v3.3.13

improve test/run-test.js performance (#2971 )
- allow reuse of contextified sandbox - minimise bottleneck from `vm.createContext()`
2018-03-04 07:38:49 +00:00 · 2018-03-04 04:50:00 +08:00 · 2018-03-02 11:22:09 +08:00 · 2018-03-02 04:04:29 +08:00 · 2018-02-28 23:34:48 +08:00 · 2018-02-28 22:02:24 +08:00
34 changed files with 3547 additions and 444 deletions
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -0,0 +1,61 @@
+Contributing
+============
+
+## Documentation
+
+Every new feature and API change should be accompanied by a README additon.
+
+## Testing
+
+All features and bugs should have tests that verify the fix. You can run all
+tests using `npm test`.
+
+The most common type of test are tests that verify input and output of the
+Uglify transforms. These tests exist in `test/compress`. New tests can be added
+either to an existing file or in a new file `issue-xxx.js`.
+
+Tests that cannot be expressed as a simple AST can be found in `test/mocha`.
+
+## Code style
+
+- File encoding must be `UTF-8`.
+- `LF` is always used as a line ending.
+- Statements end with semicolons.
+- Indentation uses 4 spaces, switch `case` 2 spaces.
+- Identifiers use `snake_case`.
+- Strings use double quotes (`"`).
+- Use a trailing comma for multiline array and object literals to minimize diffs.
+- The Uglify code only uses ES5, even in the `harmony` branch.
+- Line length should be at most 80 cols, except when it is easier to read a
+  longer line.
+- If both sides of a comparison are of the same type, `==` and `!=` are used.
+- Multiline conditions place `&&` and `||` first on the line.
+
+**Example feature**
+
+```js
+OPT(AST_Debugger, function(self, compressor) {
+    if (compressor.option("drop_debugger"))
+        return make_node(AST_EmptyStatement, self);
+    return self;
+});
+```
+
+**Example test case**
+
+```js
+drop_debugger: {
+    options = {
+        drop_debugger: true,
+    }
+    input: {
+        debugger;
+        if (foo) debugger;
+    }
+    expect: {
+        if (foo);
+    }
+}
+```
+
+
--- a/2
+++ b/2
@@ -1,6 +1,6 @@
 UglifyJS is released under the BSD license:

-Copyright 2012-2013 (c) Mihai Bazon <mihai.bazon@gmail.com>
+Copyright 2012-2018 (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
--- a/README.md
+++ b/README.md
@@ -598,6 +598,9 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u

 ## Compress options

+- `arguments` (default: `true`) -- replace `arguments[index]` with function
+  parameter name whenever possible.
+
 - `booleans` (default: `true`) -- various optimizations for boolean context,
  for example `!!a ? b : c → a ? b : c`

@@ -605,8 +608,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u
  side effects permitting.

 - `comparisons` (default: `true`) -- apply certain optimizations to binary nodes,
-  e.g. `!(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.
+  e.g. `!(a <= b) → a > b`, attempts to negate binary nodes, e.g.
+  `a = !b && !c && !d && !e → a=!(b||c||d||e)` etc.

 - `conditionals` (default: `true`) -- apply optimizations for `if`-s and conditional
  expressions
@@ -730,12 +733,8 @@ If you're using the `X-SourceMap` header instead, you can just omit `sourceMap.u

 - `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_comps` (default: `false`) -- compress expressions like `a <= b` assuming
+  none of the operands can be (coerced to) `NaN`.

 - `unsafe_Function` (default: `false`) -- compress and mangle `Function(args, code)`
  when both `args` and `code` are string literals.
@@ -1102,3 +1101,27 @@ To enable fast minify mode with the API use:
 ```js
 UglifyJS.minify(code, { compress: false, mangle: true });
 ```
+
+#### Source maps and debugging
+
+Various `compress` transforms that simplify, rearrange, inline and remove code
+are known to have an adverse effect on debugging with source maps. This is
+expected as code is optimized and mappings are often simply not possible as
+some code no longer exists. For highest fidelity in source map debugging
+disable the Uglify `compress` option and just use `mangle`.
+
+### Compiler assumptions
+
+To allow for better optimizations, the compiler makes various assumptions:
+
+- `.toString()` and `.valueOf()` don't have side effects, and for built-in
+  objects they have not been overridden.
+- `undefined`, `NaN` and `Infinity` have not been externally redefined.
+- `arguments.callee`, `arguments.caller` and `Function.prototype.caller` are not used.
+- The code doesn't expect the contents of `Function.prototype.toString()` or
+  `Error.prototype.stack` to be anything in particular.
+- Getting and setting properties on a plain object does not cause other side effects
+  (using `.watch()` or `Proxy`).
+- Object properties can be added, removed and modified (not prevented with
+  `Object.defineProperty()`, `Object.defineProperties()`, `Object.freeze()`,
+  `Object.preventExtensions()` or `Object.seal()`).
--- a/lib/compress.js
+++ b/lib/compress.js
--- a/lib/minify.js
+++ b/lib/minify.js
@@ -150,7 +150,6 @@ function minify(files, options) {
        if (options.mangle) toplevel.figure_out_scope(options.mangle);
        if (timings) timings.mangle = Date.now();
        if (options.mangle) {
-            base54.reset();
            toplevel.compute_char_frequency(options.mangle);
            toplevel.mangle_names(options.mangle);
        }
--- a/lib/output.js
+++ b/lib/output.js
@@ -576,6 +576,7 @@ function OutputStream(options) {
        indentation     : function() { return indentation },
        current_width   : function() { return current_col - indentation },
        should_break    : function() { return options.width && this.current_width() >= options.width },
+        has_parens      : function() { return OUTPUT.slice(-1) == "(" },
        newline         : newline,
        print           : print,
        space           : space,
@@ -683,7 +684,7 @@ function OutputStream(options) {
    // a function expression needs parens around it when it's provably
    // the first token to appear in a statement.
    PARENS(AST_Function, function(output){
-        if (first_in_statement(output)) {
+        if (!output.has_parens() && first_in_statement(output)) {
            return true;
        }

