a = false;
+        }
+
+        if (condition) {
+            a = !0;
+        } else {
+            a = !1;
+        }
+
+        a = condition ? false : true;
+        a = !condition ? false : true;
+        a = condition() ? false : true;
+
+        a = condition ? !3 : !0;
+        a = !condition ? !2 : !0;
+        a = condition() ? !1 : !0;
+
+        if (condition) {
+            a = false;
+        } else {
+            a = true;
+        }
+
+        if (condition) {
+            a = !1;
+        } else {
+            a = !0;
+        }
+
+        // don't compress these
+        a = condition ? 1 : false;
+        a = !condition ? true : 0;
+        a = condition ? 1 : 0;
+    }
+    expect: {
+        var a;
+        a = !!condition;
+        a = !condition;
+        a = !!condition();
+
+        a = !!condition;
+        a = !condition;
+        a = !!condition();
+
+        a = !!condition;
+        a = !!condition;
+
+        a = !condition;
+        a = !!condition;
+        a = !condition();
+
+        a = !condition;
+        a = !!condition;
+        a = !condition();
+
+        a = !condition;
+        a = !condition;
+
+        a = !!condition && 1;
+        a = !condition || 0;
+        a = condition ? 1 : 0;
+    }
+}
+
+cond_8b: {
+    options = {
+        conditionals: true,
+        evaluate    : true,
+        booleans    : true
+    };
+    input: {
+        var a;
+        // compress these
+        a = condition ? true : false;
+        a = !condition ? true : false;
+        a = condition() ? true : false;
+
+        a = condition ? !0 : !1;
+        a = !condition ? !null : !2;
+        a = condition() ? !0 : !-3.5;
+
+        if (condition) {
+            a = true;
+        } else {
+            a = false;
+        }
+
+        if (condition) {
+            a = !0;
+        } else {
+            a = !1;
+        }
+
+        a = condition ? false : true;
+        a = !condition ? false : true;
+        a = condition() ? false : true;
+
+        a = condition ? !3 : !0;
+        a = !condition ? !2 : !0;
+        a = condition() ? !1 : !0;
+
+        if (condition) {
+            a = false;
+        } else {
+            a = true;
+        }
+
+        if (condition) {
+            a = !1;
+        } else {
+            a = !0;
+        }
+
+        a = condition ? 1 : false;
+        a = !condition ? true : 0;
+        a = condition ? 1 : 0;
+    }
+    expect: {
+        var a;
+        a = !!condition;
+        a = !condition;
+        a = !!condition();
+
+        a = !!condition;
+        a = !condition;
+        a = !!condition();
+
+        a = !!condition;
+        a = !!condition;
+
+        a = !condition;
+        a = !!condition;
+        a = !condition();
+
+        a = !condition;
+        a = !!condition;
+        a = !condition();
+
+        a = !condition;
+        a = !condition;
+
+        a = !!condition && 1;
+        a = !condition || 0;
+        a = condition ? 1 : 0;
+    }
+}
+
+cond_8c: {
+    options = {
+        conditionals: true,
+        evaluate    : false,
+        booleans    : false
+    };
+    input: {
+        var a;
+        // compress these
+        a = condition ? true : false;
+        a = !condition ? true : false;
+        a = condition() ? true : false;
+
+        a = condition ? !0 : !1;
+        a = !condition ? !null : !2;
+        a = condition() ? !0 : !-3.5;
+
+        if (condition) {
+            a = true;
+        } else {
+            a = false;
+        }
+
+        if (condition) {
+            a = !0;
+        } else {
+            a = !1;
+        }
+
+        a = condition ? false : true;
+        a = !condition ? false : true;
+        a = condition() ? false : true;
+
+        a = condition ? !3 : !0;
+        a = !condition ? !2 : !0;
+        a = condition() ? !1 : !0;
+
+        if (condition) {
+            a = false;
+        } else {
+            a = true;
+        }
+
+        if (condition) {
+            a = !1;
+        } else {
+            a = !0;
+        }
+
+        a = condition ? 1 : false;
+        a = !condition ? true : 0;
+        a = condition ? 1 : 0;
+    }
+    expect: {
+        var a;
+        a = !!condition;
+        a = !condition;
+        a = !!condition();
+
+        a = !!condition;
+        a = !condition;
+        a = !!condition() || !-3.5;
+
+        a = !!condition;
+        a = !!condition;
+
+        a = !condition;
+        a = !!condition;
+        a = !condition();
+
+        a = !condition;
+        a = !!condition;
+        a = !condition();
+
+        a = !condition;
+        a = !condition;
+
+        a = !!condition && 1;
+        a = !condition || 0;
+        a = condition ? 1 : 0;
+    }
+}
+
+ternary_boolean_consequent: {
+    options = {
+        collapse_vars:true, sequences:true, properties:true, dead_code:true, conditionals:true,
+        comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
+        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+    }
+    input: {
+        function f1() { return a == b ? true : x; }
+        function f2() { return a == b ? false : x; }
+        function f3() { return a < b ? !0 : x; }
+        function f4() { return a < b ? !1 : x; }
+        function f5() { return c ? !0 : x; }
+        function f6() { return c ? false : x; }
+        function f7() { return !c ? true : x; }
+        function f8() { return !c ? !1 : x; }
+    }
+    expect: {
+        function f1() { return a == b || x; }
+        function f2() { return a != b && x; }
+        function f3() { return a < b || x; }
+        function f4() { return !(a < b) && x; }
+        function f5() { return !!c || x; }
+        function f6() { return !c && x; }
+        function f7() { return !c || x; }
+        function f8() { return !!c && x; }
+    }
+}
+
+ternary_boolean_alternative: {
+    options = {
+        collapse_vars:true, sequences:true, properties:true, dead_code:true, conditionals:true,
+        comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
+        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+    }
+    input: {
+        function f1() { return a == b ? x : true; }
+        function f2() { return a == b ? x : false; }
+        function f3() { return a < b ? x : !0; }
+        function f4() { return a < b ? x : !1; }
+        function f5() { return c ? x : true; }
+        function f6() { return c ? x : !1; }
+        function f7() { return !c ? x : !0; }
+        function f8() { return !c ? x : false; }
+    }
+    expect: {
+        function f1() { return a != b || x; }
+        function f2() { return a == b && x; }
+        function f3() { return !(a < b) || x; }
+        function f4() { return a < b && x; }
+        function f5() { return !c || x; }
+        function f6() { return !!c && x; }
+        function f7() { return !!c || x; }
+        function f8() { return !c && x; }
+    }
+}
+
+trivial_boolean_ternary_expressions : {
+    options = {
+        conditionals: true,
+        evaluate    : true,
+        booleans    : true
+    };
+    input: {
+        f('foo' in m ? true  : false);
+        f('foo' in m ? false : true);
+
+        f(g       ? true : false);
+        f(foo()   ? true : false);
+        f("bar"   ? true : false);
+        f(5       ? true : false);
+        f(5.7     ? true : false);
+        f(x - y   ? true : false);
+
+        f(x == y  ? true : false);
+        f(x === y ?   !0 :    !1);
+        f(x < y   ?   !0 : false);
+        f(x <= y  ? true : false);
+        f(x > y   ? true :    !1);
+        f(x >= y  ?   !0 :    !1);
+
+        f(g       ? false : true);
+        f(foo()   ? false : true);
+        f("bar"   ? false : true);
+        f(5       ? false : true);
+        f(5.7     ? false : true);
+        f(x - y   ? false : true);
+
+        f(x == y  ?    !1 :   !0);
+        f(x === y ? false : true);
+
+        f(x < y   ? false : true);
+        f(x <= y  ? false :   !0);
+        f(x > y   ?    !1 : true);
+        f(x >= y  ?    !1 :   !0);
+    }
+    expect: {
+        f('foo' in m);
+        f(!('foo' in m));
+
+        f(!!g);
+        f(!!foo());
+        f(!0);
+        f(!0);
+        f(!0);
+        f(!!(x - y));
+
+        f(x == y);
+        f(x === y);
+        f(x < y);
+        f(x <= y);
+        f(x > y);
+        f(x >= y);
+
+        f(!g);
+        f(!foo());
+        f(!1);
+        f(!1);
+        f(!1);
+        f(!(x - y));
+
+        f(x != y);
+        f(x !== y);
+
+        f(!(x < y));
+        f(!(x <= y));
+        f(!(x > y));
+        f(!(x >= y));
+    }
+}
+
+issue_1154: {
+    options = {
+        conditionals: true,
+        evaluate    : true,
+        booleans    : true,
+        side_effects: true,
+    };
+    input: {
+        function f1(x) { return x ? -1 : -1; }
+        function f2(x) { return x ? +2 : +2; }
+        function f3(x) { return x ? ~3 : ~3; }
+        function f4(x) { return x ? !4 : !4; }
+        function f5(x) { return x ? void 5 : void 5; }
+        function f6(x) { return x ? typeof 6 : typeof 6; }
+
+        function g1() { return g() ? -1 : -1; }
+        function g2() { return g() ? +2 : +2; }
+        function g3() { return g() ? ~3 : ~3; }
+        function g4() { return g() ? !4 : !4; }
+        function g5() { return g() ? void 5 : void 5; }
+        function g6() { return g() ? typeof 6 : typeof 6; }
+    }
+    expect: {
+        function f1(x) { return -1; }
+        function f2(x) { return 2; }
+        function f3(x) { return -4; }
+        function f4(x) { return !1; }
+        function f5(x) { return; }
+        function f6(x) { return "number"; }
+
+        function g1() { return g(), -1; }
+        function g2() { return g(), 2; }
+        function g3() { return g(), -4; }
+        function g4() { return g(), !1; }
+        function g5() { return void g(); }
+        function g6() { return g(), "number"; }
+    }
+}
+
+no_evaluate: {
+    options = {
+        conditionals: true,
+        evaluate    : false,
+        side_effects: true,
+    }
+    input: {
+        function f(b) {
+            a = b ? !0 : !0;
+            a = b ? ~1 : ~1;
+            a = b ? -2 : -2;
+            a = b ? +3 : +3;
+        }
+    }
+    expect: {
+        function f(b) {
+            a = !0;
+            a = ~1;
+            a = -2;
+            a = +3;
+        }
+    }
+}
+
+equality_conditionals_false: {
+    options = {
+        conditionals: false,
+        sequences: true,
+    }
+    input: {
+        function f(a, b, c) {
+            console.log(
+                a == (b ? a : a),
+                a == (b ? a : c),
+                a != (b ? a : a),
+                a != (b ? a : c),
+                a === (b ? a : a),
+                a === (b ? a : c),
+                a !== (b ? a : a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0);
+        f(0, true, 0);
+        f(1, 2, 3);
+        f(1, null, 3);
+        f(NaN);
+        f(NaN, "foo");
+    }
+    expect: {
+        function f(a, b, c) {
+            console.log(
+                a == (b ? a : a),
+                a == (b ? a : c),
+                a != (b ? a : a),
+                a != (b ? a : c),
+                a === (b ? a : a),
+                a === (b ? a : c),
+                a !== (b ? a : a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0),
+        f(0, true, 0),
+        f(1, 2, 3),
+        f(1, null, 3),
+        f(NaN),
+        f(NaN, "foo");
+    }
+    expect_stdout: true
+}
+
+equality_conditionals_true: {
+    options = {
+        conditionals: true,
+        sequences: true,
+    }
+    input: {
+        function f(a, b, c) {
+            console.log(
+                a == (b ? a : a),
+                a == (b ? a : c),
+                a != (b ? a : a),
+                a != (b ? a : c),
+                a === (b ? a : a),
+                a === (b ? a : c),
+                a !== (b ? a : a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0);
+        f(0, true, 0);
+        f(1, 2, 3);
+        f(1, null, 3);
+        f(NaN);
+        f(NaN, "foo");
+    }
+    expect: {
+        function f(a, b, c) {
+            console.log(
+                (b, a == a),
+                a == (b ? a : c),
+                (b, a != a),
+                a != (b ? a : c),
+                (b, a === a),
+                a === (b ? a : c),
+                (b, a !== a),
+                a !== (b ? a : c)
+            );
+        }
+        f(0, 0, 0),
+        f(0, true, 0),
+        f(1, 2, 3),
+        f(1, null, 3),
+        f(NaN),
+        f(NaN, "foo");
+    }
+    expect_stdout: true
+}
+
+issue_1645_1: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        (b = a) ? a++ + (b += a) ? b += a : b += a : b ^= a;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        (b = a) ? (a++ + (b += a), b += a) : b ^= a;
+        console.log(a,b);
+    }
+    expect_stdout: true
+}
+
+issue_1645_2: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        var a = 0;
+        function f() {
+            return a++;
+        }
+        f() ? a += 2 : a += 4;
+        console.log(a);
+    }
+    expect: {
+        var a = 0;
+        function f(){
+            return a++;
+        }
+        f() ? a += 2 : a += 4;
+        console.log(a);
+    }
+    expect_stdout: true
+}
+
+condition_symbol_matches_consequent: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function foo(x, y) {
+            return x ? x : y;
+        }
+        function bar() {
+            return g ? g : h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo(3, null), foo(0, 7), foo(true, false), bar());
+    }
+    expect: {
+        function foo(x, y) {
+            return x || y;
+        }
+        function bar() {
+            return g || h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo(3, null), foo(0, 7), foo(true, false), bar());
+    }
+    expect_stdout: "3 7 true 4"
+}

test/compress/const.js

@@ -0,0 +1,166 @@
+issue_1191: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_vars   : true,
+    }
+    input: {
+        function foo(rot) {
+            const rotTol = 5;
+            if (rot < -rotTol || rot > rotTol)
+                bar();
+            baz();
+        }
+    }
+    expect: {
+        function foo(rot) {
+            (rot < -5 || rot > 5) && bar();
+            baz();
+        }
+    }
+}
+
+issue_1194: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_vars   : true,
+    }
+    input: {
+        function f1() {const a = "X"; return a + a;}
+        function f2() {const aa = "X"; return aa + aa;}
+        function f3() {const aaa = "X"; return aaa + aaa;}
+    }
+    expect: {
+        function f1(){return"XX"}
+        function f2(){return"XX"}
+        function f3(){return"XX"}
+    }
+}
+
+issue_1396: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_vars   : true,
+    }
+    input: {
+        function foo(a) {
+            const VALUE = 1;
+            console.log(2 | VALUE);
+            console.log(VALUE + 1);
+            console.log(VALUE);
+            console.log(a & VALUE);
+        }
+        function bar() {
+            const s = "01234567890123456789";
+            console.log(s + s + s + s + s);
+
+            const CONSTANT = "abc";
+            console.log(CONSTANT + CONSTANT + CONSTANT + CONSTANT + CONSTANT);
+        }
+    }
+    expect: {
+        function foo(a) {
+            console.log(3);
+            console.log(2);
+            console.log(1);
+            console.log(1 & a);
+        }
+        function bar() {
+            const s = "01234567890123456789";
+            console.log(s + s + s + s + s);
+
+            console.log("abcabcabcabcabc");
+        }
+    }
+}
+
+unused_regexp_literal: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+    }
+    input: {
+        function f(){ var a = /b/; }
+    }
+    expect: {
+        function f(){}
+    }
+}
+
+regexp_literal_not_const: {
+    options = {
+        evaluate      : true,
+        booleans      : true,
+        comparisons   : true,
+        dead_code     : true,
+        conditionals  : true,
+        side_effects  : true,
+        unused        : true,
+        hoist_funs    : true,
+        if_return     : true,
+        join_vars     : true,
+        sequences     : false,
+        collapse_vars : false,
+        reduce_vars   : true,
+    }
+    input: {
+        (function(){
+            var result;
+            const s = 'acdabcdeabbb';
+            const REGEXP_LITERAL = /ab*/g;
+            while (result = REGEXP_LITERAL.exec(s)) {
+                console.log(result[0]);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            var result;
+            const REGEXP_LITERAL = /ab*/g;
+            while (result = REGEXP_LITERAL.exec("acdabcdeabbb")) console.log(result[0]);
+        })();
+    }
+    expect_stdout: true
+}

test/compress/dead-code.js

@@ -64,7 +64,8 @@ dead_code_constant_boolean_should_warn_more: {
         loops        : true,
         booleans     : true,
         conditionals : true,
-        evaluate     : true
+        evaluate     : true,
+        side_effects : true,
     };
     input: {
         while (!((foo && bar) || (x + "0"))) {
@@ -72,7 +73,7 @@ dead_code_constant_boolean_should_warn_more: {
             var foo;
             function bar() {}
         }
-        for (var x = 10; x && (y || x) && (!typeof x); ++x) {
+        for (var x = 10, y; x && (y || x) && (!typeof x); ++x) {
             asdf();
             foo();
             var moo;
@@ -83,7 +84,155 @@ dead_code_constant_boolean_should_warn_more: {
         function bar() {}
         // nothing for the while
         // as for the for, it should keep:
-        var x = 10;
+        var x = 10, y;
         var moo;
     }
+    expect_stdout: true
+}
+
+dead_code_block_decls_die: {
+    options = {
+        dead_code    : true,
+        conditionals : true,
+        booleans     : true,
+        evaluate     : true
+    };
+    input: {
+        if (0) {
+            let foo = 6;
+            const bar = 12;
+            class Baz {};
+            var qux;
+        }
+        console.log(foo, bar, Baz);
+    }
+    expect: {
+        var qux;
+        console.log(foo, bar, Baz);
+    }
+}
+
+dead_code_const_declaration: {
+    options = {
+        dead_code    : true,
+        loops        : true,
+        booleans     : true,
+        conditionals : true,
+        evaluate     : true,
+        reduce_vars  : true,
+    };
+    input: {
+        var unused;
+        const CONST_FOO = false;
+        if (CONST_FOO) {
+            console.log("unreachable");
+            var moo;
+            function bar() {}
+        }
+    }
+    expect: {
+        var unused;
+        const CONST_FOO = !1;
+        var moo;
+        function bar() {}
+    }
+    expect_stdout: true
+}
+
+dead_code_const_annotation: {
+    options = {
+        dead_code    : true,
+        loops        : true,
+        booleans     : true,
+        conditionals : true,
+        evaluate     : true,
+        reduce_vars  : true,
+        toplevel     : true,
+    };
+    input: {
+        var unused;
+        /** @const */ var CONST_FOO_ANN = false;
+        if (CONST_FOO_ANN) {
+            console.log("unreachable");
+            var moo;
+            function bar() {}
+        }
+    }
+    expect: {
+        var unused;
+        var CONST_FOO_ANN = !1;
+        var moo;
+        function bar() {}
+    }
+    expect_stdout: true
+}
+
+dead_code_const_annotation_regex: {
+    options = {
+        dead_code    : true,
+        loops        : true,
+        booleans     : true,
+        conditionals : true,
+        evaluate     : true
+    };
+    input: {
+        var unused;
+        // @constraint this shouldn't be a constant
+        var CONST_FOO_ANN = false;
+        if (CONST_FOO_ANN) {
+            console.log("reachable");
+        }
+    }
+    expect: {
+        var unused;
+        var CONST_FOO_ANN = !1;
+        CONST_FOO_ANN && console.log('reachable');
+    }
+    expect_stdout: true
+}
+
+dead_code_const_annotation_complex_scope: {
+    options = {
+        dead_code    : true,
+        loops        : true,
+        booleans     : true,
+        conditionals : true,
+        evaluate     : true,
+        reduce_vars  : true,
+        toplevel     : true,
+    };
+    input: {
+        var unused_var;
+        /** @const */ var test = 'test';
+        // @const
+        var CONST_FOO_ANN = false;
+        var unused_var_2;
+        if (CONST_FOO_ANN) {
+            console.log("unreachable");
+            var moo;
+            function bar() {}
+        }
+        if (test === 'test') {
+            var beef = 'good';
+            /** @const */ var meat = 'beef';
+            var pork = 'bad';
+            if (meat === 'pork') {
+                console.log('also unreachable');
+            } else if (pork === 'good') {
+                console.log('reached, not const');
+            }
+        }
+    }
+    expect: {
+        var unused_var;
+        var test = 'test';
+        var CONST_FOO_ANN = !1;
+        var unused_var_2;
+        var moo;
+        function bar() {}
+        var beef = 'good';
+        var meat = 'beef';
+        var pork = 'bad';
+    }
+    expect_stdout: true
 }