@@ -704,7 +705,9 @@ function OutputStream(options) {

    // same goes for an object literal, because otherwise it would be
    // interpreted as a block of code.
-    PARENS(AST_Object, first_in_statement);
+    PARENS(AST_Object, function(output){
+        return !output.has_parens() && first_in_statement(output);
+    });

    PARENS(AST_Unary, function(output){
        var p = output.parent();
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -83,8 +83,9 @@ SymbolDef.prototype = {
            var def;
            if (def = this.redefined()) {
                this.mangled_name = def.mangled_name || def.name;
-            } else
-                this.mangled_name = s.next_mangled(options, this);
+            } else {
+                this.mangled_name = next_mangled_name(s, options, this);
+            }
            if (this.global && cache) {
                cache.set(this.name, this.mangled_name);
            }
@@ -168,8 +169,8 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
                var def = scope.find_variable(node);
                if (node.thedef !== def) {
                    node.thedef = def;
-                    node.reference(options);
                }
+                node.reference(options);
            }
        }
        else if (node instanceof AST_SymbolCatch) {
@@ -305,7 +306,7 @@ AST_Scope.DEFMETHOD("find_variable", function(name){

 AST_Scope.DEFMETHOD("def_function", function(symbol, init){
    var def = this.def_variable(symbol, init);
-    if (!def.init) def.init = init;
+    if (!def.init || def.init instanceof AST_Defun) def.init = init;
    this.functions.set(symbol.name, def);
    return def;
 });
@@ -325,56 +326,59 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol, init){
    return symbol.thedef = def;
 });

-function next_mangled(scope, options) {
-    var ext = scope.enclosed;
-    out: while (true) {
-        var m = base54(++scope.cname);
-        if (!is_identifier(m)) continue; // skip over "do"
-
-        // https://github.com/mishoo/UglifyJS2/issues/242 -- do not
-        // shadow a name reserved from mangling.
-        if (member(m, options.reserved)) 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 = ext.length; --i >= 0;) {
-            var sym = ext[i];
-            var name = sym.mangled_name || (sym.unmangleable(options) && sym.name);
-            if (m == name) continue out;
-        }
-        return m;
+function names_in_use(scope, options) {
+    var names = scope.names_in_use;
+    if (!names) {
+        scope.names_in_use = names = Object.create(scope.mangled_names || null);
+        scope.cname_holes = [];
+        scope.enclosed.forEach(function(def) {
+            if (def.unmangleable(options)) names[def.name] = true;
+        });
    }
+    return names;
 }

-AST_Scope.DEFMETHOD("next_mangled", function(options){
-    return next_mangled(this, options);
-});
-
-AST_Toplevel.DEFMETHOD("next_mangled", function(options){
-    var name;
-    do {
-        name = next_mangled(this, options);
-    } while (member(name, this.mangled_names));
-    return name;
-});
-
-AST_Function.DEFMETHOD("next_mangled", function(options, def){
+function next_mangled_name(scope, options, def) {
+    var in_use = names_in_use(scope, options);
+    var holes = scope.cname_holes;
+    var names = Object.create(null);
    // #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();
-
+    if (scope instanceof AST_Function && scope.name && def.orig[0] instanceof AST_SymbolFunarg) {
+        var tricky_def = scope.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 = next_mangled(this, options);
-        if (!tricky_name || tricky_name != name)
+        names[tricky_def.mangled_name || tricky_def.name] = true;
+    }
+    var scopes = [ scope ];
+    def.references.forEach(function(sym) {
+        var scope = sym.scope;
+        do {
+            if (scopes.indexOf(scope) < 0) {
+                for (var name in names_in_use(scope, options)) {
+                    names[name] = true;
+                }
+                scopes.push(scope);
+            } else break;
+        } while (scope = scope.parent_scope);
+    });
+    var name;
+    for (var i = 0, len = holes.length; i < len; i++) {
+        name = base54(holes[i]);
+        if (names[name]) continue;
+        holes.splice(i, 1);
+        scope.names_in_use[name] = true;
        return name;
    }
-});
+    while (true) {
+        name = base54(++scope.cname);
+        if (in_use[name] || !is_identifier(name) || member(name, options.reserved)) continue;
+        if (!names[name]) break;
+        holes.push(scope.cname);
+    }
+    scope.names_in_use[name] = true;
+    return name;
+}

 AST_Symbol.DEFMETHOD("unmangleable", function(options){
    var def = this.definition();
@@ -397,7 +401,7 @@ AST_Symbol.DEFMETHOD("global", function(){
    return this.definition().global;
 });

-AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) {
+function _default_mangler_options(options) {
    options = defaults(options, {
        eval        : false,
        ie8         : false,
@@ -409,28 +413,25 @@ AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options) {
    // Never mangle arguments
    push_uniq(options.reserved, "arguments");
    return options;
-});
+}

 AST_Toplevel.DEFMETHOD("mangle_names", function(options){
-    options = this._default_mangler_options(options);
+    options = _default_mangler_options(options);

    // 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 = [];

-    var mangled_names = this.mangled_names = [];
-    if (options.cache) {
-        this.globals.each(collect);
-        if (options.cache.props) {
+    if (options.cache && options.cache.props) {
+        var mangled_names = this.mangled_names = Object.create(null);
        options.cache.props.each(function(mangled_name) {
-                push_uniq(mangled_names, mangled_name);
+            mangled_names[mangled_name] = true;
        });
    }
-    }

+    var redefined = [];
    var tw = new TreeWalker(function(node, descend){
        if (node instanceof AST_LabeledStatement) {
            // lname is incremented when we get to the AST_Label
@@ -440,8 +441,12 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
            return true;        // don't descend again in TreeWalker
        }
        if (node instanceof AST_Scope) {
-            node.variables.each(collect);
-            return;
+            descend();
+            if (options.cache && node instanceof AST_Toplevel) {
+                node.globals.each(mangle);
+            }
+            node.variables.each(mangle);
+            return true;
        }
        if (node instanceof AST_Label) {
            var name;
@@ -449,17 +454,28 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
            node.mangled_name = name;
            return true;
        }
-        if (!options.ie8 && node instanceof AST_SymbolCatch) {
-            to_mangle.push(node.definition());
-            return;
+        if (!options.ie8 && node instanceof AST_Catch) {
+            var def = node.argname.definition();
+            var redef = def.redefined();
+            if (redef) {
+                redefined.push(def);
+                def.references.forEach(function(ref) {
+                    ref.thedef = redef;
+                    ref.reference(options);
+                    ref.thedef = def;
+                });
+            }
+            descend();
+            if (!redef) mangle(def);
+            return true;
        }
    });
    this.walk(tw);
-    to_mangle.forEach(function(def){ def.mangle(options) });
+    redefined.forEach(mangle);

-    function collect(symbol) {
-        if (!member(symbol.name, options.reserved)) {
-            to_mangle.push(symbol);
+    function mangle(def) {
+        if (!member(def.name, options.reserved)) {
+            def.mangle(options);
        }
    }
 });
@@ -490,7 +506,7 @@ AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
 AST_Toplevel.DEFMETHOD("expand_names", function(options) {
    base54.reset();
    base54.sort();
-    options = this._default_mangler_options(options);
+    options = _default_mangler_options(options);
    var avoid = this.find_colliding_names(options);
    var cname = 0;
    this.globals.each(rename);
@@ -528,7 +544,8 @@ AST_Sequence.DEFMETHOD("tail_node", function() {
 });