test/compress/destructuring.js

@@ -0,0 +1,309 @@
+destructuring_arrays: {
+    input: {
+        {const [aa, bb] = cc;}
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, bb] = cc;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, bb] = cc;
+        var [aa, [bb, cc]] = dd;
+        var [,[,,,,,],,,zz,] = xx; // Trailing comma
+        var [,,zzz,,] = xxx; // Trailing comma after hole
+    }
+    expect: {
+        {const [aa, bb] = cc;}
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, bb] = cc;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, bb] = cc;
+        var [aa, [bb, cc]] = dd;
+        var [,[,,,,,],,,zz] = xx;
+        var [,,zzz,,] = xxx;
+    }
+}
+
+destructuring_arrays_holes: {
+    input: {
+        var [,,,,] = a;
+        var [,,b,] = c;
+        var [d,,]  = e;
+    }
+    expect_exact: "var[,,,,]=a;var[,,b]=c;var[d,,]=e;"
+}
+
+destructuring_objects: {
+    input: {
+        {const {aa, bb} = {aa:1, bb:2};}
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb} = {aa:1, bb:2};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb} = {aa:1, bb:2};
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+    }
+    expect: {
+        {const {aa, bb} = {aa:1, bb:2};}
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb} = {aa:1, bb:2};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb} = {aa:1, bb:2};
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+    }
+}
+
+destructuring_objects_trailing_elision: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        var {cc,} = foo;
+    }
+    expect_exact: "var{cc}=foo;"
+}
+
+nested_destructuring_objects: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        const [{a},b] = c;
+        let [{a},b] = c;
+        var [{a},b] = c;
+    }
+    expect_exact: 'const[{a},b]=c;let[{a},b]=c;var[{a},b]=c;';
+}
+
+destructuring_constdef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        for (const [x,y] in pairs);
+        for (const [a] = 0;;);
+        for (const {c} of cees);
+    }
+    expect_exact: "for(const[x,y]in pairs);for(const[a]=0;;);for(const{c}of cees);"
+}
+
+destructuring_letdef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        for (let [x,y] in pairs);
+        for (let [a] = 0;;);
+        for (let {c} of cees);
+    }
+    expect_exact: "for(let[x,y]in pairs);for(let[a]=0;;);for(let{c}of cees);"
+}
+
+destructuring_vardef_in_loops: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        for (var [x,y] in pairs);
+        for (var [a] = 0;;);
+        for (var {c} of cees);
+    }
+    expect_exact: "for(var[x,y]in pairs);for(var[a]=0;;);for(var{c}of cees);"
+}
+
+destructuring_expressions: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        ({a, b});
+        [{a}];
+        f({x});
+    }
+    expect_exact: "({a,b});[{a}];f({x});"
+}
+
+destructuring_remove_unused_1: {
+    options = {
+        unused: true
+    }
+    input: {
+        function a() {
+            var unused = "foo";
+            var a = [1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var unused = "foo";
+            var a = {b: 1};
+            var {b} = a;
+            f(b);
+        }
+        function c() {
+            var unused = "foo";
+            var a = [[1]];
+            var [[b]] = a;
+            f(b);
+        }
+        function d() {
+            var unused = "foo";
+            var a = {b: {b:1}};
+            var {b:{b}} = a;
+            f(b);
+        }
+        function e() {
+            var unused = "foo";
+            var a = [1, 2, 3, 4, 5];
+            var [b, ...c] = a;
+            f(b, c);
+        }
+    }
+    expect: {
+        function a() {
+            var a = [1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var a = {b: 1};
+            var {b} = a;
+            f(b);
+        }
+        function c() {
+            var a = [[1]];
+            var [[b]] = a;
+            f(b);
+        }
+        function d() {
+            var a = {b: {b:1}};
+            var {b:{b}} = a;
+            f(b);
+        }
+        function e() {
+            var a = [1, 2, 3, 4, 5];
+            var [b, ...c] = a;
+            f(b, c);
+        }
+    }
+}
+
+destructuring_remove_unused_2: {
+    options = {
+        unused: true
+    }
+    input: {
+        function a() {
+            var unused = "foo";
+            var a = [,,1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var unused = "foo";
+            var a = [{a: [1]}];
+            var [{b: a}] = a;
+            f(b);
+        }
+    }
+    expect: {
+        function a() {
+            var a = [,,1];
+            var [b] = a;
+            f(b);
+        }
+        function b() {
+            var a = [{a: [1]}];
+            var [{b: a}] = a;
+            f(b);
+        }
+    }
+}
+
+object_destructuring_may_need_parentheses: {
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        ({a, b} = {a: 1, b: 2});
+    }
+    expect_exact: "({a,b}={a:1,b:2});"
+}
+
+destructuring_with_undefined_as_default_assignment: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        [foo = undefined] = bar;
+        [foo = void 0] = bar;
+    }
+    expect: {
+        [foo] = bar;
+        [foo] = bar;
+    }
+}
+
+destructuring_dont_evaluate_with_undefined_as_default_assignment: {
+    options = {
+        evaluate: false
+    }
+    input: {
+        [foo = undefined] = bar;
+    }
+    expect: {
+        [foo = void 0] = bar;
+    }
+}
+
+reduce_vars: {
+    options = {
+        reduce_vars: true,
+    }
+    input: {
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, [bb, cc]] = dd;
+        [aa, [bb, cc]] = dd;
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+        ({aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}});
+        const [{a},b] = c;
+        let [{a},b] = c;
+        var [{a},b] = c;
+        [{a},b] = c;
+        for (const [x,y] in pairs);
+        for (let [x,y] in pairs);
+        for (var [x,y] in pairs);
+        for ([x,y] in pairs);
+    }
+    expect: {
+        {const [aa, [bb, cc]] = dd;}
+        {let [aa, [bb, cc]] = dd;}
+        var [aa, [bb, cc]] = dd;
+        [aa, [bb, cc]] = dd;
+        {const {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        {let {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};}
+        var {aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}};
+        ({aa, bb: {cc, dd}} = {aa:1, bb: {cc:2, dd: 3}});
+        const [{a},b] = c;
+        let [{a},b] = c;
+        var [{a},b] = c;
+        [{a},b] = c;
+        for (const [x,y] in pairs);
+        for (let [x,y] in pairs);
+        for (var [x,y] in pairs);
+        for ([x,y] in pairs);
+    }
+}
+
+unused: {
+    options = {
+        unused: true,
+    }
+    input: {
+        let { foo: [, , ...a] } = { foo: [1, 2, 3, 4], bar: 5 };
+        console.log(a);
+    }
+    expect: {
+        let { foo: [, , ...a] } = { foo: [1, 2, 3, 4], bar: 5 };
+        console.log(a);
+    }
+}

test/compress/directives.js

@@ -0,0 +1,10 @@
+class_directives_compression: {
+    input: {
+        class foo {
+            foo() {
+                "use strict";
+            }
+        }
+    }
+    expect_exact: "class foo{foo(){}}"
+}

test/compress/drop-console.js

@@ -0,0 +1,24 @@
+drop_console_1: {
+    options = {};
+    input: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+    expect: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+}
+
+drop_console_2: {
+    options = { drop_console: true };
+    input: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+    expect: {
+        // with regular compression these will be stripped out as well
+        void 0;
+        void 0;
+    }
+}

test/compress/drop-unused.js

@@ -1,5 +1,5 @@
 unused_funarg_1: {
-    options = { unused: true };
+    options = { unused: true, keep_fargs: false };
     input: {
         function f(a, b, c, d, e) {
             return a + b;
@@ -13,7 +13,7 @@ unused_funarg_1: {
 }
 
 unused_funarg_2: {
-    options = { unused: true };
+    options = { unused: true, keep_fargs: false };
     input: {
         function f(a, b, c, d, e) {
             return a + c;
@@ -95,3 +95,920 @@ unused_circular_references_3: {
         }
     }
 }
+
+unused_keep_setter_arg: {
+    options = { unused: true };
+    input: {
+        var x = {
+            _foo: null,
+            set foo(val) {
+            },
+            get foo() {
+                return this._foo;
+            }
+        }
+    }
+    expect: {
+        var x = {
+            _foo: null,
+            set foo(val) {
+            },
+            get foo() {
+                return this._foo;
+            }
+        }
+    }
+}
+
+unused_var_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                var x = 10;
+            }
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {}
+        }
+    }
+}
+
+used_var_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                var x = 10;
+            }
+            return x;
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                var x = 10;
+            }
+            return x;
+        }
+    }
+}
+
+unused_block_decls_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                let x = 10;
+                const y = 10;
+                class Zee {};
+            }
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {}
+        }
+    }
+}
+
+used_block_decls_in_catch: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {
+                let x = 10;
+                const y = 10;
+                class Zee {};
+            }
+            console.log(x, y, Zee);
+        }
+    }
+    expect: {
+        function foo() {
+            try {
+                foo();
+            } catch(ex) {}
+            console.log(x, y, Zee);
+        }
+    }
+}
+
+unused_block_decls: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            {
+                const x;
+            }
+            {
+                let y;
+            }
+            console.log(x, y);
+        }
+    }
+    expect: {
+        function foo() {
+            console.log(x, y);
+        }
+    }
+}
+
+unused_keep_harmony_destructuring: {
+    options = { unused: true };
+    input: {
+        function foo() {
+            var {x, y} = foo;
+            var a = foo;
+        }
+    }
+    expect:  {
+        function foo() {
+            var {x, y} = foo;
+        }
+    }
+}
+
+keep_fnames: {
+    options = { unused: true, keep_fnames: true, unsafe: true };
+    input: {
+        function foo() {
+            return function bar(baz) {};
+        }
+    }
+    expect: {
+        function foo() {
+            return function bar(baz) {};
+        }
+    }
+}
+
+drop_assign: {
+    options = { unused: true };
+    input: {
+        function f1() {
+            var a;
+            a = 1;
+        }
+        function f2() {
+            var a = 1;
+            a = 2;
+        }
+        function f3(a) {
+            a = 1;
+        }
+        function f4() {
+            var a;
+            return a = 1;
+        }
+        function f5() {
+            var a;
+            return function() {
+                a = 1;
+            }
+        }
+    }
+    expect: {
+        function f1() {
+            1;
+        }
+        function f2() {
+            2;
+        }
+        function f3(a) {
+            1;
+        }
+        function f4() {
+            return 1;
+        }
+        function f5() {
+            var a;
+            return function() {
+                a = 1;
+            }
+        }
+    }
+}
+
+keep_assign: {
+    options = { unused: "keep_assign" };
+    input: {
+        function f1() {
+            var a;
+            a = 1;
+        }
+        function f2() {
+            var a = 1;
+            a = 2;
+        }
+        function f3(a) {
+            a = 1;
+        }
+        function f4() {
+            var a;
+            return a = 1;
+        }
+        function f5() {
+            var a;
+            return function() {
+                a = 1;
+            }
+        }
+    }
+    expect: {
+        function f1() {
+            var a;
+            a = 1;
+        }
+        function f2() {
+            var a = 1;
+            a = 2;
+        }
+        function f3(a) {
+            a = 1;
+        }
+        function f4() {
+            var a;
+            return a = 1;
+        }
+        function f5() {
+            var a;
+            return function() {
+                a = 1;
+            }
+        }
+    }
+}
+
+drop_toplevel_funcs: {
+    options = { toplevel: "funcs", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, b = 1, c = g;
+        a = 2;
+        function g() {}
+        console.log(b = 3);
+    }
+}
+
+drop_toplevel_vars: {
+    options = { toplevel: "vars", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        2;
+        function g() {}
+        function h() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_vars_fargs: {
+    options = { keep_fargs: false, toplevel: "vars", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var c = g;
+        function f() {
+            return function() {
+                c = 2;
+            }
+        }
+        2;
+        function g() {}
+        function h() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_all: {
+    options = { toplevel: true, unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        2;
+        console.log(3);
+    }
+}
+
+drop_toplevel_retain: {
+    options = { top_retain: "f,a,o", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_retain_array: {
+    options = { top_retain: [ "f", "a", "o" ], unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_retain_regex: {
+    options = { top_retain: /^[fao]$/, unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_all_retain: {
+    options = { toplevel: true, top_retain: "f,a,o", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_funcs_retain: {
+    options = { toplevel: "funcs", top_retain: "f,a,o", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        console.log(b = 3);
+    }
+}
+
+drop_toplevel_vars_retain: {
+    options = { toplevel: "vars", top_retain: "f,a,o", unused: true };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(3);
+    }
+}
+
+drop_toplevel_keep_assign: {
+    options = { toplevel: true, unused: "keep_assign" };
+    input: {
+        var a, b = 1, c = g;
+        function f(d) {
+            return function() {
+                c = 2;
+            }
+        }
+        a = 2;
+        function g() {}
+        function h() {}
+        console.log(b = 3);
+    }
+    expect: {
+        var a, b = 1;
+        a = 2;
+        console.log(b = 3);
+    }
+}
+
+drop_fargs: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var b = a;
+        }
+    }
+    expect: {
+        function f() {}
+    }
+}
+
+drop_fnames: {
+    options = {
+        keep_fnames: false,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return function g() {
+                var a = g;
+            };
+        }
+    }
+    expect: {
+        function f() {
+            return function() {};
+        }
+    }
+}
+
+global_var: {
+    options = {
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var a;
+        function foo(b) {
+            a;
+            b;
+            c;
+            typeof c === "undefined";
+            c + b + a;
+            b && b.ar();
+            return b;
+        }
+    }
+    expect: {
+        var a;
+        function foo(b) {
+            c;
+            c;
+            b && b.ar();
+            return b;
+        }
+    }
+}
+
+iife: {
+    options = {
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a;
+            ~function() {}(b);
+        }
+    }
+    expect: {
+        function f() {
+            b;
+        }
+    }
+}
+
+drop_value: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        (1, [2, foo()], 3, {a:1, b:bar()});
+    }
+    expect: {
+        foo(), bar();
+    }
+}
+
+const_assign: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            const b = 2;
+            return 1 + b;
+        }
+
+        function g() {
+            const b = 2;
+            b = 3;
+            return 1 + b;
+        }
+    }
+    expect: {
+        function f() {
+            return 3;
+        }
+
+        function g() {
+            const b = 2;
+            b = 3;
+            return 1 + b;
+        }
+    }
+}
+
+issue_1539: {
+    options = {
+        cascade: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a, b;
+            a = b = 42;
+            return a;
+        }
+    }
+    expect: {
+        function f() {
+            return 42;
+        }
+    }
+}
+
+vardef_value: {
+    options = {
+        keep_fnames: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g(){
+                return x();
+            }
+            var a = g();
+            return a(42);
+        }
+    }
+    expect: {
+        function f() {
+            var a = function(){
+                return x();
+            }();
+            return a(42);
+        }
+    }
+}
+
+assign_binding: {
+    options = {
+        cascade: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a;
+            a = f.g, a();
+        }
+    }
+    expect: {
+        function f() {
+            (0, f.g)();
+        }
+    }
+}
+
+assign_chain: {
+    options = {
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a, b;
+            x = a = y = b = 42;
+        }
+    }
+    expect: {
+        function f() {
+            x = y = 42;
+        }
+    }
+}
+
+issue_1583: {
+    options = {
+        keep_fargs: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function m(t) {
+            (function(e) {
+                t = e();
+            })(function() {
+                return (function(a) {
+                    return a;
+                })(function(a) {});
+            });
+        }
+    }
+    expect: {
+        function m(t) {
+            (function(e) {
+                t = (function() {
+                    return (function(a) {
+                        return a;
+                    })(function(a) {});
+                })();
+            })();
+        }
+    }
+}
+
+issue_1656: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        for(var a=0;;);
+    }
+    expect_exact: "for (;;) ;"
+}
+
+issue_1709: {
+    options = {
+        unused: true,
+    }
+    input: {
+        console.log(
+            function x() {
+                var x = 1;
+                return x;
+            }(),
+            function y() {
+                const y = 2;
+                return y;
+            }(),
+            function z() {
+                function z() {}
+                return z;
+            }()
+        );
+    }
+    expect: {
+        console.log(
+            function() {
+                var x = 1;
+                return x;
+            }(),
+            function() {
+                const y = 2;
+                return y;
+            }(),
+            function() {
+                function z() {}
+                return z;
+            }()
+        );
+    }
+    expect_stdout: true
+}
+
+issue_1715_1: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            a++;
+            try {} catch (a) {
+                var a;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            a++;
+            try {} catch (a) {
+                var a;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_1715_2: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            a++;
+            try {} catch (a) {
+                var a = 2;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            a++;
+            try {} catch (a) {
+                var a;
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}
+
+issue_1715_3: {
+    options = {
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            a++;
+            try {} catch (a) {
+                var a = 2 + x();
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            a++;
+            try {} catch (a) {
+                var a = x();
+            }
+        }
+        f();
+        console.log(a);
+    }
+    expect_stdout: "1"
+}