 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
-    options = this._default_mangler_options(options);
+    options = _default_mangler_options(options);
+    base54.reset();
    try {
        AST_Node.prototype.print = function(stream, force_parens) {
            this._print(stream, force_parens);
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
  "homepage": "http://lisperator.net/uglifyjs",
  "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
  "license": "BSD-2-Clause",
-  "version": "3.3.8",
+  "version": "3.3.13",
  "engines": {
    "node": ">=0.8.0"
  },
@@ -24,13 +24,13 @@
    "LICENSE"
  ],
  "dependencies": {
-    "commander": "~2.13.0",
+    "commander": "~2.14.1",
    "source-map": "~0.6.1"
  },
  "devDependencies": {
-    "acorn": "~5.3.0",
+    "acorn": "~5.4.1",
    "mocha": "~3.5.1",
-    "semver": "~5.4.1"
+    "semver": "~5.5.0"
  },
  "scripts": {
    "test": "node test/run-tests.js"
--- a/test/benchmark.js
+++ b/test/benchmark.js
@@ -28,6 +28,7 @@ var remaining = 2 * urls.length;
 function done() {
    if (!--remaining) {
        var failures = [];
+        var sum = { input: 0, output: 0, gzip: 0 };
        urls.forEach(function(url) {
            var info = results[url];
            console.log();
@@ -40,6 +41,9 @@ function done() {
            if (info.code) {
                failures.push(url);
            }
+            sum.input += info.input;
+            sum.output += info.output;
+            sum.gzip += info.gzip;
        });
        if (failures.length) {
            console.error("Benchmark failed:");
@@ -47,6 +51,13 @@ function done() {
                console.error(url);
            });
            process.exit(1);
+        } else {
+            console.log();
+            console.log("Subtotal");
+            console.log();
+            console.log("Original:", sum.input, "bytes");
+            console.log("Uglified:", sum.output, "bytes");
+            console.log("GZipped: ", sum.gzip, "bytes");
        }
    }
 }
--- a/test/compress/arguments.js
+++ b/test/compress/arguments.js
@@ -0,0 +1,119 @@
+replace_index: {
+    options = {
+        arguments: true,
+        evaluate: true,
+        properties: true,
+    }
+    input: {
+        console.log(arguments && arguments[0]);
+        (function() {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+    }
+    expect: {
+        console.log(arguments && arguments[0]);
+        (function() {
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(b, b, arguments.foo);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+    }
+    expect_stdout: [
+        "undefined",
+        "42 42 undefined",
+        "42 42 undefined",
+        "a a undefined",
+        "42 42 undefined",
+    ]
+}
+
+replace_index_keep_fargs: {
+    options = {
+        arguments: true,
+        evaluate: true,
+        keep_fargs: false,
+        properties: true,
+    }
+    input: {
+        console.log(arguments && arguments[0]);
+        (function() {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments["1"], arguments["foo"]);
+        })("bar", 42);
+    }
+    expect: {
+        console.log(arguments && arguments[0]);
+        (function(argument_0, argument_1) {
+            console.log(argument_1, argument_1, arguments.foo);
+        })("bar", 42);
+        (function(a, b) {
+            console.log(b, b, arguments.foo);
+        })("bar", 42);
+        (function(arguments) {
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+        (function() {
+            var arguments;
+            console.log(arguments[1], arguments[1], arguments.foo);
+        })("bar", 42);
+    }
+    expect_stdout: [
+        "undefined",
+        "42 42 undefined",
+        "42 42 undefined",
+        "a a undefined",
+        "42 42 undefined",
+    ]
+}
+
+modified: {
+    options = {
+        arguments: true,
+    }
+    input: {
+        (function(a, b) {
+            var c = arguments[0];
+            var d = arguments[1];
+            a = "foo";
+            b++;
+            console.log(a, b, c, d, arguments[0], arguments[1]);
+        })("bar", 42);
+    }
+    expect: {
+        (function(a, b) {
+            var c = a;
+            var d = b;
+            a = "foo";
+            b++;
+            console.log(a, b, c, d, a, b);
+        })("bar", 42);
+    }
+    expect_stdout: "foo 43 bar 42 foo 43"
+}
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
--- a/test/compress/comparing.js
+++ b/test/compress/comparing.js
@@ -1,62 +1,42 @@
-keep_comparisons: {
+comparisons: {
    options = {
        comparisons: true,
-        unsafe_comps: false
    }
    input: {
-        var obj1 = {
-            valueOf: function() {triggeredFirst();}
-        }
-        var obj2 = {
-            valueOf: function() {triggeredSecond();}
-        }
+        var obj1, obj2;
        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 obj1, obj2;
        var result1 = obj1 <= obj2;
        var result2 = obj1 <  obj2;
-        var result3 = obj1 >= obj2;
-        var result4 = obj1 >  obj2;
+        var result3 = obj2 <= obj1;
+        var result4 = obj2 <  obj1;
    }
 }

-keep_comparisons_with_unsafe_comps: {
+unsafe_comps: {
    options = {
        comparisons: true,
-        unsafe_comps: true
+        conditionals: 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;
+        var obj1, obj2;
+        obj1 <= obj2 ? f1() : g1();
+        obj1 <  obj2 ? f2() : g2();
+        obj1 >= obj2 ? f3() : g3();
+        obj1 >  obj2 ? f4() : g4();
    }
    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;
+        var obj1, obj2;
+        obj2 <  obj1 ? g1() : f1();
+        obj1 <  obj2 ? f2() : g2();
+        obj1 <  obj2 ? g3() : f3();
+        obj2 <  obj1 ? f4() : g4();
    }
 }

@@ -112,3 +92,206 @@ self_comparison_2: {
    }
    expect_stdout: "false true"
 }
+
+issue_2857_1: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f1(a) {
+            a === undefined || a === null;
+            a === undefined || a !== null;
+            a !== undefined || a === null;
+            a !== undefined || a !== null;
+            a === undefined && a === null;
+            a === undefined && a !== null;
+            a !== undefined && a === null;
+            a !== undefined && a !== null;
+        }
+        function f2(a) {
+            a === null || a === undefined;
+            a === null || a !== undefined;
+            a !== null || a === undefined;
+            a !== null || a !== undefined;
+            a === null && a === undefined;
+            a === null && a !== undefined;
+            a !== null && a === undefined;
+            a !== null && a !== undefined;
+        }
+    }
+    expect: {
+        function f1(a) {
+            null == a;
+            void 0 === a || null !== a;
+            void 0 !== a || null === a;
+            void 0 !== a || null !== a;
+            void 0 === a && null === a;
+            void 0 === a && null !== a;
+            void 0 !== a && null === a;
+            null != a;
+        }
+        function f2(a) {
+            null == a;
+            null === a || void 0 !== a;
+            null !== a || void 0 === a;
+            null !== a || void 0 !== a;
+            null === a && void 0 === a;
+            null === a && void 0 !== a;
+            null !== a && void 0 === a;
+            null != a;
+        }
+    }
+}
+
+issue_2857_2: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            a === undefined || a === null || p;
+            a === undefined || a !== null || p;
+            a !== undefined || a === null || p;
+            a !== undefined || a !== null || p;
+            a === undefined && a === null || p;
+            a === undefined && a !== null || p;
+            a !== undefined && a === null || p;
+            a !== undefined && a !== null || p;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            null == a || p;
+            void 0 === a || null !== a || p;
+            void 0 !== a || null === a || p;
+            void 0 !== a || null !== a || p;
+            void 0 === a && null === a || p;
+            void 0 === a && null !== a || p;
+            void 0 !== a && null === a || p;
+            null != a || p;
+        }
+    }
+}
+
+issue_2857_3: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            a === undefined || a === null && p;
+            a === undefined || a !== null && p;
+            a !== undefined || a === null && p;
+            a !== undefined || a !== null && p;
+            a === undefined && a === null && p;
+            a === undefined && a !== null && p;
+            a !== undefined && a === null && p;
+            a !== undefined && a !== null && p;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            void 0 === a || null === a && p;
+            void 0 === a || null !== a && p;
+            void 0 !== a || null === a && p;
+            void 0 !== a || null !== a && p;
+            void 0 === a && null === a && p;
+            void 0 === a && null !== a && p;
+            void 0 !== a && null === a && p;
+            null != a && p;
+        }
+    }
+}
+
+issue_2857_4: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            p || a === undefined || a === null;
+            p || a === undefined || a !== null;
+            p || a !== undefined || a === null;
+            p || a !== undefined || a !== null;
+            p || a === undefined && a === null;
+            p || a === undefined && a !== null;
+            p || a !== undefined && a === null;
+            p || a !== undefined && a !== null;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            p || null == a;
+            p || void 0 === a || null !== a;
+            p || void 0 !== a || null === a;
+            p || void 0 !== a || null !== a;
+            p || void 0 === a && null === a;
+            p || void 0 === a && null !== a;
+            p || void 0 !== a && null === a;
+            p || null != a;
+        }
+    }
+}
+
+issue_2857_5: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        function f(a, p) {
+            p && a === undefined || a === null;
+            p && a === undefined || a !== null;
+            p && a !== undefined || a === null;
+            p && a !== undefined || a !== null;
+            p && a === undefined && a === null;
+            p && a === undefined && a !== null;
+            p && a !== undefined && a === null;
+            p && a !== undefined && a !== null;
+        }
+    }
+    expect: {
+        function f(a, p) {
+            p && void 0 === a || null === a;
+            p && void 0 === a || null !== a;
+            p && void 0 !== a || null === a;
+            p && void 0 !== a || null !== a;
+            p && void 0 === a && null === a;
+            p && void 0 === a && null !== a;
+            p && void 0 !== a && null === a;
+            p && null != a;
+        }
+    }
+}
+
+issue_2857_6: {
+    options = {
+        comparisons: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        function f(a) {
+            if (({}).b === undefined || {}.b === null)
+                return a.b !== undefined && a.b !== null;
+        }
+        console.log(f({
+            a: [ null ],
+            get b() {
+                return this.a.shift();
+            }
+        }));
+    }
+    expect: {
+        function f(a) {
+            if (null == {}.b)
+                return void 0 !== a.b && null !== a.b;
+        }
+        console.log(f({
+            a: [ null ],
+            get b() {
+                return this.a.shift();
+            }
+        }));
+    }
+    expect_stdout: "true"
+}
--- a/test/compress/conditionals.js
+++ b/test/compress/conditionals.js
@@ -332,7 +332,7 @@ cond_7: {
        x = 'foo';
        x = 'foo';
        x = (condition(), 20);
-        x = z ? 'fuji' : (condition(), 'fuji');
+        x = (z || condition(), 'fuji');
        x = (condition(), 'foobar');
        x = y ? a : b;
        x = y ? 'foo' : 'fo';
--- a/test/compress/dead-code.js
+++ b/test/compress/dead-code.js
@@ -879,3 +879,66 @@ unsafe_builtin: {
        z;
    }
 }
+
+issue_2860_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a ^= 1;
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            return 1 ^ a;
+        }());
+    }
+    expect_stdout: "1"
+}
+
+issue_2860_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a ^= 1;
+        }());
+    }
+    expect: {
+        console.log(1);
+    }
+    expect_stdout: "1"
+}
+
+issue_2929: {
+    options = {
+        dead_code: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                return null.p = a = 1;
+            } catch (e) {
+                return a ? "PASS" : "FAIL";
+            }
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                return null.p = a = 1;
+            } catch (e) {
+                return a ? "PASS" : "FAIL";
+            }
+        }());
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/drop-unused.js
+++ b/test/compress/drop-unused.js
@@ -1692,3 +1692,96 @@ issue_2768: {
    }
    expect_stdout: "PASS undefined"
 }
+
+issue_2846: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            var a = 0;
+            b && b(a);
+            return a++;
+        }
+        var c = f();
+        console.log(c);
+    }
+    expect: {
+        var c = function(a, b) {
+            a = 0;
+            b && b(a);
+            return a++;
+        }();
+        console.log(c);
+    }
+    expect_stdout: "0"
+}
+
+issue_805_1: {
+    options = {
+        inline: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            var unused = function() {};
+            unused.prototype[a()] = 42;
+            (unused.prototype.bar = function() {
+                console.log("bar");
+            })();
+            return unused;
+        })(function() {
+            console.log("foo");
+            return "foo";
+        });
+    }
+    expect: {
+        console.log("foo"),
+        console.log("bar");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+}
+
+issue_805_2: {
+    options = {
+        inline: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        (function(a) {
+            function unused() {}
+            unused.prototype[a()] = 42;
+            (unused.prototype.bar = function() {
+                console.log("bar");
+            })();
+            return unused;
+        })(function() {
+            console.log("foo");
+            return "foo";
+        });
+    }
+    expect: {
+        console.log("foo"),
+        console.log("bar");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+    ]