test/compress/evaluate.js

@@ -0,0 +1,898 @@
+and: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        // compress these
+
+        a = true     && condition;
+        a = 1        && console.log("a");
+        a = 2 * 3    && 2 * condition;
+        a = 5 == 5   && condition + 3;
+        a = "string" && 4 - condition;
+        a = 5 + ""   && condition / 5;
+        a = -4.5     && 6 << condition;
+        a = 6        && 7;
+
+        a = false     && condition;
+        a = NaN       && console.log("b");
+        a = 0         && console.log("c");
+        a = undefined && 2 * condition;
+        a = null      && condition + 3;
+        a = 2 * 3 - 6 && 4 - condition;
+        a = 10 == 7   && condition / 5;
+        a = !"string" && 6 % condition;
+        a = 0         && 7;
+
+        // don't compress these
+
+        a = condition        && true;
+        a = console.log("a") && 2;
+        a = 4 - condition    && "string";
+        a = 6 << condition   && -4.5;
+
+        a = condition        && false;
+        a = console.log("b") && NaN;
+        a = console.log("c") && 0;
+        a = 2 * condition    && undefined;
+        a = condition + 3    && null;
+
+    }
+    expect: {
+        var a;
+
+        a = condition;
+        a = console.log("a");
+        a = 2 * condition;
+        a = condition + 3;
+        a = 4 - condition;
+        a = condition / 5;
+        a = 6 << condition;
+        a = 7;
+
+        a = false;
+        a = NaN;
+        a = 0;
+        a = void 0;
+        a = null;
+        a = 0;
+        a = false;
+        a = false;
+        a = 0;
+
+        a = condition        && true;
+        a = console.log("a") && 2;
+        a = 4 - condition    && "string";
+        a = 6 << condition   && -4.5;
+
+        a = condition        && false;
+        a = console.log("b") && NaN;
+        a = console.log("c") && 0;
+        a = 2 * condition    && void 0;
+        a = condition + 3    && null;
+    }
+}
+
+or: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        // compress these
+
+        a = true     || condition;
+        a = 1        || console.log("a");
+        a = 2 * 3    || 2 * condition;
+        a = 5 == 5   || condition + 3;
+        a = "string" || 4 - condition;
+        a = 5 + ""   || condition / 5;
+        a = -4.5     || 6 << condition;
+        a = 6        || 7;
+
+        a = false     || condition;
+        a = 0         || console.log("b");
+        a = NaN       || console.log("c");
+        a = undefined || 2 * condition;
+        a = null      || condition + 3;
+        a = 2 * 3 - 6 || 4 - condition;
+        a = 10 == 7   || condition / 5;
+        a = !"string" || 6 % condition;
+        a = null      || 7;
+
+        a = console.log(undefined && condition || null);
+        a = console.log(undefined || condition && null);
+
+        // don't compress these
+
+        a = condition        || true;
+        a = console.log("a") || 2;
+        a = 4 - condition    || "string";
+        a = 6 << condition   || -4.5;
+
+        a = condition        || false;
+        a = console.log("b") || NaN;
+        a = console.log("c") || 0;
+        a = 2 * condition    || undefined;
+        a = condition + 3    || null;
+
+    }
+    expect: {
+        var a;
+
+        a = true;
+        a = 1;
+        a = 6;
+        a = true;
+        a = "string";
+        a = "5";
+        a = -4.5;
+        a = 6;
+
+        a = condition;
+        a = console.log("b");
+        a = console.log("c");
+        a = 2 * condition;
+        a = condition + 3;
+        a = 4 - condition;
+        a = condition / 5;
+        a = 6 % condition;
+        a = 7;
+
+        a = console.log(null);
+        a = console.log(condition && null);
+
+        a = condition        || true;
+        a = console.log("a") || 2;
+        a = 4 - condition    || "string";
+        a = 6 << condition   || -4.5;
+
+        a = condition        || false;
+        a = console.log("b") || NaN;
+        a = console.log("c") || 0;
+        a = 2 * condition    || void 0;
+        a = condition + 3    || null;
+    }
+}
+
+unary_prefix: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        a = !0 && b;
+        a = !0 || b;
+        a = ~1 && b;
+        a = ~1 || b;
+        a = -2 && b;
+        a = -2 || b;
+        a = +3 && b;
+        a = +3 || b;
+    }
+    expect: {
+        a = b;
+        a = !0;
+        a = b;
+        a = -2;
+        a = b;
+        a = -2;
+        a = b;
+        a = 3;
+    }
+}
+
+negative_zero: {
+    options = { evaluate: true }
+    input: {
+        console.log(
+            -"",
+            - -"",
+            1 / (-0),
+            1 / (-"")
+        );
+    }
+    expect: {
+        console.log(
+            -0,
+            0,
+            1 / (-0),
+            1 / (-0)
+        );
+    }
+    expect_stdout: true
+}
+
+positive_zero: {
+    options = { evaluate: true }
+    input: {
+        console.log(
+            +"",
+            + -"",
+            1 / (+0),
+            1 / (+"")
+        );
+    }
+    expect: {
+        console.log(
+            0,
+            -0,
+            1 / (0),
+            1 / (0)
+        );
+    }
+    expect_stdout: true
+}
+
+pow: {
+    options = { evaluate: true }
+    input: {
+        var a = 5 ** 3;
+    }
+    expect: {
+        var a = 125;
+    }
+}
+
+pow_sequence: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = 2 ** 3 ** 2;
+    }
+    expect: {
+        var a = 512;
+    }
+}
+
+pow_mixed: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = 5 + 2 ** 3 + 5;
+        var b = 5 * 3 ** 2;
+        var c = 5 ** 3 * 2;
+        var d = 5 ** +3;
+    }
+    expect: {
+        var a = 18;
+        var b = 45;
+        var c = 250;
+        var d = 125;
+    }
+}
+
+pow_with_right_side_evaluating_to_unary: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = (4 - 7) ** foo;
+        var b = ++bar ** 3;
+        var c = --baz ** 2;
+    }
+    expect_exact: "var a=(-3)**foo;var b=++bar**3;var c=--baz**2;"
+}
+
+pow_with_number_constants: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a = 5 ** NaN;
+        /* NaN exponent results to NaN */
+        var b = 42 ** +0;
+        /* +0 exponent results to NaN */
+        var c = 42 ** -0;
+        /* -0 exponent results to NaN */
+        var d = NaN ** 1;
+        /* NaN with non-zero exponent is NaN */
+        var e = 2 ** Infinity;
+        /* abs(base) > 1 with Infinity as exponent is Infinity */
+        var f = 2 ** -Infinity;
+        /* abs(base) > 1 with -Infinity as exponent is +0 */
+        var g = (-7) ** (0.5);
+        var h = 2324334 ** 34343443;
+        var i = (-2324334) ** 34343443;
+        var j = 2 ** (-3);
+        var k = 2.0 ** -3;
+        var l = 2.0 ** (5 - 7);
+        var m = 3 ** -10;  // Result will be 0.000016935087808430286, which is too long
+    }
+    expect: {
+        var a = NaN;
+        var b = 1;
+        var c = 1;
+        var d = NaN;
+        var e = Infinity;
+        var f = 0;
+        var g = NaN;
+        var h = Infinity;
+        var i = -Infinity;
+        var j = .125;
+        var k = .125;
+        var l = .25;
+        var m = 3 ** -10;
+    }
+}
+
+unsafe_constant: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            true.a,
+            false.a,
+            null.a,
+            undefined.a
+        );
+    }
+    expect: {
+        console.log(
+            true.a,
+            false.a,
+            null.a,
+            (void 0).a
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_object: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:1}) + 1,
+            ({a:1}).a + 1,
+            ({a:1}).b + 1,
+            ({a:1}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:1}) + 1,
+            2,
+            ({a:1}).b + 1,
+            1..b + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_object_nested: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1}}) + 1,
+            ({a:{b:1}}).a + 1,
+            ({a:{b:1}}).b + 1,
+            ({a:{b:1}}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1}}) + 1,
+            ({a:{b:1}}).a + 1,
+            ({a:{b:1}}).b + 1,
+            2
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_object_complex: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1},b:1}) + 1,
+            ({a:{b:1},b:1}).a + 1,
+            ({a:{b:1},b:1}).b + 1,
+            ({a:{b:1},b:1}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1},b:1}) + 1,
+            ({a:{b:1},b:1}).a + 1,
+            2,
+            2
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_object_repeated: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1},a:1}) + 1,
+            ({a:{b:1},a:1}).a + 1,
+            ({a:{b:1},a:1}).b + 1,
+            ({a:{b:1},a:1}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1},a:1}) + 1,
+            2,
+            ({a:{b:1},a:1}).b + 1,
+            1..b + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_object_accessor: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        function f() {
+            var a = {
+                get b() {},
+                set b() {}
+            };
+            return {a:a};
+        }
+    }
+    expect: {
+        function f() {
+            var a = {
+                get b() {},
+                set b() {}
+            };
+            return {a:a};
+        }
+    }
+}
+
+unsafe_function: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({a:{b:1},b:function(){}}) + 1,
+            ({a:{b:1},b:function(){}}).a + 1,
+            ({a:{b:1},b:function(){}}).b + 1,
+            ({a:{b:1},b:function(){}}).a.b + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({a:{b:1},b:function(){}}) + 1,
+            ({a:{b:1},b:function(){}}).a + 1,
+            ({a:{b:1},b:function(){}}).b + 1,
+            ({a:{b:1},b:function(){}}).a.b + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_integer_key: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({0:1}) + 1,
+            ({0:1})[0] + 1,
+            ({0:1})["0"] + 1,
+            ({0:1})[1] + 1,
+            ({0:1})[0][1] + 1,
+            ({0:1})[0]["1"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({0:1}) + 1,
+            2,
+            2,
+            ({0:1})[1] + 1,
+            1[1] + 1,
+            1["1"] + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_integer_key_complex: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({0:{1:1},1:1}) + 1,
+            ({0:{1:1},1:1})[0] + 1,
+            ({0:{1:1},1:1})["0"] + 1,
+            ({0:{1:1},1:1})[1] + 1,
+            ({0:{1:1},1:1})[0][1] + 1,
+            ({0:{1:1},1:1})[0]["1"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({0:{1:1},1:1}) + 1,
+            "[object Object]1",
+            "[object Object]1",
+            2,
+            2,
+            2
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_float_key: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({2.72:1}) + 1,
+            ({2.72:1})[2.72] + 1,
+            ({2.72:1})["2.72"] + 1,
+            ({2.72:1})[3.14] + 1,
+            ({2.72:1})[2.72][3.14] + 1,
+            ({2.72:1})[2.72]["3.14"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            ({2.72:1}) + 1,
+            2,
+            2,
+            ({2.72:1})[3.14] + 1,
+            1[3.14] + 1,
+            1["3.14"] + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_float_key_complex: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            ({2.72:{3.14:1},3.14:1}) + 1,
+            ({2.72:{3.14:1},3.14:1})[2.72] + 1,
+            ({2.72:{3.14:1},3.14:1})["2.72"] + 1,
+            ({2.72:{3.14:1},3.14:1})[3.14] + 1,
+            ({2.72:{3.14:1},3.14:1})[2.72][3.14] + 1,
+            ({2.72:{3.14:1},3.14:1})[2.72]["3.14"] + 1
+        );
+    }
+    expect: {
+        console.log(
+            "[object Object]1",
+            "[object Object]1",
+            "[object Object]1",
+            2,
+            2,
+            2
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_array: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            [1, , 3][1],
+            [1, 2, 3, a] + 1,
+            [1, 2, 3, 4] + 1,
+            [1, 2, 3, a][0] + 1,
+            [1, 2, 3, 4][0] + 1,
+            [1, 2, 3, 4][6 - 5] + 1,
+            [1, , 3, 4][6 - 5] + 1,
+            [[1, 2], [3, 4]][0] + 1,
+            [[1, 2], [3, 4]][6 - 5][1] + 1,
+            [[1, 2], , [3, 4]][6 - 5][1] + 1
+        );
+    }
+    expect: {
+        console.log(
+            void 0,
+            [1, 2, 3, a] + 1,
+            "1,2,3,41",
+            [1, 2, 3, a][0] + 1,
+            2,
+            3,
+            NaN,
+            "1,21",
+            5,
+            (void 0)[1] + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_string: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234" + 1,
+            "1234"[0] + 1,
+            "1234"[6 - 5] + 1,
+            ("12" + "34")[0] + 1,
+            ("12" + "34")[6 - 5] + 1,
+            [1, 2, 3, 4].join("")[0] + 1
+        );
+    }
+    expect: {
+        console.log(
+            "12341",
+            "11",
+            "21",
+            "11",
+            "21",
+            "11"
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_array_bad_index: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            [1, 2, 3, 4].a + 1,
+            [1, 2, 3, 4]["a"] + 1,
+            [1, 2, 3, 4][3.14] + 1
+        );
+    }
+    expect: {
+        console.log(
+            [1, 2, 3, 4].a + 1,
+            [1, 2, 3, 4]["a"] + 1,
+            [1, 2, 3, 4][3.14] + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_string_bad_index: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234".a + 1,
+            "1234"["a"] + 1,
+            "1234"[3.14] + 1
+        );
+    }
+    expect: {
+        console.log(
+            "1234".a + 1,
+            "1234"["a"] + 1,
+            "1234"[3.14] + 1
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_prototype_function: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        var a = ({valueOf: 0}) < 1;
+        var b = ({toString: 0}) < 1;
+        var c = ({valueOf: 0}) + "";
+        var d = ({toString: 0}) + "";
+        var e = (({valueOf: 0}) + "")[2];
+        var f = (({toString: 0}) + "")[2];
+        var g = ({valueOf: 0}).valueOf();
+        var h = ({toString: 0}).toString();
+    }
+    expect: {
+        var a = ({valueOf: 0}) < 1;
+        var b = ({toString: 0}) < 1;
+        var c = ({valueOf: 0}) + "";
+        var d = ({toString: 0}) + "";
+        var e = (({valueOf: 0}) + "")[2];
+        var f = (({toString: 0}) + "")[2];
+        var g = ({valueOf: 0}).valueOf();
+        var h = "" + ({toString: 0});
+    }
+}
+
+call_args: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(1, 1);
+    }
+    expect_stdout: true
+}
+
+call_args_drop_param: {
+    options = {
+        evaluate: true,
+        keep_fargs: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        const a = 1;
+        console.log(a);
+        +function(a) {
+            return a;
+        }(a, b);
+    }
+    expect: {
+        const a = 1;
+        console.log(1);
+        +(b, 1);
+    }
+    expect_stdout: true
+}
+
+in_boolean_context: {
+    options = {
+        booleans: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(
+            !42,
+            !"foo",
+            ![1, 2],
+            !/foo/,
+            !b(42),
+            !b("foo"),
+            !b([1, 2]),
+            !b(/foo/),
+            ![1, foo()],
+            ![1, foo(), 2]
+        );
+    }
+    expect: {
+        console.log(
+            !1,
+            !1,
+            !1,
+            !1,
+            !b(42),
+            !b("foo"),
+            !b([1, 2]),
+            !b(/foo/),
+            ![1, foo()],
+            (foo(), !1)
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_charAt: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234" + 1,
+            "1234".charAt(0) + 1,
+            "1234".charAt(6 - 5) + 1,
+            ("12" + "34").charAt(0) + 1,
+            ("12" + "34").charAt(6 - 5) + 1,
+            [1, 2, 3, 4].join("").charAt(0) + 1
+        );
+    }
+    expect: {
+        console.log(
+            "12341",
+            "11",
+            "21",
+            "11",
+            "21",
+            "11"
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_charAt_bad_index: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            "1234".charAt() + 1,
+            "1234".charAt("a") + 1,
+            "1234".charAt(3.14) + 1
+        );
+    }
+    expect: {
+        console.log(
+            "11",
+            "11",
+            "41"
+        );
+    }
+    expect_stdout: true
+}
+
+unsafe_charAt_noop: {
+    options = {
+        evaluate  : true,
+        unsafe    : true
+    }
+    input: {
+        console.log(
+            s.charAt(0),
+            "string".charAt(x)
+        );
+    }
+    expect: {
+        console.log(
+            s.charAt(0),
+            "string".charAt(x)
+        );
+    }
+}
+
+issue_1649: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        console.log(-1 + -1);
+    }
+    expect: {
+        console.log(-2);
+    }
+    expect_stdout: "-2";
+}

test/compress/expansions.js

@@ -0,0 +1,28 @@
+
+expand_arguments: {
+    input: {
+        func(a, ...rest);
+        func(...all);
+    }
+    expect_exact: "func(a,...rest);func(...all);"
+}
+
+expand_expression_arguments: {
+    input: {
+        f(...a.b);
+        f(...a.b());
+        f(...(a));
+        f(...(a.b));
+        f(...a[i]);
+    }
+    expect_exact: "f(...a.b);f(...a.b());f(...a);f(...a.b);f(...a[i]);"
+}
+
+expand_parameters: {
+    input: {
+        (function (a, ...b){});
+        (function (...args){});
+    }
+    expect_exact: "(function(a,...b){});(function(...args){});"
+}
+

test/compress/expression.js

@@ -0,0 +1,52 @@
+pow: {
+    input: {
+        var a = 2 ** 7;
+        var b = 3;
+        b **= 2;
+    }
+    expect: {
+        var a = 2 ** 7;
+        var b = 3;
+        b **= 2;
+    }
+}
+
+pow_with_number_constants: {
+    input: {
+        var a = 5 ** NaN;
+        var b = 42 ** +0;
+        var c = 42 ** -0;
+        var d = NaN ** 1;
+        var e = 2 ** Infinity;
+        var f = 2 ** -Infinity;
+    }
+    expect: {
+        var a = 5 ** NaN;
+        var b = 42 ** +0;
+        var c = 42 ** -0;
+        var d = NaN ** 1;
+        var e = 2 ** (1/0);
+        var f = 2 ** -(1/0);
+    }
+}
+
+pow_with_parentheses: {
+    input: {
+        var g = (-7) ** (0.5);
+        var h = 2324334 ** 34343443;
+        var i = (-2324334) ** 34343443;
+        var j = 2 ** (-3);
+        var k = 2.0 ** -3;
+        var l = 2.0 ** (5 - 7);
+    }
+    expect_exact: "var g=(-7)**.5;var h=2324334**34343443;var i=(-2324334)**34343443;var j=2**-3;var k=2**-3;var l=2**(5-7);"
+}
+
+pow_with_unary_between_brackets: {
+    input: {
+        var a = (-(+5)) ** 3;
+    }
+    expect: {
+        var a = (-+5)**3;
+    }
+}

test/compress/functions.js

@@ -0,0 +1,95 @@
+non_ascii_function_identifier_name: {
+    input: {
+        function fooλ(δλ) {}
+        function λ(δλ) {}
+        (function λ(δλ) {})()
+    }
+    expect_exact: "function fooλ(δλ){}function λ(δλ){}(function λ(δλ){})();"
+}
+
+iifes_returning_constants_keep_fargs_true: {
+    options = {
+        keep_fargs    : true,
+        side_effects  : true,
+        evaluate      : true,
+        unused        : true,
+        dead_code     : true,
+        conditionals  : true,
+        comparisons   : true,
+        booleans      : true,
+        if_return     : true,
+        join_vars     : true,
+        reduce_vars   : true,
+        cascade       : true,
+    }
+    input: {
+        (function(){ return -1.23; }());
+        console.log( function foo(){ return "okay"; }() );
+        console.log( function foo(x, y, z){ return 123; }() );
+        console.log( function(x, y, z){ return z; }() );
+        console.log( function(x, y, z){ if (x) return y; return z; }(1, 2, 3) );
+        console.log( function(x, y){ return x * y; }(2, 3) );
+        console.log( function(x, y){ return x * y; }(2, 3, a(), b()) );
+    }
+    expect: {
+        console.log("okay");
+        console.log(123);
+        console.log(void 0);
+        console.log(2);
+        console.log(6);
+        console.log((a(), b(), 6));
+    }
+    expect_stdout: true
+}
+
+iifes_returning_constants_keep_fargs_false: {
+    options = {
+        keep_fargs    : false,
+        side_effects  : true,
+        evaluate      : true,
+        unused        : true,
+        dead_code     : true,
+        conditionals  : true,
+        comparisons   : true,
+        booleans      : true,
+        if_return     : true,
+        join_vars     : true,
+        reduce_vars   : true,
+        cascade       : true,
+    }
+    input: {
+        (function(){ return -1.23; }());
+        console.log( function foo(){ return "okay"; }() );
+        console.log( function foo(x, y, z){ return 123; }() );
+        console.log( function(x, y, z){ return z; }() );
+        console.log( function(x, y, z){ if (x) return y; return z; }(1, 2, 3) );
+        console.log( function(x, y){ return x * y; }(2, 3) );
+        console.log( function(x, y){ return x * y; }(2, 3, a(), b()) );
+    }
+    expect: {
+        console.log("okay");
+        console.log(123);
+        console.log(void 0);
+        console.log(2);
+        console.log(6);
+        console.log((a(), b(), 6));
+    }
+    expect_stdout: true
+}
+
+issue_485_crashing_1530: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+    }
+    input: {
+        (function(a) {
+            if (true) return;
+            var b = 42;
+        })(this);
+    }
+    expect: {
+        this, void 0;
+    }
+}

test/compress/global_defs.js

@@ -0,0 +1,147 @@
+must_replace: {
+    options = {
+        global_defs: {
+            D: "foo bar",
+        }
+    }
+    input: {
+        console.log(D);
+    }
+    expect: {
+        console.log("foo bar");
+    }
+}
+
+keyword: {
+    options = {
+        global_defs: {
+            undefined: 0,
+            NaN: 1,
+            Infinity: 2,
+        },
+    }
+    input: {
+        console.log(undefined, NaN, Infinity);
+    }
+    expect: {
+        console.log(0, 1, 2);
+    }
+}
+
+object: {
+    options = {
+        evaluate: true,
+        global_defs: {
+            CONFIG: {
+                DEBUG: [ 0 ],
+                VALUE: 42,
+            },
+        },
+        unsafe: true,
+    }
+    input: {
+        function f(CONFIG) {
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return CONFIG.VALUE;
+        }
+        if (CONFIG.DEBUG[0])
+            console.debug("foo");
+    }
+    expect: {
+        function f(CONFIG) {
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return 42;
+        }
+        if (0)
+            console.debug("foo");
+    }
+}
+
+expanded: {
+    options = {
+        global_defs: {
+            "CONFIG.DEBUG": [ 0 ],
+            "CONFIG.VALUE": 42,
+        },
+    }
+    input: {
+        function f(CONFIG) {
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            // CONFIG not global - do not replace
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return CONFIG.VALUE;
+        }
+        if (CONFIG.DEBUG[0])
+            console.debug("foo");
+    }
+    expect: {
+        function f(CONFIG) {
+            return CONFIG.VALUE;
+        }
+        function g() {
+            var CONFIG = { VALUE: 1 };
+            return CONFIG.VALUE;
+        }
+        function h() {
+            return 42;
+        }
+        if ([0][0])
+            console.debug("foo");
+    }
+}
+
+mixed: {
+    options = {
+        evaluate: true,
+        global_defs: {
+            "CONFIG.VALUE": 42,
+            "FOO.BAR": "moo",
+        },
+        properties: true,
+    }
+    input: {
+        const FOO = { BAR: 0 };
+        console.log(FOO.BAR);
+        console.log(++CONFIG.DEBUG);
+        console.log(++CONFIG.VALUE);
+        console.log(++CONFIG["VAL" + "UE"]);
+        console.log(++DEBUG[CONFIG.VALUE]);
+        CONFIG.VALUE.FOO = "bar";
+        console.log(CONFIG);
+    }
+    expect: {
+        const FOO = { BAR: 0 };
+        console.log("moo");
+        console.log(++CONFIG.DEBUG);
+        console.log(++CONFIG.VALUE);
+        console.log(++CONFIG.VALUE);
+        console.log(++DEBUG[42]);
+        CONFIG.VALUE.FOO = "bar";
+        console.log(CONFIG);
+    }
+    expect_warnings: [
+        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:126,22]',
+        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:127,22]',
+        'WARN: global_defs CONFIG.VALUE redefined [test/compress/global_defs.js:129,8]',
+    ]
+}