+}
--- a/test/compress/evaluate.js
+++ b/test/compress/evaluate.js
@@ -1374,3 +1374,195 @@ issue_2822: {
    }
    expect_stdout: "PASS"
 }
+
+string_case: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log("İ".toLowerCase().charCodeAt(0));
+        console.log("I".toLowerCase().charCodeAt(0));
+        console.log("Ş".toLowerCase().charCodeAt(0));
+        console.log("Ğ".toLowerCase().charCodeAt(0));
+        console.log("Ü".toLowerCase().charCodeAt(0));
+        console.log("Ö".toLowerCase().charCodeAt(0));
+        console.log("Ç".toLowerCase().charCodeAt(0));
+        console.log("i".toUpperCase().charCodeAt(0));
+        console.log("ı".toUpperCase().charCodeAt(0));
+        console.log("ş".toUpperCase().charCodeAt(0));
+        console.log("ğ".toUpperCase().charCodeAt(0));
+        console.log("ü".toUpperCase().charCodeAt(0));
+        console.log("ö".toUpperCase().charCodeAt(0));
+        console.log("ç".toUpperCase().charCodeAt(0));
+    }
+    expect: {
+        console.log(105);
+        console.log(105);
+        console.log(351);
+        console.log(287);
+        console.log(252);
+        console.log(246);
+        console.log(231);
+        console.log(73);
+        console.log(73);
+        console.log(350);
+        console.log(286);
+        console.log(220);
+        console.log(214);
+        console.log(199);
+    }
+    expect_stdout: [
+        "105",
+        "105",
+        "351",
+        "287",
+        "252",
+        "246",
+        "231",
+        "73",
+        "73",
+        "350",
+        "286",
+        "220",
+        "214",
+        "199",
+    ]
+}
+
+issue_2916_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        var c = "PASS";
+        (function(a, b) {
+            (function(d) {
+                d[0] = 1;
+            })(b);
+            a == b && (c = "FAIL");
+        })("", []);
+        console.log(c);
+    }
+    expect: {
+        var c = "PASS";
+        (function(a, b) {
+            (function(d) {
+                d[0] = 1;
+            })(b);
+            a == b && (c = "FAIL");
+        })("", []);
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2916_2: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        side_effects: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var c = "FAIL";
+        (function(b) {
+            (function(d) {
+                d[0] = 1;
+            })(b);
+            +b && (c = "PASS");
+        })([]);
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function(b) {
+            b[0] = 1;
+            +b && (c = "PASS");
+        })([]);
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2919: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log([ function() {} ].toString());
+    }
+    expect: {
+        console.log("function(){}");
+    }
+}
+
+issue_2926_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unsafe: true,
+    }
+    input: {
+        (function f(a) {
+            console.log(f.name.length, f.length);
+        })();
+    }
+    expect: {
+        (function f(a) {
+            console.log(1, 1);
+        })();
+    }
+    expect_stdout: "1 1"
+}
+
+issue_2926_2: {
+    options = {
+        evaluate: true,
+        unsafe: true,
+    }
+    input: {
+        console.log(typeof function() {}.valueOf());
+    }
+    expect: {
+        console.log("function");
+    }
+    expect_stdout: "function"
+}
+
+issue_2968: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var c = "FAIL";
+        (function() {
+            (function(a, b) {
+                a <<= 0;
+                a && (a[(c = "PASS", 0 >>> (b += 1))] = 0);
+            })(42, -42);
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function() {
+            b = -(a = 42),
+            void ((a <<= 0) && (a[(c = "PASS", 0 >>> (b += 1))] = 0));
+            var a, b;
+        })();
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/functions.js
+++ b/test/compress/functions.js
@@ -292,11 +292,12 @@ issue_2084: {
    }
    expect: {
        var c = 0;
-        !function(c) {
-            c = 1 + c,
+        !function() {
+            var c;
+            c = 1 + (c = -1),
            c = 1 + (c = 0),
            0 !== 23..toString() && (c = 1 + c);
-        }(-1),
+        }(),
        console.log(c);
    }
    expect_stdout: "0"
@@ -1051,11 +1052,9 @@ issue_2616: {
    }
    expect: {
        var c = "FAIL";
-        (function() {
        !function(NaN) {
            (true << NaN) - 0/0 || (c = "PASS");
        }([]);
-        })();
        console.log(c);
    }
    expect_stdout: "PASS"
@@ -1086,13 +1085,11 @@ issue_2620_1: {
    }
    expect: {
        var c = "FAIL";
-        (function() {
-            (function(a) {
+        !function(a) {
            if (function(a) {
                a && a();
            }(), a) c = "PASS";
-            })(1);
-        })(),
+        }(1),
        console.log(c);
    }
    expect_stdout: "PASS"
@@ -1160,8 +1157,7 @@ issue_2620_3: {
    }
    expect: {
        var c = "FAIL";
-        (function() {
-            (function(a, NaN) {
+        !function(a, NaN) {
            (function() {
                switch (a) {
                    case a:
@@ -1170,8 +1166,7 @@ issue_2620_3: {
                    break;
                }
            })();
-            })(NaN);
-        })();
+        }(NaN);
        console.log(c);
    }
    expect_stdout: "PASS"
@@ -1341,11 +1336,9 @@ issue_2630_4: {
    }
    expect: {
        var x = 3, a = 1, b = 2;
-        (function() {
-            (function() {
-                while (--x >= 0 && void (a++, b += a));
-            })();
-        })();
+        !function() {
+            while (--x >= 0 && void (b += ++a));
+        }();
        console.log(a);
    }
    expect_stdout: "2"
@@ -1989,3 +1982,72 @@ issue_2783: {
    }
    expect_stdout: "PASS"
 }
+
+issue_2898: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        (function() {
+            while (f());
+            function f() {
+                var b = (c = 1 + c, void (c = 1 + c));
+                b && b[0];
+            }
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        (function() {
+            while (b = void 0, void ((b = void (c = 1 + (c = 1 + c))) && b[0]));
+            var b;
+        })(),
+        console.log(c);
+    }
+    expect_stdout: "2"
+}
+
+deduplicate_parenthesis: {
+    input: {
+        ({}).a = b;
+        (({}).a = b)();
+        (function() {}).a = b;
+        ((function() {}).a = b)();
+    }
+    expect_exact: "({}).a=b;({}.a=b)();(function(){}).a=b;(function(){}.a=b)();"
+}
+
+drop_lone_use_strict: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        function f1() {
+            "use strict";
+        }
+        function f2() {
+            "use strict";
+            function f3() {
+                "use strict";
+            }
+        }
+        (function f4() {
+            "use strict";
+        })();
+    }
+    expect: {
+        function f1() {
+        }
+        function f2() {
+            "use strict";
+            function f3() {
+            }
+        }
+    }
+}
--- a/test/compress/hoist_props.js
+++ b/test/compress/hoist_props.js
@@ -239,14 +239,14 @@ name_collision_2: {
    input: {
        var o = {
            p: 1,
-            0: function(x) {
+            "+": function(x) {
                return x;
            },
-            1: function(x) {
+            "-": function(x) {
                return x + 1;
            }
        }, o__$0 = 2, o__$1 = 3;
-        console.log(o.p === o.p, o[0](4), o[1](5), o__$0, o__$1);
+        console.log(o.p === o.p, o["+"](4), o["-"](5), o__$0, o__$1);
    }
    expect: {
        var o_p = 1,
@@ -273,14 +273,14 @@ name_collision_3: {
    input: {
        var o = {
            p: 1,
-            0: function(x) {
+            "+": function(x) {
                return x;
            },
-            1: function(x) {
+            "-": function(x) {
                return x + 1;
            }
        }, o__$0 = 2, o__$1 = 3;
-        console.log(o.p === o.p, o[0](4), o[1](5));
+        console.log(o.p === o.p, o["+"](4), o["-"](5));
    }
    expect: {
        var o_p = 1,
--- a/test/compress/if_return.js
+++ b/test/compress/if_return.js
@@ -243,7 +243,7 @@ issue_1089: {
    expect: {
        function x() {
            var f = document.getElementById("fname");
-            if (f.files[0].size > 12345)
+            if (12345 < f.files[0].size)
                return alert("alert"), f.focus(), !1;
        }
    }
--- a/test/compress/issue-1704.js
+++ b/test/compress/issue-1704.js
@@ -104,7 +104,7 @@ mangle_catch_toplevel: {
        }
        console.log(a);
    }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_exact: 'var c="FAIL";try{throw 1}catch(o){c="PASS"}console.log(c);'
    expect_stdout: "PASS"
 }