test/compress/harmony.js

@@ -0,0 +1,342 @@
+arrow_function_parens: {
+    input: {
+        something && (() => {});
+    }
+    expect_exact: "something&&(()=>{});"
+}
+arrow_function_parens_2: {
+    input: {
+        (() => null)();
+    }
+    expect_exact: "(()=>null)();"
+}
+
+typeof_arrow_functions: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var foo = typeof (x) => null;
+    }
+    expect_exact: "var foo=\"function\";"
+}
+
+classes: {
+    input: {
+        class SomeClass {
+            constructor() {
+            };
+            foo() {};
+        };
+        class NoSemi {
+            constructor(...args) {
+            }
+            foo() {}
+        };
+        class ChildClass extends SomeClass {};
+        var asExpression = class AsExpression {};
+        var nameless = class {};
+    }
+    expect_exact: "class SomeClass{constructor(){}foo(){}}class NoSemi{constructor(...args){}foo(){}}class ChildClass extends SomeClass{}var asExpression=class AsExpression{};var nameless=class{};"
+}
+
+class_statics: {
+    input: {
+        x = class {
+            static staticMethod() {}
+            static get foo() {}
+            static set bar() {}
+            static() { /* "static" can be a method name! */ }
+            get() { /* "get" can be a method name! */ }
+            set() { /* "set" can be a method name! */ }
+        }
+    }
+    expect_exact: "x=class{static staticMethod(){}static get foo(){}static set bar(){}static(){}get(){}set(){}};"
+}
+
+class_name_can_be_mangled: {
+    mangle = { };
+    input: {
+        function x() {
+            class Foo {
+            }
+            var class1 = Foo
+            var class2 = class Bar {}
+        }
+    }
+    expect: {
+        function x() {
+            class a { }
+            var n = a
+            var r = class a {}
+        }
+    }
+}
+
+class_name_can_be_preserved: {
+    mangle = {
+        keep_classnames: true
+    }
+    input: {
+        function x() {
+            (class Baz { });
+            class Foo {};
+        }
+    }
+    expect: {
+        function x() {
+            (class Baz { });
+            class Foo {};
+        }
+    }
+}
+
+classes_can_have_generators: {
+    input: {
+        class Foo {
+            *bar() {}
+            static *baz() {}
+        }
+    }
+    expect: {
+        class Foo {
+            *bar() {}
+            static *baz() {}
+        }
+    }
+}
+
+classes_can_have_computed_generators: {
+    input: {
+        class C4 {
+            *['constructor']() {}
+        }
+    }
+    expect: {
+        class C4 {
+            *['constructor']() {}
+        }
+    }
+}
+
+classes_can_have_computed_static: {
+    input: {
+        class C4 {
+            static ['constructor']() {}
+        }
+    }
+    expect: {
+        class C4 {
+            static ['constructor']() {}
+        }
+    }
+}
+
+class_methods_and_getters_with_keep_quoted_props_enabled: {
+    beautify = {
+        quote_style: 3,
+        keep_quoted_props: true,
+    }
+    input: {
+        class clss {
+            a() {}
+            "b"() {}
+            get c() { return "c"}
+            get "d"() { return "d"}
+            set e(a) { doSomething(a); }
+            set 'f'(a) { doSomething(b); }
+            static g() {}
+            static "h"() {}
+        }
+    }
+    expect_exact: 'class clss{a(){}"b"(){}get c(){return"c"}get"d"(){return"d"}set e(a){doSomething(a)}set\'f\'(a){doSomething(b)}static g(){}static"h"(){}}'
+}
+
+new_target: {
+    input: {
+        new.target;
+        new.target.name;
+    }
+    expect_exact: "new.target;new.target.name;"
+}
+
+number_literals: {
+    input: {
+        0b1001;
+        0B1001;
+        0o11;
+        0O11;
+    }
+
+    expect: {
+        9;
+        9;
+        9;
+        9;
+    }
+}
+
+import_statement: {
+    input: {
+        import "mod-name";
+        import Foo from "bar";
+        import { Bar, Baz } from 'lel';
+        import Bar, { Foo } from 'lel';
+        import { Bar as kex, Baz as food } from 'lel';
+    }
+    expect_exact: "import\"mod-name\";import Foo from\"bar\";import{Bar,Baz}from\"lel\";import Bar,{Foo}from\"lel\";import{Bar as kex,Baz as food}from\"lel\";"
+}
+
+export_statement: {
+    input: {
+        export default 1;
+        export var foo = 4;
+        export let foo = 6;
+        export const foo = 6;
+        export function foo() {};
+        export class foo { };
+    }
+    expect_exact: "export default 1;export var foo=4;export let foo=6;export const foo=6;export function foo(){};export class foo{};"
+}
+
+export_module_statement: {
+    input: {
+        export * from "a.js";
+        export {A} from "a.js";
+        export {A, B} from "a.js";
+    }
+    expect_exact: 'export*from"a.js";export{A}from"a.js";export{A,B}from"a.js";'
+}
+
+import_statement_mangling: {
+    mangle = { toplevel: true };
+    input: {
+        import Foo from "foo";
+        import Bar, {Food} from "lel";
+        import {What as Whatever} from "lel";
+        Foo();
+        Bar();
+        Food();
+        Whatever();
+    }
+    expect: {
+        import l from "foo";
+        import e, {Food as o} from "lel";
+        import {What as f} from "lel";
+        l();
+        e();
+        o();
+        f();
+    }
+}
+
+export_statement_mangling: {
+    mangle = { };
+    input: {
+        export var foo = 6;
+        export function bar() { }
+        export class Baz { }
+        bar(foo, Baz)
+    }
+    expect: {
+        export var foo = 6;
+        export function bar() { }
+        export class Baz { }
+        bar(foo, Baz)
+    }
+}
+
+// https://github.com/mishoo/UglifyJS2/issues/1021
+regression_for_of_const: {
+    input: {
+        for (const x of y) {}
+        for (const x in y) {}
+    }
+    expect: {
+        for (const x of y);for (const x in y);
+    }
+}
+
+// Fabio: My patches accidentally caused a crash whenever
+// there's an extraneous set of parens around an object.
+regression_cannot_destructure: {
+    input: {
+        var x = ({ x : 3 });
+        x(({ x: 3 }));
+    }
+    expect_exact: "var x={x:3};x({x:3});";
+}
+
+regression_cannot_use_of: {
+    input: {
+        function of() {
+        }
+        var of = "is a valid variable name";
+        of = { of: "is ok" };
+        x.of;
+        of: foo()
+    }
+    expect: {
+        function of(){}
+        var of="is a valid variable name";
+        of={of:"is ok"};
+        x.of;
+        foo();  /* Label statement missing? No prob. */
+    }
+}
+
+fat_arrow_as_param: {
+    input: {
+        foo(x => x);
+        foo(x => x, y => y);
+
+        foo(x => (x, x));
+        foo(x => (x, x), y => (y, y));
+    }
+    expect_exact: "foo(x=>x);foo(x=>x,y=>y);foo(x=>(x,x));foo(x=>(x,x),y=>(y,y));"
+}
+
+default_assign: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        function f(a, b = 3) {
+            console.log(a);
+        }
+    }
+    expect: {
+        function f(a) {
+            console.log(a);
+        }
+    }
+}
+
+expansion: {
+    options = {
+        keep_fargs: false,
+        unused: true,
+    }
+    input: {
+        function f(a, ...b) {
+            console.log(a);
+        }
+    }
+    expect: {
+        function f(a) {
+            console.log(a);
+        }
+    }
+}
+
+issue_1613: {
+  mangle = { toplevel: true };
+  input: {
+    const name = 1;
+    const foo = {
+      name
+    };
+  }
+  expect_exact: "const n=1;const c={name:n};"
+}

test/compress/hoist.js

@@ -0,0 +1,85 @@
+
+hoist_vars: {
+    options = {
+        hoist_vars: true
+    }
+    input: {
+        function a() {
+            bar();
+            var var1;
+            var var2;
+        }
+        function b(anArg) {
+            bar();
+            var var1;
+            var anArg;
+        }
+    }
+    expect: {
+        function a() {
+            var var1, var2;  // Vars go up and are joined
+            bar();
+        }
+        function b(anArg) {
+            var var1;
+            bar();
+            // But vars named like arguments go away!
+        }
+    }
+}
+
+hoist_funs: {
+    options = {
+        hoist_funs: true
+    }
+    input: {
+        function a() {
+            bar();
+            function foo() {}
+        }
+    }
+    expect: {
+        function a() {
+            function foo() {}  // Funs go up
+            bar();
+        }
+    }
+}
+
+hoist_no_destructurings: {
+    options = {
+        hoist_vars: true,
+        hoist_funs: true
+    }
+    input: {
+        function a([anArg]) {
+            bar();
+            var var1;
+            var anArg;  // Because anArg is already declared, this goes away!
+        }
+    }
+    expect: {
+        function a([anArg]) {
+            var var1;
+            bar();
+        }
+    }
+}
+
+dont_hoist_var_destructurings: {
+    options = {
+        hoist_vars: true,
+        hoist_funs: true
+    }
+    input: {
+        function x() {
+            // If foo is null or undefined, this should be an exception
+            var {x,y} = foo;
+        }
+    }
+    expect: {
+        function x() {
+            var {x,y} = foo;
+        }
+    }
+}

test/compress/hoist_vars.js

@@ -0,0 +1,90 @@
+statements: {
+    options = {
+        hoist_funs: false,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1;
+            var b = 2;
+            var c = 3;
+            function g() {}
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            var a = 1, b = 2, c = 3;
+            function g() {}
+            return g(a, b, c);
+        }
+    }
+}
+
+statements_funs: {
+    options = {
+        hoist_funs: true,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1;
+            var b = 2;
+            var c = 3;
+            function g() {}
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            var a = 1, b = 2, c = 3;
+            return g(a, b, c);
+        }
+    }
+}
+
+sequences: {
+    options = {
+        hoist_funs: false,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1, b = 2;
+            function g() {}
+            var c = 3;
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            var c, a = 1, b = 2;
+            function g() {}
+            c = 3;
+            return g(a, b, c);
+        }
+    }
+}
+
+sequences_funs: {
+    options = {
+        hoist_funs: true,
+        hoist_vars: true,
+    }
+    input: {
+        function f() {
+            var a = 1, b = 2;
+            function g() {}
+            var c = 3;
+            return g(a, b, c);
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            var a = 1, b = 2, c = 3;
+            return g(a, b, c);
+        }
+    }
+}

test/compress/html_comments.js

@@ -0,0 +1,64 @@
+html_comment_in_expression: {
+    input: {
+        function f(a, b, x, y) { return a < !--b && x-- > y; }
+    }
+    expect_exact: "function f(a,b,x,y){return a< !--b&&x-- >y}";
+}
+
+html_comment_in_less_than: {
+    input: {
+        function f(a, b) { return a < !--b; }
+    }
+    expect_exact: "function f(a,b){return a< !--b}";
+}
+
+html_comment_in_left_shift: {
+    input: {
+        function f(a, b) { return a << !--b; }
+    }
+    expect_exact: "function f(a,b){return a<< !--b}";
+}
+
+html_comment_in_right_shift: {
+    input: {
+        function f(a, b) { return a-- >> b; }
+    }
+    expect_exact: "function f(a,b){return a-- >>b}";
+}
+
+html_comment_in_zero_fill_right_shift: {
+    input: {
+        function f(a, b) { return a-- >>> b; }
+    }
+    expect_exact: "function f(a,b){return a-- >>>b}";
+}
+
+html_comment_in_greater_than: {
+    input: {
+        function f(a, b) { return a-- > b; }
+    }
+    expect_exact: "function f(a,b){return a-- >b}";
+}
+
+html_comment_in_greater_than_or_equal: {
+    input: {
+        function f(a, b) { return a-- >= b; }
+    }
+    expect_exact: "function f(a,b){return a-- >=b}";
+}
+
+html_comment_in_string_literal: {
+    input: {
+        function f() { return "<!--HTML-->comment in<!--string literal-->"; }
+    }
+    expect_exact: 'function f(){return"\\x3c!--HTML--\\x3ecomment in\\x3c!--string literal--\\x3e"}';
+}
+
+html_comment_after_multiline_comment: {
+    input: {
+        var foo; /*
+*/-->   var bar;
+        var foobar;
+    }
+    expect_exact: "var foo;var foobar;"
+}

test/compress/if_return.js

@@ -0,0 +1,304 @@
+if_return_1: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f(x) {
+            if (x) {
+                return true;
+            }
+        }
+    }
+    expect: {
+        function f(x){if(x)return!0}
+    }
+}
+
+if_return_2: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f(x, y) {
+            if (x)
+                return 3;
+            if (y)
+                return c();
+        }
+    }
+    expect: {
+        function f(x,y){return x?3:y?c():void 0}
+    }
+}
+
+if_return_3: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f(x) {
+            a();
+            if (x) {
+                b();
+                return false;
+            }
+        }
+    }
+    expect: {
+        function f(x){if(a(),x)return b(),!1}
+    }
+}
+
+if_return_4: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f(x, y) {
+            a();
+            if (x) return 3;
+            b();
+            if (y) return c();
+        }
+    }
+    expect: {
+        function f(x,y){return a(),x?3:(b(),y?c():void 0)}
+    }
+}
+
+if_return_5: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f() {
+            if (x)
+                return;
+            return 7;
+            if (y)
+                return j;
+        }
+    }
+    expect: {
+        function f(){if(!x)return 7}
+    }
+}
+
+if_return_6: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f(x) {
+          return x ? true : void 0;
+          return y;
+        }
+    }
+    expect: {
+        // suboptimal
+        function f(x){return!!x||void 0}
+    }
+}
+
+if_return_7: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function f(x) {
+            if (x) {
+                return true;
+            }
+            foo();
+            bar();
+        }
+    }
+    expect: {
+        function f(x){if(x)return!0;foo(),bar()}
+    }
+}
+
+if_return_8: {
+    options = {
+        if_return:     true,
+        sequences:     true,
+        conditionals:  true,
+        side_effects : true,
+    }
+    input: {
+        function f(e) {
+            if (2 == e) return foo();
+            if (3 == e) return bar();
+            if (4 == e) return baz();
+            fail(e);
+        }
+
+        function g(e) {
+            if (a(e)) return foo();
+            if (b(e)) return bar();
+            if (c(e)) return baz();
+            fail(e);
+        }
+
+        function h(e) {
+            if (a(e)) return foo();
+            else if (b(e)) return bar();
+            else if (c(e)) return baz();
+            else fail(e);
+        }
+
+        function i(e) {
+            if (a(e)) return foo();
+            else if (b(e)) return bar();
+            else if (c(e)) return baz();
+            fail(e);
+        }
+    }
+    expect: {
+        function f(e){return 2==e?foo():3==e?bar():4==e?baz():void fail(e)}
+        function g(e){return a(e)?foo():b(e)?bar():c(e)?baz():void fail(e)}
+        function h(e){return a(e)?foo():b(e)?bar():c(e)?baz():void fail(e)}
+        function i(e){return a(e)?foo():b(e)?bar():c(e)?baz():void fail(e)}
+    }
+}
+
+issue_1089: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : true,
+        comparisons  : true,
+        evaluate     : true,
+        booleans     : true,
+        unused       : true,
+        side_effects : true,
+        dead_code    : true,
+    }
+    input: {
+        function x() {
+            var f = document.getElementById("fname");
+            if (f.files[0].size > 12345) {
+                alert("alert");
+                f.focus();
+                return false;
+            }
+        }
+    }
+    expect: {
+        function x() {
+            var f = document.getElementById("fname");
+            if (f.files[0].size > 12345)
+                return alert("alert"), f.focus(), !1;
+        }
+    }
+}
+
+issue_1437: {
+    options = {
+        if_return    : true,
+        sequences    : true,
+        conditionals : false
+    }
+    input: {
+        function x() {
+            if (a())
+                return b();
+            if (c())
+                return d();
+            else
+                e();
+            f();
+        }
+    }
+    expect: {
+        function x() {
+            if (a())
+                return b();
+            if (c())
+                return d();
+            else
+                e()
+            f();
+        }
+    }
+}
+
+issue_1437_conditionals: {
+    options = {
+        conditionals : true,
+        if_return    : true,
+        sequences    : true
+    }
+    input: {
+        function x() {
+            if (a())
+                return b();
+            if (c())
+                return d();
+            else
+                e();
+            f();
+        }
+    }
+    expect: {
+        function x() {
+            return a() ? b() : c() ? d() : (e(), f(), void 0);
+        }
+    }
+}

test/compress/issue-1001.js

@@ -0,0 +1,8 @@
+parenthesis_strings_in_parenthesis: {
+    input: {
+        var foo = ('(');
+        a(')');
+
+    }
+    expect_exact: 'var foo="(";a(")");'
+}

test/compress/issue-1034.js

@@ -0,0 +1,118 @@
+non_hoisted_function_after_return: {
+    options = {
+        hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
+        evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
+        if_return: true, join_vars: true, cascade: true, side_effects: true
+    }
+    input: {
+        function foo(x) {
+            if (x) {
+                return bar();
+                not_called1();
+            } else {
+                return baz();
+                not_called2();
+            }
+            function bar() { return 7; }
+            return not_reached;
+            function UnusedFunction() {}
+            function baz() { return 8; }
+        }
+    }
+    expect: {
+        function foo(x) {
+            return x ? bar() : baz();
+            function bar() { return 7 }
+            function baz() { return 8 }
+        }
+    }
+    expect_warnings: [
+        'WARN: Dropping unreachable code [test/compress/issue-1034.js:11,16]',
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:14,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:17,12]",
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:18,21]"
+    ]
+}
+
+non_hoisted_function_after_return_2a: {
+    options = {
+        hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
+        evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
+        if_return: true, join_vars: true, cascade: true, side_effects: true,
+        collapse_vars: false, passes: 2, warnings: "verbose"
+    }
+    input: {
+        function foo(x) {
+            if (x) {
+                return bar(1);
+                var a = not_called(1);
+            } else {
+                return bar(2);
+                var b = not_called(2);
+            }
+            var c = bar(3);
+            function bar(x) { return 7 - x; }
+            function nope() {}
+            return b || c;
+        }
+    }
+    expect: {
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) {
+                return 7 - x;
+            }
+        }
+    }
+    expect_warnings: [
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:48,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:48,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:51,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:51,16]",
+        "WARN: Dropping unused variable a [test/compress/issue-1034.js:48,20]",
+        "WARN: Dropping unused function nope [test/compress/issue-1034.js:55,21]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:53,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:53,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:56,12]",
+        "WARN: Dropping unused variable b [test/compress/issue-1034.js:51,20]",
+        "WARN: Dropping unused variable c [test/compress/issue-1034.js:53,16]",
+    ]
+}
+
+non_hoisted_function_after_return_2b: {
+    options = {
+        hoist_funs: false, dead_code: true, conditionals: true, comparisons: true,
+        evaluate: true, booleans: true, loops: true, unused: true, keep_fargs: true,
+        if_return: true, join_vars: true, cascade: true, side_effects: true,
+        collapse_vars: false
+    }
+    input: {
+        function foo(x) {
+            if (x) {
+                return bar(1);
+            } else {
+                return bar(2);
+                var b;
+            }
+            var c = bar(3);
+            function bar(x) {
+                return 7 - x;
+            }
+            return b || c;
+        }
+    }
+    expect: {
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) { return 7 - x; }
+        }
+    }
+    expect_warnings: [
+        // duplicate warnings no longer emitted
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:95,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:95,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:97,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:97,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:101,12]",
+    ]
+}

test/compress/issue-1041.js

@@ -0,0 +1,41 @@
+const_declaration: {
+    options = {
+        evaluate: true
+    };
+
+    input: {
+        const goog = goog || {};
+    }
+    expect: {
+        const goog = goog || {};
+    }
+}
+
+const_pragma: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    };
+
+    input: {
+        /** @const */ var goog = goog || {};
+    }
+    expect: {
+        var goog = goog || {};
+    }
+}
+
+// for completeness' sake
+not_const: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    };
+
+    input: {
+        var goog = goog || {};
+    }
+    expect: {
+        var goog = goog || {};
+    }
+}

test/compress/issue-1043.js

@@ -0,0 +1,30 @@
+issue_1043: {
+    options = {
+        side_effects: true
+    };
+
+    input: {
+        function* range(start = 0, end = null, step = 1) {
+            if (end == null) {
+                end = start;
+                start = 0;
+            }
+
+            for (let i = start; i < end; i += step) {
+                yield i;
+            }
+        }
+    }
+
+    expect: {
+        function* range(start = 0, end = null, step = 1) {
+            if (null == end) {
+                end = start;
+                start = 0;
+            }
+
+            for (let i = start; i < end; i += step)
+                yield i;
+        }
+    }
+}

test/compress/issue-1044.js

@@ -0,0 +1,9 @@
+issue_1044: {
+    options = { evaluate: true, conditionals: true };
+    input: {
+        const mixed = Base ? class extends Base {} : class {}
+    }
+    expect: {
+        const mixed = Base ? class extends Base {} : class {}
+    }
+}

test/compress/issue-1052.js

@@ -0,0 +1,96 @@
+multiple_functions: {
+    options = { if_return: true, hoist_funs: false };
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+
+            function f() {}
+            function g() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            function f() {}
+            function g() {}
+
+            // NOTE: other compression steps will reduce this
+            // down to just `window`.
+            if ( window );
+        } )();
+    }
+}
+
+single_function: {
+    options = { if_return: true, hoist_funs: false };
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+
+            function f() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            function f() {}
+
+            if ( window );
+        } )();
+    }
+}
+
+deeply_nested: {
+    options = { if_return: true, hoist_funs: false };
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+
+            function f() {}
+            function g() {}
+
+            if ( !document ) {
+                return;
+            }
+
+            function h() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            function f() {}
+            function g() {}
+
+            function h() {}
+
+            // NOTE: other compression steps will reduce this
+            // down to just `window`.
+            if ( window )
+                if (document);
+        } )();
+    }
+}
+
+not_hoisted_when_already_nested: {
+    options = { if_return: true, hoist_funs: false };
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+
+            if ( foo ) function f() {}
+
+        } )();
+    }
+    expect: {
+        ( function() {
+            if ( window )
+                if ( foo ) function f() {}
+        } )();
+    }
+}

test/compress/issue-1105.js

@@ -0,0 +1,240 @@
+with_in_global_scope: {
+    options = {
+        unused: true
+    }
+    input: {
+        var o = 42;
+        with(o) {
+            var foo = 'something'
+        }
+        doSomething(o);
+    }
+    expect: {
+        var o=42;
+        with(o)
+            var foo = "something";
+        doSomething(o);
+    }
+}
+with_in_function_scope: {
+    options = {
+        unused: true
+    }
+    input: {
+        function foo() {
+            var o = 42;
+            with(o) {
+                var foo = "something"
+            }
+            doSomething(o);
+        }
+    }
+    expect: {
+        function foo() {
+            var o=42;
+            with(o)
+                var foo = "something";
+            doSomething(o)
+        }
+    }
+}
+compress_with_with_in_other_scope: {
+    options = {
+        unused: true
+    }
+    input: {
+        function foo() {
+            var o = 42;
+            with(o) {
+                var foo = "something"
+            }
+            doSomething(o);
+        }
+        function bar() {
+            var unused = 42;
+            return something();
+        }
+    }
+    expect: {
+        function foo() {
+            var o = 42;
+            with(o)
+                var foo = "something";
+            doSomething(o)
+        }
+        function bar() {
+            return something()
+        }
+    }
+}
+with_using_existing_variable_outside_scope: {
+    options = {
+        unused: true
+    }
+    input: {
+        function f() {
+            var o = {};
+            var unused = {}; // Doesn't get removed because upper scope uses with
+            function foo() {
+                with(o) {
+                    var foo = "something"
+                }
+                doSomething(o);
+            }
+            foo()
+        }
+    }
+    expect: {
+        function f() {
+            var o = {};
+            var unused = {};
+            function foo() {
+                with(o)
+                    var foo = "something";
+                doSomething(o)
+            }
+            foo()
+        }
+    }
+}
+check_drop_unused_in_peer_function: {
+    options = {
+        unused: true
+    }
+    input: {
+        function outer() {
+            var o = {};
+            var unused = {};     // should be kept
+            function foo() {     // should be kept
+                function not_in_use() {
+                    var nested_unused = "foo"; // should be dropped
+                    return 24;
+                }
+                var unused = {}; // should be kept
+                with (o) {
+                    var foo = "something";
+                }
+                doSomething(o);
+            }
+            function bar() {
+                var unused = {}; // should be dropped
+                doSomethingElse();
+            }
+            foo();
+            bar();
+        }
+    }
+    expect: {
+        function outer() {
+            var o = {};
+            var unused = {};     // should be kept
+            function foo() {     // should be kept
+                function not_in_use() {
+                    return 24;
+                }
+                var unused = {}; // should be kept
+                with (o)
+                    var foo = "something";
+                doSomething(o);
+            }
+            function bar() {
+                doSomethingElse();
+            }
+            foo();
+            bar();
+        }
+    }
+}
+
+Infinity_not_in_with_scope: {
+    options = {
+        unused: true
+    }
+    input: {
+        var o = { Infinity: 'oInfinity' };
+        var vInfinity = "Infinity";
+        vInfinity = Infinity;
+    }
+    expect: {
+        var o = { Infinity: 'oInfinity' }
+        var vInfinity = "Infinity"
+        vInfinity = 1/0
+    }
+}
+
+Infinity_in_with_scope: {
+    options = {
+        unused: true
+    }
+    input: {
+        var o = { Infinity: 'oInfinity' };
+        var vInfinity = "Infinity";
+        with (o) { vInfinity = Infinity; }
+    }
+    expect: {
+        var o = { Infinity: 'oInfinity' }
+        var vInfinity = "Infinity"
+        with (o) vInfinity = Infinity
+    }
+}
+
+assorted_Infinity_NaN_undefined_in_with_scope: {
+    options = {
+        unused:        true,
+        evaluate:      true,
+        dead_code:     true,
+        conditionals:  true,
+        comparisons:   true,
+        booleans:      true,
+        hoist_funs:    true,
+        keep_fargs:    true,
+        if_return:     true,
+        join_vars:     true,
+        cascade:       true,
+        side_effects:  true,
+        sequences:     false,
+    }
+    input: {
+        var o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5,
+        }
+        if (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(2 + 7 + undefined, 2 + 7 + void 0);
+        }
+    }
+    expect: {
+        var o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5
+        }
+        if (o) {
+            f(void 0, void 0);
+            f(NaN, NaN);
+            f(1/0, 1/0);
+            f(-(1/0), -(1/0));
+            f(NaN, NaN);
+        }
+        with (o) {
+            f(undefined, void 0);
+            f(NaN, 0/0);
+            f(Infinity, 1/0);
+            f(-Infinity, -(1/0));
+            f(9 + undefined, 9 + void 0);
+        }
+    }
+}
+

test/compress/issue-12.js

@@ -9,3 +9,50 @@ keep_name_of_setter: {
     input: { a = { set foo () {} } }
     expect: { a = { set foo () {} } }
 }
+
+setter_with_operator_keys: {
+    input: {
+        var tokenCodes  = {
+            get instanceof(){
+                return test0;
+            },
+            set instanceof(value){
+                test0 = value;
+            },
+            set typeof(value){
+                test1 = value;
+            },
+            get typeof(){
+                return test1;
+            },
+            set else(value){
+                test2 = value;
+            },
+            get else(){
+                return test2;
+            }
+        };
+    }
+    expect: {
+        var tokenCodes  = {
+            get instanceof(){
+                return test0;
+            },
+            set instanceof(value){
+                test0 = value;
+            },
+            set typeof(value){
+                test1 = value;
+            },
+            get typeof(){
+                return test1;
+            },
+            set else(value){
+                test2 = value;
+            },
+            get else(){
+                return test2;
+            }
+        };
+    }
+}

test/compress/issue-1202.js

@@ -0,0 +1,51 @@
+mangle_keep_fnames_false: {
+    options = {
+        keep_fnames : true,
+        keep_fargs  : true,
+    }
+    mangle = {
+        keep_fnames : false,
+    }
+    input: {
+        "use strict";
+        function total() {
+            return function n(a, b, c) {
+                return a + b + c;
+            };
+        }
+    }
+    expect: {
+        "use strict";
+        function total() {
+            return function t(n, r, u) {
+                return n + r + u;
+            };
+        }
+    }
+}
+
+mangle_keep_fnames_true: {
+    options = {
+        keep_fnames : true,
+        keep_fargs  : true,
+    }
+    mangle = {
+        keep_fnames : true,
+    }
+    input: {
+        "use strict";
+        function total() {
+            return function n(a, b, c) {
+                return a + b + c;
+            };
+        }
+    }
+    expect: {
+        "use strict";
+        function total() {
+            return function n(t, r, u) {
+                return t + r + u;
+            };
+        }
+    }
+}

test/compress/issue-1212.js

@@ -0,0 +1,76 @@
+issue_1212_debug_false: {
+    options = {
+        global_defs   : { DEBUG: false },
+        sequences     : true,
+        properties    : true,
+        dead_code     : true,
+        conditionals  : true,
+        comparisons   : true,
+        evaluate      : true,
+        booleans      : true,
+        loops         : true,
+        unused        : true,
+        hoist_funs    : true,
+        keep_fargs    : true,
+        if_return     : true,
+        join_vars     : true,
+        cascade       : true,
+        side_effects  : true,
+    }
+    input: {
+        class foo {
+            bar() {
+                if (DEBUG)
+                    console.log("DEV");
+                else
+                    console.log("PROD");
+            }
+        }
+        new foo().bar();
+    }
+    expect: {
+        class foo{
+            bar() { console.log("PROD") }
+        }
+        (new foo).bar();
+    }
+}
+
+issue_1212_debug_true: {
+    options = {
+        global_defs   : { DEBUG: true },
+        sequences     : true,
+        properties    : true,
+        dead_code     : true,
+        conditionals  : true,
+        comparisons   : true,
+        evaluate      : true,
+        booleans      : true,
+        loops         : true,
+        unused        : true,
+        hoist_funs    : true,
+        keep_fargs    : true,
+        if_return     : true,
+        join_vars     : true,
+        cascade       : true,
+        side_effects  : true,
+    }
+    input: {
+        class foo {
+            bar() {
+                if (DEBUG)
+                    console.log("DEV");
+                else
+                    console.log("PROD");
+            }
+        }
+        new foo().bar();
+    }
+    expect: {
+        class foo{
+            bar() { console.log("DEV") }
+        }
+        (new foo).bar();
+    }
+}
+

test/compress/issue-126.js

@@ -0,0 +1,24 @@
+concatenate_rhs_strings: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        foo(bar() + 123 + "Hello" + "World");
+        foo(bar() + (123 + "Hello") + "World");
+        foo((bar() + 123) + "Hello" + "World");
+        foo(bar() + 123 + "Hello" + "World" + ("Foo" + "Bar"));
+        foo("Foo" + "Bar" + bar() + 123 + "Hello" + "World" + ("Foo" + "Bar"));
+        foo("Hello" + bar() + 123 + "World");
+        foo(bar() + 'Foo' + (10 + parseInt('10')));
+    }
+    expect: {
+        foo(bar() + 123 + "HelloWorld");
+        foo(bar() + "123HelloWorld");
+        foo((bar() + 123) + "HelloWorld");
+        foo(bar() + 123 + "HelloWorldFooBar");
+        foo("FooBar" + bar() + "123HelloWorldFooBar");
+        foo("Hello" + bar() + "123World");
+        foo(bar() + 'Foo' + (10 + parseInt('10')));
+    }
+}

test/compress/issue-1261.js

@@ -0,0 +1,176 @@
+pure_function_calls: {
+    options = {
+        evaluate     : true,
+        conditionals : true,
+        comparisons  : true,
+        side_effects : true,
+        booleans     : true,
+        unused       : true,
+        if_return    : true,
+        join_vars    : true,
+        cascade      : true,
+        negate_iife  : true,
+    }
+    input: {
+        // pure top-level IIFE will be dropped
+        // @__PURE__ - comment
+        (function() {
+            console.log("iife0");
+        })();
+
+        // pure top-level IIFE assigned to unreferenced var will not be dropped
+        var iife1 = /*@__PURE__*/(function() {
+            console.log("iife1");
+            function iife1() {}
+            return iife1;
+        })();
+
+        (function(){
+            // pure IIFE in function scope assigned to unreferenced var will be dropped
+            var iife2 = /*#__PURE__*/(function() {
+                console.log("iife2");
+                function iife2() {}
+                return iife2;
+            })();
+        })();
+
+        // comment #__PURE__ comment
+        bar(), baz(), quux();
+        a.b(), /* @__PURE__ */ c.d.e(), f.g();
+    }
+    expect: {
+        var iife1 = function() {
+            console.log("iife1");
+            function iife1() {}
+            return iife1;
+        }();
+
+        baz(), quux();
+        a.b(), f.g();
+    }
+    expect_warnings: [
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:17,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:17,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:30,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:30,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:28,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:38,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:39,31]",
+    ]
+}
+
+pure_function_calls_toplevel: {
+    options = {
+        evaluate     : true,
+        conditionals : true,
+        comparisons  : true,
+        side_effects : true,
+        booleans     : true,
+        unused       : true,
+        if_return    : true,
+        join_vars    : true,
+        cascade      : true,
+        negate_iife  : true,
+        toplevel     : true,
+    }
+    input: {
+        // pure top-level IIFE will be dropped
+        // @__PURE__ - comment
+        (function() {
+            console.log("iife0");
+        })();
+
+        // pure top-level IIFE assigned to unreferenced var will be dropped
+        var iife1 = /*@__PURE__*/(function() {
+            console.log("iife1");
+            function iife1() {}
+            return iife1;
+        })();
+
+        (function(){
+            // pure IIFE in function scope assigned to unreferenced var will be dropped
+            var iife2 = /*#__PURE__*/(function() {
+                console.log("iife2");
+                function iife2() {}
+                return iife2;
+            })();
+        })();
+
+        // comment #__PURE__ comment
+        bar(), baz(), quux();
+        a.b(), /* @__PURE__ */ c.d.e(), f.g();
+    }
+    expect: {
+        baz(), quux();
+        a.b(), f.g();
+    }
+    expect_warnings: [
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:79,8]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:79,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:92,37]",
+        "WARN: Dropping unused variable iife2 [test/compress/issue-1261.js:92,16]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:90,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:100,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:101,31]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:84,33]",
+        "WARN: Dropping unused variable iife1 [test/compress/issue-1261.js:84,12]",
+    ]
+}
+
+should_warn: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        /* @__PURE__ */(function(){x})(), void/* @__PURE__ */(function(){y})();
+        /* @__PURE__ */(function(){x})() || true ? foo() : bar();
+        true || /* @__PURE__ */(function(){y})() ? foo() : bar();
+        /* @__PURE__ */(function(){x})() && false ? foo() : bar();
+        false && /* @__PURE__ */(function(){y})() ? foo() : bar();
+        /* @__PURE__ */(function(){x})() + "foo" ? bar() : baz();
+        "foo" + /* @__PURE__ */(function(){y})() ? bar() : baz();
+        /* @__PURE__ */(function(){x})() ? foo() : foo();
+        [/* @__PURE__ */(function(){x})()] ? foo() : bar();
+        !{ foo: /* @__PURE__ */(function(){x})() } ? bar() : baz();
+    }
+    expect: {
+        foo();
+        foo();
+        bar();
+        bar();
+        bar();
+        bar();
+        foo();
+        foo();
+        baz();
+    }
+    expect_warnings: [
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,61]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:128,23]",
+        "WARN: Dropping side-effect-free statement [test/compress/issue-1261.js:128,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:129,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:129,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:129,23]",
+        "WARN: Boolean || always true [test/compress/issue-1261.js:130,8]",
+        "WARN: Condition always true [test/compress/issue-1261.js:130,8]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:131,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:131,23]",
+        "WARN: Condition always false [test/compress/issue-1261.js:131,23]",
+        "WARN: Boolean && always false [test/compress/issue-1261.js:132,8]",
+        "WARN: Condition always false [test/compress/issue-1261.js:132,8]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:133,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:133,23]",
+        "WARN: Condition always true [test/compress/issue-1261.js:133,23]",
+        "WARN: + in boolean context always true [test/compress/issue-1261.js:134,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:134,31]",
+        "WARN: Condition always true [test/compress/issue-1261.js:134,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:135,23]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:136,24]",
+        "WARN: Condition always true [test/compress/issue-1261.js:136,8]",
+        "WARN: Dropping __PURE__ call [test/compress/issue-1261.js:137,31]",
+        "WARN: Condition always false [test/compress/issue-1261.js:137,8]",
+    ]
+}

test/compress/issue-1275.js

@@ -0,0 +1,50 @@
+string_plus_optimization: {
+    options = {
+        side_effects  : true,
+        evaluate      : true,
+        conditionals  : true,
+        comparisons   : true,
+        dead_code     : true,
+        booleans      : true,
+        unused        : true,
+        if_return     : true,
+        join_vars     : true,
+        cascade       : true,
+        hoist_funs    : true,
+    };
+    input: {
+        function foo(anything) {
+            function throwing_function() {
+                throw "nope";
+            }
+            try {
+                console.log('0' + throwing_function() ? "yes" : "no");
+            } catch (ex) {
+                console.log(ex);
+            }
+            console.log('0' + anything ? "yes" : "no");
+            console.log(anything + '0' ? "Yes" : "No");
+            console.log('' + anything);
+            console.log(anything + '');
+        }
+        foo();
+    }
+    expect: {
+        function foo(anything) {
+            function throwing_function() {
+                throw "nope";
+            }
+            try {
+                console.log((throwing_function(), "yes"));
+            } catch (ex) {
+                console.log(ex);
+            }
+            console.log("yes");
+            console.log("Yes");
+            console.log('' + anything);
+            console.log(anything + '');
+        }
+        foo();
+    }
+    expect_stdout: true
+}

test/compress/issue-1321.js

@@ -0,0 +1,57 @@
+issue_1321_no_debug: {
+    mangle_props = {
+        ignore_quoted: true
+    }
+    input: {
+        var x = {};
+        x.foo = 1;
+        x["a"] = 2 * x.foo;
+        console.log(x.foo, x["a"]);
+    }
+    expect: {
+        var x = {};
+        x.b = 1;
+        x["a"] = 2 * x.b;
+        console.log(x.b, x["a"]);
+    }
+    expect_stdout: true
+}
+
+issue_1321_debug: {
+    mangle_props = {
+        ignore_quoted: true,
+        debug: ""
+    }
+    input: {
+        var x = {};
+        x.foo = 1;
+        x["_$foo$_"] = 2 * x.foo;
+        console.log(x.foo, x["_$foo$_"]);
+    }
+    expect: {
+        var x = {};
+        x.a = 1;
+        x["_$foo$_"] = 2 * x.a;
+        console.log(x.a, x["_$foo$_"]);
+    }
+    expect_stdout: true
+}
+
+issue_1321_with_quoted: {
+    mangle_props = {
+        ignore_quoted: false
+    }
+    input: {
+        var x = {};
+        x.foo = 1;
+        x["a"] = 2 * x.foo;
+        console.log(x.foo, x["a"]);
+    }
+    expect: {
+        var x = {};
+        x.a = 1;
+        x["b"] = 2 * x.a;
+        console.log(x.a, x["b"]);
+    }
+    expect_stdout: true
+}