@@ -148,7 +148,7 @@ mangle_catch_var_toplevel: {
        }
        console.log(a);
    }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_exact: 'var r="FAIL";try{throw 1}catch(o){var r="PASS"}console.log(r);'
    expect_stdout: "PASS"
 }

@@ -345,3 +345,95 @@ mangle_catch_redef_2_ie8_toplevel: {
    expect_exact: 'try{throw"FAIL1"}catch(o){var o="FAIL2"}console.log(o);'
    expect_stdout: "undefined"
 }
+
+mangle_catch_redef_3: {
+    mangle = {
+        ie8: false,
+        toplevel: false,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var o="PASS";try{throw 0}catch(o){(function(){function c(){o="FAIL"}c(),c()})()}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_3_toplevel: {
+    mangle = {
+        ie8: false,
+        toplevel: true,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var c="PASS";try{throw 0}catch(c){(function(){function o(){c="FAIL"}o(),o()})()}console.log(c);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_ie8_3: {
+    mangle = {
+        ie8: true,
+        toplevel: false,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var o="PASS";try{throw 0}catch(o){(function(){function c(){o="FAIL"}c(),c()})()}console.log(o);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_redef_3_ie8_toplevel: {
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        var o = "PASS";
+        try {
+            throw 0;
+        } catch (o) {
+            (function() {
+                function f() {
+                    o = "FAIL";
+                }
+                f(), f();
+            })();
+        }
+        console.log(o);
+    }
+    expect_exact: 'var c="PASS";try{throw 0}catch(c){(function(){function o(){c="FAIL"}o(),o()})()}console.log(c);'
+    expect_stdout: "PASS"
+}
--- a/test/compress/issue-1733.js
+++ b/test/compress/issue-1733.js
@@ -15,7 +15,7 @@ function_iife_catch: {
        }
        f();
    }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
    expect_stdout: "0 1"
 }