test/compress/issue-143.js

@@ -0,0 +1,48 @@
+/**
+ * There was an incorrect sort behaviour documented in issue #143:
+ * (x = f(…)) <= x → x >= (x = f(…))
+ *
+ * For example, let the equation be:
+ * (a = parseInt('100')) <= a
+ *
+ * If a was an integer and has the value of 99,
+ * (a = parseInt('100')) <= a → 100 <= 100 → true
+ *
+ * When transformed incorrectly:
+ * a >= (a = parseInt('100')) → 99 >= 100 → false
+ */
+
+tranformation_sort_order_equal: {
+    options = {
+        comparisons: true,
+    };
+
+    input: { (a = parseInt('100')) == a }
+    expect: { (a = parseInt('100')) == a }
+}
+
+tranformation_sort_order_unequal: {
+    options = {
+        comparisons: true,
+    };
+
+    input: { (a = parseInt('100')) != a }
+    expect: { (a = parseInt('100')) != a }
+}
+
+tranformation_sort_order_lesser_or_equal: {
+    options = {
+        comparisons: true,
+    };
+
+    input: { (a = parseInt('100')) <= a }
+    expect: { (a = parseInt('100')) <= a }
+}
+tranformation_sort_order_greater_or_equal: {
+    options = {
+        comparisons: true,
+    };
+
+    input: { (a = parseInt('100')) >= a }
+    expect: { (a = parseInt('100')) >= a }
+}

test/compress/issue-1431.js

@@ -0,0 +1,151 @@
+level_zero: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            function n(a) {
+                return a * a;
+            }
+            return function() {
+                return x;
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            function n(n) {
+                return n * n;
+            }
+            return function() {
+                return r;
+            };
+        }
+    }
+}
+
+level_one: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function n(a) {
+                    return a * a;
+                }
+                return x(n);
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            return function() {
+                function n(n) {
+                    return n * n;
+                }
+                return r(n);
+            };
+        }
+    }
+}
+
+level_two: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function r(a) {
+                    return a * a;
+                }
+                return function() {
+                    function n(a) {
+                        return a * a;
+                    }
+                    return x(n);
+                };
+            };
+        }
+    }
+    expect: {
+        function f(t) {
+            return function() {
+                function r(n) {
+                    return n * n;
+                }
+                return function() {
+                    function n(n) {
+                        return n * n;
+                    }
+                    return t(n);
+                };
+            };
+        }
+    }
+}
+
+level_three: {
+    options = {
+        keep_fnames: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(x) {
+            return function() {
+                function r(a) {
+                    return a * a;
+                }
+                return [
+                    function() {
+                        function t(a) {
+                            return a * a;
+                        }
+                        return t;
+                    },
+                    function() {
+                        function n(a) {
+                            return a * a;
+                        }
+                        return x(n);
+                    }
+                ];
+            };
+        }
+    }
+    expect: {
+        function f(t) {
+            return function() {
+                function r(n) {
+                    return n * n;
+                }
+                return [
+                    function() {
+                        function t(n) {
+                            return n * n;
+                        }
+                        return t;
+                    },
+                    function() {
+                        function n(n) {
+                            return n * n;
+                        }
+                        return t(n);
+                    }
+                ];
+            };
+        }
+    }
+}

test/compress/issue-1443.js

@@ -0,0 +1,61 @@
+// tests assume that variable `undefined` not redefined and has `void 0` as value
+
+unsafe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe: true
+    }
+    mangle = {}
+    input: {
+        function f(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }
+    }
+    expect: {
+        function f(n) {
+            return function() {
+                return a ? b : c ? d : n;
+            };
+        }
+    }
+}
+
+keep_fnames: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe: true
+    }
+    mangle = {
+        keep_fnames: true
+    }
+    input: {
+        function f(undefined) {
+            return function() {
+                function n(a) {
+                    return a * a;
+                }
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }
+    }
+    expect: {
+        function f(r) {
+            return function() {
+                function n(n) {
+                    return n * n;
+                }
+                return a ? b : c ? d : r;
+            };
+        }
+    }
+}

test/compress/issue-1446.js

@@ -0,0 +1,71 @@
+typeof_eq_undefined: {
+    options = {
+        comparisons: true
+    }
+    input: {
+        var a = typeof b != "undefined";
+        b = typeof a != "undefined";
+        var c = typeof d.e !== "undefined";
+        var f = "undefined" === typeof g;
+        g = "undefined" === typeof f;
+        var h = "undefined" == typeof i.j;
+    }
+    expect: {
+        var a = "undefined" != typeof b;
+        b = void 0 !== a;
+        var c = void 0 !== d.e;
+        var f = "undefined" == typeof g;
+        g = void 0 === f;
+        var h = void 0 === i.j;
+    }
+}
+
+typeof_eq_undefined_ie8: {
+    options = {
+        comparisons: true,
+        screw_ie8: false
+    }
+    input: {
+        var a = typeof b != "undefined";
+        b = typeof a != "undefined";
+        var c = typeof d.e !== "undefined";
+        var f = "undefined" === typeof g;
+        g = "undefined" === typeof f;
+        var h = "undefined" == typeof i.j;
+    }
+    expect: {
+        var a = "undefined" != typeof b;
+        b = void 0 !== a;
+        var c = "undefined" != typeof d.e;
+        var f = "undefined" == typeof g;
+        g = void 0 === f;
+        var h = "undefined" == typeof i.j;
+    }
+}
+
+undefined_redefined: {
+    options = {
+        comparisons: true
+    }
+    input: {
+        function f(undefined) {
+            var n = 1;
+            return typeof n == "undefined";
+        }
+    }
+    expect_exact: "function f(undefined){var n=1;return void 0===n}"
+}
+
+undefined_redefined_mangle: {
+    options = {
+        comparisons: true
+    }
+    mangle = {}
+    input: {
+        function f(undefined) {
+            var n = 1;
+            return typeof n == "undefined";
+        }
+    }
+    expect_exact: "function f(n){var r=1;return void 0===r}"
+}

test/compress/issue-1447.js

@@ -0,0 +1,46 @@
+else_with_empty_block: {
+    options = {}
+    input: {
+        if (x)
+            yes();
+        else {
+        }
+    }
+    expect_exact: "if(x)yes();"
+}
+
+else_with_empty_statement: {
+    options = {}
+    input: {
+        if (x)
+            yes();
+        else
+            ;
+    }
+    expect_exact: "if(x)yes();"
+}
+
+conditional_false_stray_else_in_loop: {
+    options = {
+        evaluate     : true,
+        comparisons  : true,
+        booleans     : true,
+        unused       : true,
+        loops        : true,
+        side_effects : true,
+        dead_code    : true,
+        hoist_vars   : true,
+        join_vars    : true,
+        if_return    : true,
+        cascade      : true,
+        conditionals : false,
+    }
+    input: {
+        for (var i = 1; i <= 4; ++i) {
+            if (i <= 2) continue;
+            console.log(i);
+        }
+    }
+    expect_exact: "for(var i=1;i<=4;++i)if(!(i<=2))console.log(i);"
+    expect_stdout: true
+}

test/compress/issue-1466.js

@@ -0,0 +1,291 @@
+same_variable_in_multiple_for_loop: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        for (let i = 0; i < 3; i++) {
+            let a = 100;
+            console.log(i, a);
+            for (let i = 0; i < 2; i++) {
+                console.log(i, a);
+                let c = 2;
+                console.log(c);
+            }
+        }
+    }
+    expect: {
+        for (let o = 0; o < 3; o++) {
+            let l = 100;
+            console.log(o, l);
+            for (let o = 0; o < 2; o++) {
+                console.log(o, l);
+                let c = 2;
+                console.log(c);
+            }
+        }
+    }
+    expect_stdout: true
+}
+
+same_variable_in_multiple_forOf: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp of dd) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o of test) {
+            console.log(o);
+            let e;
+            e = [ "e", "f", "g" ];
+            for (let o of e)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+}
+
+same_variable_in_multiple_forIn: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let tmp in test) {
+                console.log(tmp);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o in test) {
+            console.log(o);
+            let e;
+            e = [ "e", "f", "g" ];
+            for (let o in test)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+}
+
+different_variable_in_multiple_for_loop: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        for (let i = 0; i < 3; i++) {
+            let a = 100;
+            console.log(i, a);
+            for (let j = 0; j < 2; j++) {
+                console.log(j, a);
+                let c = 2;
+                console.log(c);
+            }
+        }
+    }
+    expect: {
+        for (let o = 0; o < 3; o++) {
+            let l = 100;
+            console.log(o, l);
+            for (let o = 0; o < 2; o++) {
+                console.log(o, l);
+                let c = 2;
+                console.log(c);
+            }
+        }
+    }
+    expect_stdout: true
+}
+
+different_variable_in_multiple_forOf: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: true,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp of test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let t of dd) {
+                console.log(t);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o of test) {
+            console.log(o);
+            let e;
+            e = [ "e", "f", "g" ];
+            for (let o of e)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+}
+
+different_variable_in_multiple_forIn: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        var test = [ "a", "b", "c" ];
+        for (let tmp in test) {
+            console.log(tmp);
+            let dd;
+            dd = [ "e", "f", "g" ];
+            for (let t in test) {
+                console.log(t);
+            }
+        }
+    }
+    expect: {
+        var test = [ "a", "b", "c" ];
+        for (let o in test) {
+            console.log(o);
+            let e;
+            e = [ "e", "f", "g" ];
+            for (let o in test)
+                console.log(o);
+        }
+    }
+    expect_stdout: true
+}
+
+more_variable_in_multiple_for: {
+    options = {
+        hoist_funs: true,
+        dead_code: true,
+        conditionals: true,
+        comparisons: true,
+        evaluate: true,
+        booleans: true,
+        loops: true,
+        unused: false,
+        keep_fargs: true,
+        if_return: true,
+        join_vars: true,
+        cascade: true,
+        side_effects: true,
+        collapse_vars: true,
+    }
+    mangle = {}
+    input: {
+        for (let a = 9, i = 0; i < 20; i += a) {
+            let b = a++ + i;
+            console.log(a, b, i);
+            for (let k = b, m = b*b, i = 0; i < 10; i++) {
+                console.log(a, b, m, k, i);
+            }
+        }
+    }
+    expect: {
+        for (let o = 9, l = 0; l < 20; l += o) {
+            let c = o++ + l;
+            console.log(o, c, l);
+            for (let l = c, e = c * c, f = 0; f < 10; f++)
+                console.log(o, c, e, l, f);
+        }
+    }
+    expect_stdout: true
+}

test/compress/issue-1569.js

@@ -0,0 +1,19 @@
+inner_reference: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        !function f(a) {
+            return a && f(a - 1) + a;
+        }(42);
+        !function g(a) {
+            return a;
+        }(42);
+    }
+    expect: {
+        !function f(a) {
+            return a && f(a - 1) + a;
+        }(42);
+        !void 0;
+    }
+}

test/compress/issue-1588.js

@@ -0,0 +1,99 @@
+screw_ie8: {
+    options = {
+        screw_ie8: true,
+    }
+    mangle = {
+        screw_ie8: true,
+    }
+    input: {
+        try { throw "foo"; } catch (x) { console.log(x); }
+    }
+    expect_exact: 'try{throw"foo"}catch(o){console.log(o)}'
+    expect_stdout: [
+        "foo"
+    ]
+}
+
+support_ie8: {
+    options = {
+        screw_ie8: false,
+    }
+    mangle = {
+        screw_ie8: false,
+    }
+    input: {
+        try { throw "foo"; } catch (x) { console.log(x); }
+    }
+    expect_exact: 'try{throw"foo"}catch(x){console.log(x)}'
+    expect_stdout: "foo"
+}
+
+safe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe: false,
+    }
+    mangle = {}
+    input: {
+        var a, c;
+        console.log(function(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }(1)());
+    }
+    expect: {
+        var a, c;
+        console.log(function(n) {
+            return function() {
+                return a ? b : c ? d : void 0;
+            };
+        }(1)());
+    }
+    expect_stdout: true
+}
+
+unsafe_undefined: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        unsafe: true,
+    }
+    mangle = {}
+    input: {
+        var a, c;
+        console.log(function(undefined) {
+            return function() {
+                if (a)
+                    return b;
+                if (c)
+                    return d;
+            };
+        }()());
+    }
+    expect: {
+        var a, c;
+        console.log(function(n) {
+            return function() {
+                return a ? b : c ? d : n;
+            };
+        }()());
+    }
+    expect_stdout: true
+}
+
+runtime_error: {
+    input: {
+        const a = 1;
+        console.log(a++);
+    }
+    expect: {
+        const a = 1;
+        console.log(a++);
+    }
+    expect_stdout: true
+}

test/compress/issue-1609.js

@@ -0,0 +1,56 @@
+chained_evaluation_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = 1;
+            (function() {
+                var b = a, c;
+                c = f(b);
+                c.bar = b;
+            })();
+        })();
+    }
+    expect: {
+        (function() {
+            (function() {
+                var c;
+                c = f(1);
+                c.bar = 1;
+            })();
+        })();
+    }
+}
+
+chained_evaluation_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = "long piece of string";
+            (function() {
+                var b = a, c;
+                c = f(b);
+                c.bar = b;
+            })();
+        })();
+    }
+    expect: {
+        (function() {
+            var a = "long piece of string";
+            (function() {
+                var c;
+                c = f(a);
+                c.bar = a;
+            })();
+        })();
+    }
+}

test/compress/issue-1639.js

@@ -0,0 +1,88 @@
+
+issue_1639_1: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        evaluate: true,
+        join_vars: true,
+        loops: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+
+        var L1 = 5;
+        while (--L1 > 0) {
+            if ((--b), false) {
+                if (b) {
+                    var ignore = 0;
+                }
+            }
+        }
+
+        console.log(a, b);
+    }
+    expect: {
+        for (var a = 100, b = 10, L1 = 5; --L1 > 0;)
+            if (--b, !1) var ignore = 0;
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+issue_1639_2: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        evaluate: true,
+        join_vars: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+
+        function f19() {
+            if (++a, false)
+                if (a)
+                    if (++a);
+        }
+        f19();
+
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        function f19() {
+            ++a, 1;
+        }
+        f19(),
+        console.log(a, b);
+    }
+    expect_stdout: true
+}
+
+issue_1639_3: {
+    options = {
+        booleans: true,
+        cascade: true,
+        conditionals: true,
+        evaluate: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        a++ && false && a ? 0 : 0;
+        console.log(a, b);
+    }
+    expect: {
+        var a = 100, b = 10;
+        a++,
+        console.log(a, b);
+    }
+    expect_stdout: true
+}

test/compress/issue-1656.js

@@ -0,0 +1,45 @@
+f7: {
+    options = {
+        booleans: true,
+        cascade: true,
+        collapse_vars: true,
+        comparisons: true,
+        conditionals: true,
+        dead_code: true,
+        drop_debugger: true,
+        evaluate: true,
+        hoist_funs: true,
+        if_return: true,
+        join_vars: true,
+        loops: true,
+        negate_iife: true,
+        passes: 3,
+        properties: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        var a = 100, b = 10;
+        function f22464() {
+            var brake146670 = 5;
+            while (((b = a) ? !a : ~a ? null : b += a) && --brake146670 > 0) {
+            }
+        }
+        f22464();
+        console.log(a, b);
+    }
+    expect_exact: [
+        "var a = 100, b = 10;",
+        "",
+        "!function() {",
+        "    for (;b = a, !1; ) ;",
+        "}(), console.log(a, b);",
+    ]
+    expect_stdout: true
+}

test/compress/issue-1673.js

@@ -0,0 +1,159 @@
+side_effects_catch: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                try {
+                    throw 0;
+                } catch (e) {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                    throw 0;
+                } catch (e) {
+                    console.log("PASS");
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_else: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            function g() {
+                if (x);
+                else console.log("PASS");
+            }
+            g();
+        }
+        f(0);
+    }
+    expect: {
+        function f(x) {
+            (function() {
+                if (x);
+                else console.log("PASS");
+            })();
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_finally: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                try {
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_label: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(x) {
+            function g() {
+                L: {
+                    console.log("PASS");
+                    break L;
+                }
+            }
+            g();
+        }
+        f(0);
+    }
+    expect: {
+        function f(x) {
+            (function() {
+                L: {
+                    console.log("PASS");
+                    break L;
+                }
+            })();
+        }
+        f(0);
+    }
+    expect_stdout: "PASS"
+}
+
+side_effects_switch: {
+    options = {
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                switch (0) {
+                  default:
+                  case console.log("PASS"):
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                switch (0) {
+                  default:
+                  case console.log("PASS"):
+                }
+            })();
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}

test/compress/issue-1704.js

@@ -0,0 +1,347 @@
+mangle_catch: {
+    options = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(o){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8: {
+    options = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(args){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var: {
+    options = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(o){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8: {
+    options = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="FAIL";try{throw 1}catch(args){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_toplevel: {
+    options = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8_toplevel: {
+    options = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_toplevel: {
+    options = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8_toplevel: {
+    options = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw 1;
+        } catch (args) {
+            var a = "PASS";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1: {
+    options = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="PASS";try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_ie8: {
+    options = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var a="PASS";try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_toplevel: {
+    options = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="PASS";try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_1_ie8_toplevel: {
+    options = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'var o="PASS";try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_2: {
+    options = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: false,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_ie8: {
+    options = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: false,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(a){var a="FAIL2"}console.log(a);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_toplevel: {
+    options = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: true,
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "undefined"
+}
+
+mangle_catch_redef_2_ie8_toplevel: {
+    options = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        screw_ie8: false,
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw "FAIL1";
+        } catch (a) {
+            var a = "FAIL2";
+        }
+        console.log(a);
+    }
+    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
+    expect_stdout: "undefined"
+}

test/compress/issue-203.js

@@ -0,0 +1,34 @@
+
+compress_new_function: {
+    options = {
+        unsafe: true
+    }
+    input: {
+        new Function("aa, bb", 'return aa;');
+    }
+    expect: {
+        Function("a", "b", "return a");
+    }
+}
+
+compress_new_function_with_destruct: {
+    options = {
+        unsafe: true,
+        ecma: 6
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        new Function("aa, [bb]", 'return aa;');
+        new Function("aa, {bb}", 'return aa;');
+        new Function("[[aa]], [{bb}]", 'return aa;');
+    }
+    expect: {
+        Function("a", "[b]", "return a");
+        Function("a", "{bb}", "return a");
+        Function("[[a]]", "[{bb}]", 'return a');
+    }
+}
+
+

test/compress/issue-208.js

@@ -0,0 +1,70 @@
+do_not_update_lhs: {
+    options = {
+        global_defs: { DEBUG: 0 }
+    }
+    input: {
+        DEBUG++;
+        DEBUG += 1;
+        DEBUG = 1;
+    }
+    expect: {
+        DEBUG++;
+        DEBUG += 1;
+        DEBUG = 1;
+    }
+}
+
+do_update_rhs: {
+    options = {
+        global_defs: { DEBUG: 0 }
+    }
+    input: {
+        MY_DEBUG = DEBUG;
+        MY_DEBUG += DEBUG;
+    }
+    expect: {
+        MY_DEBUG = 0;
+        MY_DEBUG += 0;
+    }
+}
+
+mixed: {
+    options = {
+        evaluate: true,
+        global_defs: {
+            DEBUG: 0,
+            ENV: 1,
+            FOO: 2,
+        }
+    }
+    input: {
+        const ENV = 3;
+        var FOO = 4;
+        f(ENV * 10);
+        --FOO;
+        DEBUG = 1;
+        DEBUG++;
+        DEBUG += 1;
+        f(DEBUG);
+        x = DEBUG;
+    }
+    expect: {
+        const ENV = 3;
+        var FOO = 4;
+        f(10);
+        --FOO;
+        DEBUG = 1;
+        DEBUG++;
+        DEBUG += 1;
+        f(0);
+        x = 0;
+    }
+    expect_warnings: [
+        'WARN: global_defs ENV redefined [test/compress/issue-208.js:41,14]',
+        'WARN: global_defs FOO redefined [test/compress/issue-208.js:42,12]',
+        'WARN: global_defs FOO redefined [test/compress/issue-208.js:44,10]',
+        'WARN: global_defs DEBUG redefined [test/compress/issue-208.js:45,8]',
+        'WARN: global_defs DEBUG redefined [test/compress/issue-208.js:46,8]',
+        'WARN: global_defs DEBUG redefined [test/compress/issue-208.js:47,8]',
+    ]
+}

test/compress/issue-267.js

@@ -0,0 +1,11 @@
+issue_267: {
+    options = { comparisons: true };
+    input: {
+        x = a % b / b * c * 2;
+        x = a % b * 2
+    }
+    expect: {
+        x = a % b / b * c * 2;
+        x = a % b * 2;
+    }
+}

test/compress/issue-269.js

@@ -0,0 +1,66 @@
+issue_269_1: {
+	options = {unsafe: true};
+	input: {
+		f(
+			String(x),
+			Number(x),
+			Boolean(x),
+
+			String(),
+			Number(),
+			Boolean()
+		);
+	}
+	expect: {
+		f(
+			x + '', +x, !!x,
+			'', 0, false
+		);
+	}
+}
+
+issue_269_dangers: {
+	options = {unsafe: true};
+	input: {
+		f(
+			String(x, x),
+			Number(x, x),
+			Boolean(x, x)
+		);
+	}
+	expect: {
+		f(String(x, x), Number(x, x), Boolean(x, x));
+	}
+}
+
+issue_269_in_scope: {
+	options = {unsafe: true};
+	input: {
+		var String, Number, Boolean;
+		f(
+			String(x),
+			Number(x, x),
+			Boolean(x)
+		);
+	}
+	expect: {
+		var String, Number, Boolean;
+		f(String(x), Number(x, x), Boolean(x));
+	}
+}
+
+strings_concat: {
+	options = {unsafe: true};
+	input: {
+		f(
+			String(x + 'str'),
+			String('str' + x)
+		);
+	}
+	expect: {
+		f(
+			x + 'str',
+			'str' + x
+		);
+	}
+}

test/compress/issue-368.js

@@ -0,0 +1,55 @@
+collapse: {
+    options = {
+        cascade: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f1() {
+            var a;
+            a = typeof b === 'function' ? b() : b;
+            return a !== undefined && c();
+        }
+        function f2(b) {
+            var a;
+            b = c();
+            a = typeof b === 'function' ? b() : b;
+            return 'stirng' == typeof a && d();
+        }
+        function f3(c) {
+            var a;
+            a = b(a / 2);
+            if (a < 0) {
+                a++;
+                ++c;
+                return c / 2;
+            }
+        }
+        function f4(c) {
+            var a;
+            a = b(a / 2);
+            if (a < 0) {
+                a++;
+                c++;
+                return c / 2;
+            }
+        }
+    }
+    expect: {
+        function f1() {
+            return void 0 !== ('function' === typeof b ? b() : b) && c();
+        }
+        function f2(b) {
+            return b = c(), 'stirng' == typeof ('function' === typeof b ? b() : b) && d();
+        }
+        function f3(c) {
+            var a;
+            if ((a = b(a / 2)) < 0) return a++, ++c / 2;
+        }
+        function f4(c) {
+            var a;
+            if ((a = b(a / 2)) < 0) return a++, ++c / 2;
+        }
+    }
+}

test/compress/issue-59.js

@@ -0,0 +1,30 @@
+keep_continue: {
+    options = {
+        dead_code: true,
+        evaluate: true
+    };
+    input: {
+        while (a) {
+            if (b) {
+                switch (true) {
+                  case c():
+                    d();
+                }
+                continue;
+            }
+            f();
+        }
+    }
+    expect: {
+        while (a) {
+            if (b) {
+                switch (true) {
+                  case c():
+                    d();
+                }
+                continue;
+            }
+            f();
+        }
+    }
+}

test/compress/issue-597.js

@@ -0,0 +1,25 @@
+NaN_and_Infinity_must_have_parens: {
+    options = {};
+    input: {
+        Infinity.toString();
+        NaN.toString();
+    }
+    expect: {
+        (1/0).toString();
+        NaN.toString();         // transformation to 0/0 dropped
+    }
+}
+
+NaN_and_Infinity_should_not_be_replaced_when_they_are_redefined: {
+    options = {};
+    input: {
+        var Infinity, NaN;
+        Infinity.toString();
+        NaN.toString();
+    }
+    expect: {
+        var Infinity, NaN;
+        Infinity.toString();
+        NaN.toString();
+    }
+}

test/compress/issue-611.js

@@ -0,0 +1,21 @@
+issue_611: {
+  options = {
+    sequences: true,
+    side_effects: true
+  };
+  input: {
+    define(function() {
+      function fn() {}
+      if (fn()) {
+        fn();
+        return void 0;
+      }
+    });
+  }
+  expect: {
+    define(function() {
+      function fn(){}
+      if (fn()) return void fn();
+    });
+  }
+}

test/compress/issue-637.js

@@ -0,0 +1,22 @@
+wrongly_optimized: {
+    options = {
+        conditionals: true,
+        booleans: true,
+        evaluate: true
+    };
+    input: {
+        function func() {
+            foo();
+        }
+        if (func() || true) {
+            bar();
+        }
+    }
+    expect: {
+        function func() {
+            foo();
+        }
+        // TODO: optimize to `func(), bar()`
+        (func(), 0) || bar();
+    }
+}

test/compress/issue-640.js

@@ -0,0 +1,320 @@
+cond_5: {
+    options = {
+        conditionals: true,
+        expression: true,
+    }
+    input: {
+        if (some_condition()) {
+            if (some_other_condition()) {
+                do_something();
+            } else {
+                alternate();
+            }
+        } else {
+            alternate();
+        }
+
+        if (some_condition()) {
+            if (some_other_condition()) {
+                do_something();
+            }
+        }
+    }
+    expect: {
+        some_condition() && some_other_condition() ? do_something() : alternate();
+        if (some_condition() && some_other_condition()) do_something();
+    }
+}
+
+dead_code_const_annotation_regex: {
+    options = {
+        booleans     : true,
+        conditionals : true,
+        dead_code    : true,
+        evaluate     : true,
+        expression   : true,
+        loops        : true,
+    }
+    input: {
+        var unused;
+        // @constraint this shouldn't be a constant
+        var CONST_FOO_ANN = false;
+        if (CONST_FOO_ANN) {
+            console.log("reachable");
+        }
+    }
+    expect: {
+        var unused;
+        var CONST_FOO_ANN = !1;
+        if (CONST_FOO_ANN) console.log('reachable');
+    }
+    expect_stdout: true
+}
+
+drop_console_2: {
+    options = {
+        drop_console: true,
+        expression: true,
+    }
+    input: {
+        console.log('foo');
+        console.log.apply(console, arguments);
+    }
+    expect: {
+        // with regular compression these will be stripped out as well
+        void 0;
+        void 0;
+    }
+}
+
+drop_value: {
+    options = {
+        expression: true,
+        side_effects: true,
+    }
+    input: {
+        (1, [2, foo()], 3, {a:1, b:bar()});
+    }
+    expect: {
+        foo(), {a:1, b:bar()};
+    }
+}
+
+wrongly_optimized: {
+    options = {
+        conditionals: true,
+        booleans: true,
+        evaluate: true,
+        expression: true,
+    }
+    input: {
+        function func() {
+            foo();
+        }
+        if (func() || true) {
+            bar();
+        }
+    }
+    expect: {
+        function func() {
+            foo();
+        }
+        // TODO: optimize to `func(), bar()`
+        if (func(), !0) bar();
+    }
+}
+
+negate_iife_1: {
+    options = {
+        expression: true,
+        negate_iife: true,
+    }
+    input: {
+        (function(){ stuff() })();
+    }
+    expect: {
+        (function(){ stuff() })();
+    }
+}
+
+negate_iife_3: {
+    options = {
+        conditionals: true,
+        expression: true,
+        negate_iife: true,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+}
+
+negate_iife_3_off: {
+    options = {
+        conditionals: true,
+        expression: true,
+        negate_iife: false,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+}
+
+negate_iife_4: {
+    options = {
+        conditionals: true,
+        expression: true,
+        negate_iife: true,
+        sequences: true,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        (function(){ return t })() ? console.log(true) : console.log(false), function(){
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_5: {
+    options = {
+        conditionals: true,
+        expression: true,
+        negate_iife: true,
+        sequences: true,
+    }
+    input: {
+        if ((function(){ return t })()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        (function(){ return t })() ? foo(true) : bar(false), function(){
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_5_off: {
+    options = {
+        conditionals: true,
+        expression: true,
+        negate_iife: false,
+        sequences: true,
+    };
+    input: {
+        if ((function(){ return t })()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        (function(){ return t })() ? foo(true) : bar(false), function(){
+            console.log("something");
+        }();
+    }
+}
+
+issue_1254_negate_iife_true: {
+    options = {
+        expression: true,
+        negate_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()();
+    }
+    expect_exact: '(function(){return function(){console.log("test")}})()();'
+    expect_stdout: true
+}
+
+issue_1254_negate_iife_nested: {
+    options = {
+        expression: true,
+        negate_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()()()()();
+    }
+    expect_exact: '(function(){return function(){console.log("test")}})()()()()();'
+    expect_stdout: true
+}
+
+conditional: {
+    options = {
+        expression: true,
+        pure_funcs: [ "pure" ],
+        side_effects: true,
+    }
+    input: {
+        pure(1 | a() ? 2 & b() : 7 ^ c());
+        pure(1 | a() ? 2 & b() : 5);
+        pure(1 | a() ? 4 : 7 ^ c());
+        pure(1 | a() ? 4 : 5);
+        pure(3 ? 2 & b() : 7 ^ c());
+        pure(3 ? 2 & b() : 5);
+        pure(3 ? 4 : 7 ^ c());
+        pure(3 ? 4 : 5);
+    }
+    expect: {
+        1 | a() ? b() : c();
+        1 | a() && b();
+        1 | a() || c();
+        a();
+        3 ? b() : c();
+        3 && b();
+        3 || c();
+        pure(3 ? 4 : 5);
+    }
+}
+
+limit_1: {
+    options = {
+        expression: true,
+        sequences: 3,
+    }
+    input: {
+        a;
+        b;
+        c;
+        d;
+        e;
+        f;
+        g;
+        h;
+        i;
+        j;
+        k;
+    }
+    expect: {
+        // Turned into a single return statement
+        // so it can no longer be split into lines
+        a,b,c,d,e,f,g,h,i,j,k;
+    }
+}
+
+iife: {
+    options = {
+        expression: true,
+        sequences: true,
+    }
+    input: {
+        x = 42;
+        (function a() {})();
+        !function b() {}();
+        ~function c() {}();
+        +function d() {}();
+        -function e() {}();
+        void function f() {}();
+        typeof function g() {}();
+    }
+    expect: {
+        x = 42, function a() {}(), function b() {}(), function c() {}(),
+        function d() {}(), function e() {}(), function f() {}(), typeof function g() {}();
+    }
+}

test/compress/issue-747.js

@@ -0,0 +1,37 @@
+dont_reuse_prop: {
+    mangle_props = {
+        regex: /asd/
+    };
+
+    input: {
+        var obj = {};
+        obj.a = 123;
+        obj.asd = 256;
+        console.log(obj.a);
+    }
+    expect: {
+        var obj = {};
+        obj.a = 123;
+        obj.b = 256;
+        console.log(obj.a);
+    }
+}
+
+unmangleable_props_should_always_be_reserved: {
+    mangle_props = {
+        regex: /asd/
+    };
+
+    input: {
+        var obj = {};
+        obj.asd = 256;
+        obj.a = 123;
+        console.log(obj.a);
+    }
+    expect: {
+        var obj = {};
+        obj.b = 256;
+        obj.a = 123;
+        console.log(obj.a);
+    }
+}

test/compress/issue-751.js

@@ -0,0 +1,29 @@
+negate_booleans_1: {
+    options = {
+        comparisons: true
+    };
+    input: {
+        var a = !a || !b || !c || !d || !e || !f;
+    }
+    expect: {
+        var a = !(a && b && c && d && e && f);
+    }
+}
+
+negate_booleans_2: {
+    options = {
+        comparisons: true
+    };
+    input: {
+        var match = !x &&       // should not touch this one
+            (!z || c) &&
+            (!k || d) &&
+            the_stuff();
+    }
+    expect: {
+        var match = !x &&
+            (!z || c) &&
+            (!k || d) &&
+            the_stuff();
+    }
+}

test/compress/issue-782.js

@@ -0,0 +1,27 @@
+remove_redundant_sequence_items: {
+    options = { side_effects: true };
+    input: {
+        (0, 1, eval)();
+        (0, 1, logThis)();
+        (0, 1, _decorators.logThis)();
+    }
+    expect: {
+        (0, eval)();
+        logThis();
+        (0, _decorators.logThis)();
+    }
+}
+
+dont_remove_this_binding_sequence: {
+    options = { side_effects: true };
+    input: {
+        (0, eval)();
+        (0, logThis)();
+        (0, _decorators.logThis)();
+    }
+    expect: {
+        (0, eval)();
+        logThis();
+        (0, _decorators.logThis)();
+    }
+}

test/compress/issue-892.js

@@ -0,0 +1,33 @@
+dont_mangle_arguments: {
+    mangle = {
+    };
+    options = {
+        sequences     : true,
+        properties    : true,
+        dead_code     : true,
+        drop_debugger : true,
+        conditionals  : true,
+        comparisons   : true,
+        evaluate      : true,
+        booleans      : true,
+        loops         : true,
+        unused        : true,
+        hoist_funs    : true,
+        keep_fargs    : true,
+        keep_fnames   : false,
+        hoist_vars    : true,
+        if_return     : true,
+        join_vars     : true,
+        cascade       : true,
+        side_effects  : true,
+        negate_iife   : false
+    };
+    input: {
+        (function(){
+            var arguments = arguments, not_arguments = 9;
+            console.log(not_arguments, arguments);
+        })(5,6,7);
+    }
+    expect_exact: "(function(){var arguments=arguments,o=9;console.log(o,arguments)})(5,6,7);"
+    expect_stdout: true
+}

test/compress/issue-913.js

@@ -0,0 +1,20 @@
+keep_var_for_in: {
+    options = {
+        hoist_vars: true,
+        unused: true
+    };
+    input: {
+        (function(obj){
+            var foo = 5;
+            for (var i in obj)
+                return foo;
+        })();
+    }
+    expect: {
+        (function(obj){
+            var i, foo = 5;
+            for (i in obj)
+                return foo;
+        })();
+    }
+}

test/compress/issue-926.js

@@ -0,0 +1,9 @@
+template_strings: {
+    input: {
+        foo(
+            `<span>${contents}</span>`,
+            `<a href="${url}">${text}</a>`
+        );
+    }
+    expect_exact: "foo(`<span>${contents}</span>`,`<a href=\"${url}\">${text}</a>`);"
+}

test/compress/issue-973.js

@@ -0,0 +1,97 @@
+this_binding_conditionals: {
+    options = {
+        conditionals: true,
+        evaluate    : true
+    };
+    input: {
+        (1 && a)();
+        (0 || a)();
+        (0 || 1 && a)();
+        (1 ? a : 0)();
+
+        (1 && a.b)();
+        (0 || a.b)();
+        (0 || 1 && a.b)();
+        (1 ? a.b : 0)();
+
+        (1 && a[b])();
+        (0 || a[b])();
+        (0 || 1 && a[b])();
+        (1 ? a[b] : 0)();
+
+        (1 && eval)();
+        (0 || eval)();
+        (0 || 1 && eval)();
+        (1 ? eval : 0)();
+    }
+    expect: {
+        a();
+        a();
+        a();
+        a();
+
+        (0, a.b)();
+        (0, a.b)();
+        (0, a.b)();
+        (0, a.b)();
+
+        (0, a[b])();
+        (0, a[b])();
+        (0, a[b])();
+        (0, a[b])();
+
+        (0, eval)();
+        (0, eval)();
+        (0, eval)();
+        (0, eval)();
+    }
+}
+
+this_binding_collapse_vars: {
+    options = {
+        collapse_vars: true,
+        toplevel: true,
+    };
+    input: {
+        var c = a; c();
+        var d = a.b; d();
+        var e = eval; e();
+    }
+    expect: {
+        a();
+        (0, a.b)();
+        (0, eval)();
+    }
+}
+
+this_binding_side_effects: {
+    options = {
+        side_effects : true
+    };
+    input: {
+        (function (foo) {
+            (0, foo)();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
+        (function (foo) {
+            var eval = console;
+            (0, foo)();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
+    }
+    expect: {
+        (function (foo) {
+            foo();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
+        (function (foo) {
+            var eval = console;
+            foo();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
+    }
+}

test/compress/issue-976.js

@@ -0,0 +1,89 @@
+eval_collapse_vars: {
+    options = {
+        collapse_vars:true, sequences:false, properties:true, dead_code:true, conditionals:true,
+        comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
+        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+    };
+    input: {
+        function f1() {
+            var e = 7;
+            var s = "abcdef";
+            var i = 2;
+            var eval = console.log.bind(console);
+            var x = s.charAt(i++);
+            var y = s.charAt(i++);
+            var z = s.charAt(i++);
+            eval(x, y, z, e);
+        }
+        function p1() { var a = foo(), b = bar(), eval = baz(); return a + b + eval; }
+        function p2() { var a = foo(), b = bar(), eval = baz; return a + b + eval(); }
+        (function f2(eval) {
+            var a = 2;
+            console.log(a - 5);
+            eval("console.log(a);");
+        })(eval);
+    }
+    expect: {
+        function f1() {
+            var e = 7,
+                s = "abcdef",
+                i = 2,
+                eval = console.log.bind(console),
+                x = s.charAt(i++),
+                y = s.charAt(i++),
+                z = s.charAt(i++);
+            eval(x, y, z, e);
+        }
+        function p1() { return foo() + bar() + baz(); }
+        function p2() { var a = foo(), b = bar(), eval = baz; return a + b + eval(); }
+        (function f2(eval) {
+            var a = 2;
+            console.log(a - 5);
+            eval("console.log(a);");
+        })(eval);
+    }
+    expect_stdout: true
+}
+
+eval_unused: {
+    options = { unused: true, keep_fargs: false };
+    input: {
+        function f1(a, eval, c, d, e) {
+            return a('c') + eval;
+        }
+        function f2(a, b, c, d, e) {
+            return a + eval('c');
+        }
+        function f3(a, eval, c, d, e) {
+            return a + eval('c');
+        }
+    }
+    expect: {
+        function f1(a, eval) {
+            return a('c') + eval;
+        }
+        function f2(a, b, c, d, e) {
+            return a + eval('c');
+        }
+        function f3(a, eval, c, d, e) {
+            return a + eval('c');
+        }
+    }
+}
+
+eval_mangle: {
+    mangle = {
+    };
+    input: {
+        function f1(a, eval, c, d, e) {
+            return a('c') + eval;
+        }
+        function f2(a, b, c, d, e) {
+            return a + eval('c');
+        }
+        function f3(a, eval, c, d, e) {
+            return a + eval('c');
+        }
+    }
+    expect_exact: 'function f1(n,c,e,a,f){return n("c")+c}function f2(a,b,c,d,e){return a+eval("c")}function f3(a,eval,c,d,e){return a+eval("c")}'
+}

test/compress/issue-979.js

@@ -0,0 +1,89 @@
+issue979_reported: {
+    options = {
+        sequences:true, properties:true, dead_code:true, conditionals:true,
+        comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
+        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+    }
+    input: {
+        function f1() {
+            if (a == 1 || b == 2) {
+                foo();
+            }
+        }
+        function f2() {
+            if (!(a == 1 || b == 2)) {
+            }
+            else {
+                foo();
+            }
+        }
+    }
+    expect: {
+        function f1() {
+            1!=a&&2!=b||foo();
+        }
+        function f2() {
+            1!=a&&2!=b||foo();
+        }
+    }
+}
+
+issue979_test_negated_is_best: {
+    options = {
+        sequences:true, properties:true, dead_code:true, conditionals:true,
+        comparisons:true, evaluate:true, booleans:true, loops:true, unused:true, hoist_funs:true,
+        keep_fargs:true, if_return:true, join_vars:true, cascade:true, side_effects:true
+    }
+    input: {
+        function f3() {
+            if (a == 1 | b == 2) {
+                foo();
+            }
+        }
+        function f4() {
+            if (!(a == 1 | b == 2)) {
+            }
+            else {
+                foo();
+            }
+        }
+        function f5() {
+            if (a == 1 && b == 2) {
+                foo();
+            }
+        }
+        function f6() {
+            if (!(a == 1 && b == 2)) {
+            }
+            else {
+                foo();
+            }
+        }
+        function f7() {
+            if (a == 1 || b == 2) {
+                foo();
+            }
+            else {
+                return bar();
+            }
+        }
+    }
+    expect: {
+        function f3() {
+            1==a|2==b&&foo();
+        }
+        function f4() {
+            1==a|2==b&&foo();
+        }
+        function f5() {
+            1==a&&2==b&&foo();
+        }
+        function f6() {
+            1!=a||2!=b||foo();
+        }
+        function f7() {
+            if(1!=a&&2!=b)return bar();foo()
+        }
+    }
+}
+

test/compress/join-vars.js

@@ -0,0 +1,40 @@
+only_vars: {
+    options = { join_vars: true };
+    input: {
+        let netmaskBinary = '';
+        for (let i = 0; i < netmaskBits; ++i) {
+            netmaskBinary += '1';
+        }
+    }
+    expect: {
+        let netmaskBinary = '';
+        for (let i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
+    }
+}
+
+issue_1079_with_vars: {
+    options = { join_vars: true };
+    input: {
+        var netmaskBinary = '';
+        for (var i = 0; i < netmaskBits; ++i) {
+            netmaskBinary += '1';
+        }
+    }
+    expect: {
+        for (var netmaskBinary = '', i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
+    }
+}
+
+issue_1079_with_mixed: {
+    options = { join_vars: true };
+    input: {
+        var netmaskBinary = '';
+        for (let i = 0; i < netmaskBits; ++i) {
+            netmaskBinary += '1';
+        }
+    }
+    expect: {
+        var netmaskBinary = ''
+        for (let i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
+    }
+}

test/compress/labels.js

@@ -9,6 +9,7 @@ labels_1: {
     expect: {
         foo || console.log("bar");
     }
+    expect_stdout: true
 }
 
 labels_2: {
@@ -40,6 +41,7 @@ labels_3: {
         for (var i = 0; i < 5; ++i)
             i < 3 || console.log(i);
     }
+    expect_stdout: true
 }
 
 labels_4: {
@@ -54,6 +56,7 @@ labels_4: {
         for (var i = 0; i < 5; ++i)
             i < 3 || console.log(i);
     }
+    expect_stdout: true
 }
 
 labels_5: {

test/compress/loops.js

@@ -121,3 +121,340 @@ drop_if_else_break_4: {
         for (; bar() && (x(), y(), foo());) baz(), z(), k();
     }
 }
+
+parse_do_while_with_semicolon: {
+    options = { loops: false };
+    input: {
+        do {
+            x();
+        } while (false);y()
+    }
+    expect: {
+        do x(); while (false);y();
+    }
+}
+
+parse_do_while_without_semicolon: {
+    options = { loops: false };
+    input: {
+        do {
+            x();
+        } while (false)y()
+    }
+    expect: {
+        do x(); while (false);y();
+    }
+}
+
+
+keep_collapse_const_in_own_block_scope: {
+    options = {
+        join_vars: true,
+        loops: true
+    }
+    input: {
+        var i=2;
+        const c=5;
+        while(i--)
+            console.log(i);
+        console.log(c);
+    }
+    expect: {
+        var i=2;
+        const c=5;
+        for(;i--;)
+            console.log(i);
+        console.log(c);
+    }
+    expect_stdout: true
+}
+
+keep_collapse_const_in_own_block_scope_2: {
+    options = {
+        join_vars: true,
+        loops: true
+    }
+    input: {
+        const c=5;
+        var i=2; // Moves to loop, while it did not in previous test
+        while(i--)
+            console.log(i);
+        console.log(c);
+    }
+    expect: {
+        const c=5;
+        for(var i=2;i--;)
+            console.log(i);
+        console.log(c);
+    }
+    expect_stdout: true
+}
+
+evaluate: {
+    options = {
+        loops: true,
+        dead_code: true,
+        evaluate: true,
+    };
+    input: {
+        while (true) {
+            a();
+        }
+        while (false) {
+            b();
+        }
+        do {
+            c();
+        } while (true);
+        do {
+            d();
+        } while (false);
+    }
+    expect: {
+        for(;;)
+            a();
+        for(;;)
+            c();
+        // rule disabled due to issue_1532
+        do d(); while (false);
+    }
+}
+
+issue_1532: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        function f(x, y) {
+            do {
+                if (x) break;
+                foo();
+            } while (false);
+        }
+    }
+    expect: {
+        function f(x, y) {
+            do {
+                if (x) break;
+                foo();
+            } while (false);
+        }
+    }
+}
+
+issue_186: {
+    beautify = {
+        beautify: false,
+        screw_ie8: true,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: 'var x=3;if(foo())do{do{alert(x)}while(--x)}while(x);else bar();'
+}
+
+issue_186_ie8: {
+    beautify = {
+        beautify: false,
+        screw_ie8: false,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: 'var x=3;if(foo()){do{do{alert(x)}while(--x)}while(x)}else bar();'
+}
+
+issue_186_beautify: {
+    beautify = {
+        beautify: true,
+        screw_ie8: true,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: [
+        'var x = 3;',
+        '',
+        'if (foo()) do {',
+        '    do {',
+        '        alert(x);',
+        '    } while (--x);',
+        '} while (x); else bar();',
+    ]
+}
+
+issue_186_beautify_ie8: {
+    beautify = {
+        beautify: true,
+        screw_ie8: false,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: [
+        'var x = 3;',
+        '',
+        'if (foo()) {',
+        '    do {',
+        '        do {',
+        '            alert(x);',
+        '        } while (--x);',
+        '    } while (x);',
+        '} else bar();',
+    ]
+}
+
+issue_186_bracketize: {
+    beautify = {
+        beautify: false,
+        bracketize: true,
+        screw_ie8: true,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: 'var x=3;if(foo()){do{do{alert(x)}while(--x)}while(x)}else{bar()}'
+}
+
+issue_186_bracketize_ie8: {
+    beautify = {
+        beautify: false,
+        bracketize: true,
+        screw_ie8: false,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: 'var x=3;if(foo()){do{do{alert(x)}while(--x)}while(x)}else{bar()}'
+}
+
+issue_186_beautify_bracketize: {
+    beautify = {
+        beautify: true,
+        bracketize: true,
+        screw_ie8: true,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: [
+        'var x = 3;',
+        '',
+        'if (foo()) {',
+        '    do {',
+        '        do {',
+        '            alert(x);',
+        '        } while (--x);',
+        '    } while (x);',
+        '} else {',
+        '    bar();',
+        '}',
+    ]
+}
+
+issue_186_beautify_bracketize_ie8: {
+    beautify = {
+        beautify: true,
+        bracketize: true,
+        screw_ie8: false,
+    }
+    input: {
+        var x = 3;
+        if (foo())
+            do
+                do
+                    alert(x);
+                while (--x);
+            while (x);
+        else
+            bar();
+    }
+    expect_exact: [
+        'var x = 3;',
+        '',
+        'if (foo()) {',
+        '    do {',
+        '        do {',
+        '            alert(x);',
+        '        } while (--x);',
+        '    } while (x);',
+        '} else {',
+        '    bar();',
+        '}',
+    ]
+}
+
+issue_1648: {
+    options = {
+        join_vars: true,
+        loops: true,
+        passes: 2,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            x();
+            var b = 1;
+            while (1);
+        }
+    }
+    expect_exact: "function f(){for(x();1;);}"
+}

test/compress/max_line_len.js

@@ -0,0 +1,39 @@
+too_short: {
+    beautify = {
+        max_line_len: 10,
+    }
+    input: {
+        function f(a) {
+            return { c: 42, d: a(), e: "foo"};
+        }
+    }
+    expect_exact: [
+        'function f(a){',
+        'return{',
+        'c:42,',
+        'd:a(),',
+        'e:"foo"}}',
+    ]
+    expect_warnings: [
+        "WARN: Output exceeds 10 characters"
+    ]
+}
+
+just_enough: {
+    beautify = {
+        max_line_len: 14,
+    }
+    input: {
+        function f(a) {
+            return { c: 42, d: a(), e: "foo"};
+        }
+    }
+    expect_exact: [
+        'function f(a){',
+        'return{c:42,',
+        'd:a(),e:"foo"}',
+        '}',
+    ]
+    expect_warnings: [
+    ]
+}

test/compress/negate-iife.js

@@ -0,0 +1,418 @@
+negate_iife_1: {
+    options = {
+        negate_iife: true
+    };
+    input: {
+        (function(){ stuff() })();
+    }
+    expect: {
+        !function(){ stuff() }();
+    }
+}
+
+negate_iife_1_off: {
+    options = {
+        negate_iife: false,
+    };
+    input: {
+        (function(){ stuff() })();
+    }
+    expect_exact: '(function(){stuff()})();'
+}
+
+negate_iife_2: {
+    options = {
+        negate_iife: true
+    };
+    input: {
+        (function(){ return {} })().x = 10; // should not transform this one
+    }
+    expect: {
+        (function(){ return {} })().x = 10;
+    }
+}
+
+negate_iife_2_side_effects: {
+    options = {
+        negate_iife: true,
+        side_effects: true,
+    }
+    input: {
+        (function(){ return {} })().x = 10; // should not transform this one
+    }
+    expect: {
+        (function(){ return {} })().x = 10;
+    }
+}
+
+negate_iife_3: {
+    options = {
+        negate_iife: true,
+        conditionals: true
+    };
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        !function(){ return t }() ? console.log(false) : console.log(true);
+    }
+}
+
+negate_iife_3_evaluate: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        negate_iife: true,
+    }
+    input: {
+        (function(){ return true })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        console.log(true);
+    }
+    expect_stdout: true
+}
+
+negate_iife_3_side_effects: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        side_effects: true,
+    }
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        !function(){ return t }() ? console.log(false) : console.log(true);
+    }
+}
+
+negate_iife_3_off: {
+    options = {
+        negate_iife: false,
+        conditionals: true,
+    };
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        !function(){ return t }() ? console.log(false) : console.log(true);
+    }
+}
+
+negate_iife_3_off_evaluate: {
+    options = {
+        conditionals: true,
+        evaluate: true,
+        negate_iife: false,
+    }
+    input: {
+        (function(){ return true })() ? console.log(true) : console.log(false);
+    }
+    expect: {
+        console.log(true);
+    }
+    expect_stdout: true
+}
+
+negate_iife_4: {
+    options = {
+        negate_iife: true,
+        conditionals: true,
+        sequences: true
+    };
+    input: {
+        (function(){ return t })() ? console.log(true) : console.log(false);
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function(){ return t }() ? console.log(false) : console.log(true), function(){
+            console.log("something");
+        }();
+    }
+}
+
+sequence_off: {
+    options = {
+        negate_iife: false,
+        conditionals: true,
+        sequences: true,
+        passes: 2,
+    };
+    input: {
+        function f() {
+            (function(){ return t })() ? console.log(true) : console.log(false);
+            (function(){
+                console.log("something");
+            })();
+        }
+        function g() {
+            (function(){
+                console.log("something");
+            })();
+            (function(){ return t })() ? console.log(true) : console.log(false);
+        }
+    }
+    expect: {
+        function f() {
+            !function(){ return t }() ? console.log(false) : console.log(true), function(){
+                console.log("something");
+            }();
+        }
+        function g() {
+            (function(){
+                console.log("something");
+            })(), function(){ return t }() ? console.log(true) : console.log(false);
+        }
+    }
+}
+
+negate_iife_5: {
+    options = {
+        negate_iife: true,
+        sequences: true,
+        conditionals: true,
+    };
+    input: {
+        if ((function(){ return t })()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function(){ return t }() ? bar(false) : foo(true), function(){
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_5_off: {
+    options = {
+        negate_iife: false,
+        sequences: true,
+        conditionals: true,
+    };
+    input: {
+        if ((function(){ return t })()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function(){
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function(){ return t }() ? bar(false) : foo(true), function(){
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_nested: {
+    options = {
+        negate_iife: true,
+        sequences: true,
+        conditionals: true,
+    };
+    input: {
+        function Foo(f) {
+            this.f = f;
+        }
+        new Foo(function() {
+            (function(x) {
+                (function(y) {
+                    console.log(y);
+                })(x);
+            })(7);
+        }).f();
+    }
+    expect: {
+        function Foo(f) {
+            this.f = f;
+        }
+        new Foo(function() {
+            !function(x) {
+                !function(y) {
+                    console.log(y);
+                }(x);
+            }(7);
+        }).f();
+    }
+    expect_stdout: true
+}
+
+negate_iife_nested_off: {
+    options = {
+        negate_iife: false,
+        sequences: true,
+        conditionals: true,
+    };
+    input: {
+        function Foo(f) {
+            this.f = f;
+        }
+        new Foo(function() {
+            (function(x) {
+                (function(y) {
+                    console.log(y);
+                })(x);
+            })(7);
+        }).f();
+    }
+    expect: {
+        function Foo(f) {
+            this.f = f;
+        }
+        new Foo(function() {
+            (function(x) {
+                (function(y) {
+                    console.log(y);
+                })(x);
+            })(7);
+        }).f();
+    }
+    expect_stdout: true
+}
+
+negate_iife_issue_1073: {
+    options = {
+        negate_iife: true,
+        sequences: true,
+        conditionals: true,
+    };
+    input: {
+        new (function(a) {
+            return function Foo() {
+                this.x = a;
+                console.log(this);
+            };
+        }(7))();
+    }
+    expect: {
+        new (function(a) {
+            return function Foo() {
+                this.x = a,
+                console.log(this);
+            };
+        }(7))();
+    }
+    expect_stdout: true
+}
+
+issue_1254_negate_iife_false: {
+    options = {
+        negate_iife: false,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()();
+    }
+    expect_exact: '(function(){return function(){console.log("test")}})()();'
+    expect_stdout: true
+}
+
+issue_1254_negate_iife_true: {
+    options = {
+        negate_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()();
+    }
+    expect_exact: '!function(){return function(){console.log("test")}}()();'
+    expect_stdout: true
+}
+
+issue_1254_negate_iife_nested: {
+    options = {
+        negate_iife: true,
+    }
+    input: {
+        (function() {
+            return function() {
+                console.log('test')
+            };
+        })()()()()();
+    }
+    expect_exact: '!function(){return function(){console.log("test")}}()()()()();'
+    expect_stdout: true
+}
+
+issue_1288: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        side_effects: false,
+    };
+    input: {
+        if (w) ;
+        else {
+            (function f() {})();
+        }
+        if (!x) {
+            (function() {
+                x = {};
+            })();
+        }
+        if (y)
+            (function() {})();
+        else
+            (function(z) {
+                return z;
+            })(0);
+    }
+    expect: {
+        w || !function f() {}();
+        x || !function() {
+            x = {};
+        }();
+        y ? !function() {}() : !function(z) {
+            return z;
+        }(0);
+    }
+}
+
+issue_1288_side_effects: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        side_effects: true,
+    }
+    input: {
+        if (w) ;
+        else {
+            (function f() {})();
+        }
+        if (!x) {
+            (function() {
+                x = {};
+            })();
+        }
+        if (y)
+            (function() {})();
+        else
+            (function(z) {
+                return z;
+            })(0);
+    }
+    expect: {
+        w;
+        x || function() {
+            x = {};
+        }();
+        y;
+    }
+}

test/compress/new.js

@@ -0,0 +1,100 @@
+new_statement: {
+    input: {
+        new x(1);
+        new x(1)(2);
+        new x(1)(2)(3);
+        new new x(1);
+        new new x(1)(2);
+        new (new x(1))(2);
+        (new new x(1))(2);
+    }
+    expect_exact: "new x(1);new x(1)(2);new x(1)(2)(3);new new x(1);new new x(1)(2);new new x(1)(2);(new new x(1))(2);"
+}
+
+new_statements_2: {
+    input: {
+        new x;
+        new new x;
+        new new new x;
+        new true;
+        new (0);
+        new (!0);
+        new (bar = function(foo) {this.foo=foo;})(123);
+        new (bar = function(foo) {this.foo=foo;})();
+    }
+    expect_exact: "new x;new(new x);new(new(new x));new true;new 0;new(!0);new(bar=function(foo){this.foo=foo})(123);new(bar=function(foo){this.foo=foo});"
+}
+
+new_statements_3: {
+    input: {
+        new (function(foo){this.foo=foo;})(1);
+        new (function(foo){this.foo=foo;})();
+        new (function test(foo){this.foo=foo;})(1);
+        new (function test(foo){this.foo=foo;})();
+    }
+    expect_exact: "new function(foo){this.foo=foo}(1);new function(foo){this.foo=foo};new function test(foo){this.foo=foo}(1);new function test(foo){this.foo=foo};"
+}
+
+new_with_rewritten_true_value: {
+    options = { booleans: true }
+    input: {
+        new true;
+    }
+    expect_exact: "new(!0);"
+}
+
+new_with_many_parameters: {
+    input: {
+        new foo.bar("baz");
+        new x(/123/, 456);
+    }
+    expect_exact: 'new foo.bar("baz");new x(/123/,456);'
+}
+
+new_constructor_with_unary_arguments: {
+    input: {
+        new x();
+        new x(-1);
+        new x(-1, -2);
+        new x(void 1, +2, -3, ~4, !5, --a, ++b, c--, d++, typeof e, delete f);
+        new (-1);     // should parse despite being invalid at runtime.
+        new (-1)();   // should parse despite being invalid at runtime.
+        new (-1)(-2); // should parse despite being invalid at runtime.
+    }
+    expect_exact: "new x;new x(-1);new x(-1,-2);new x(void 1,+2,-3,~4,!5,--a,++b,c--,d++,typeof e,delete f);new(-1);new(-1);new(-1)(-2);"
+}
+
+call_with_unary_arguments: {
+    input: {
+        x();
+        x(-1);
+        x(-1, -2);
+        x(void 1, +2, -3, ~4, !5, --a, ++b, c--, d++, typeof e, delete f);
+        (-1)();   // should parse despite being invalid at runtime.
+        (-1)(-2); // should parse despite being invalid at runtime.
+    }
+    expect_exact: "x();x(-1);x(-1,-2);x(void 1,+2,-3,~4,!5,--a,++b,c--,d++,typeof e,delete f);(-1)();(-1)(-2);"
+}
+
+new_with_unary_prefix: {
+    input: {
+        var bar = (+new Date()).toString(32);
+    }
+    expect_exact: 'var bar=(+new Date).toString(32);';
+}
+
+new_with_assignement_expression: {
+    options = {
+        evaluate: true
+    }
+    input: {
+        var a;
+        new x(a = 5 * 2, b = [1, 2, 3], c = {a: "a", b: "b", cd: "c" + "d"});
+        new y([a, b] = [3, 4]);
+    }
+    expect: {
+        var a;
+        new x(a = 10, b = [1, 2, 3], c = {a: "a", b: "b", cd: "cd"});
+        new y([a, b] = [3, 4]);
+    }
+}