@@ -36,7 +36,7 @@ function_iife_catch_ie8: {
        }
        f();
    }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_exact: "function f(c){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
    expect_stdout: "0 1"
 }

@@ -61,7 +61,7 @@ function_catch_catch: {
        }
        f();
    }
-    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_exact: "var o=0;function f(){try{throw 1}catch(o){try{throw 2}catch(c){var c=3;console.log(c)}}console.log(c)}f();"
    expect_stdout: [
        "3",
        "undefined",
--- a/test/compress/issue-2871.js
+++ b/test/compress/issue-2871.js
@@ -0,0 +1,37 @@
+comparison_with_undefined: {
+    options = {
+        comparisons: true,
+    }
+    input: {
+        a == undefined;
+        a != undefined;
+        a === undefined;
+        a !== undefined;
+
+        undefined == a;
+        undefined != a;
+        undefined === a;
+        undefined !== a;
+
+        void 0 == a;
+        void 0 != a;
+        void 0 === a;
+        void 0 !== a;
+    }
+    expect: {
+        null == a;
+        null != a;
+        void 0 === a;
+        void 0 !== a;
+
+        null == a;
+        null != a;
+        void 0 === a;
+        void 0 !== a;
+
+        null == a;
+        null != a;
+        void 0 === a;
+        void 0 !== a;
+    }
+}
--- a/test/compress/loops.js
+++ b/test/compress/loops.js
@@ -605,3 +605,20 @@ issue_2740_5: {
    }
    expect_stdout: "0 undefined"
 }
+
+issue_2904: {
+    options = {
+        join_vars: true,
+        loops: true,
+    }
+    input: {
+        var a = 1;
+        do {
+            console.log(a);
+        } while (--a);
+    }
+    expect: {
+        for (var a = 1; console.log(a), --a;);
+    }
+    expect_stdout: "1"
+}
--- a/test/compress/properties.js
+++ b/test/compress/properties.js
@@ -1588,3 +1588,55 @@ issue_2816: {
    }
    expect_stdout: "3 2 4"
 }
+
+issue_2893_1: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var o = {
+            get a() {
+                return "PASS";
+            },
+        };
+        o.a = "FAIL";
+        console.log(o.a);
+    }
+    expect: {
+        var o = {
+            get a() {
+                return "PASS";
+            },
+        };
+        o.a = "FAIL";
+        console.log(o.a);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2893_2: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        var o = {
+            set a(v) {
+                this.b = v;
+            },
+            b: "FAIL",
+        };
+        o.a = "PASS";
+        console.log(o.b);
+    }
+    expect: {
+        var o = {
+            set a(v) {
+                this.b = v;
+            },
+            b: "FAIL",
+        };
+        o.a = "PASS";
+        console.log(o.b);
+    }
+    expect_stdout: "PASS"
+}
--- a/test/compress/pure_getters.js
+++ b/test/compress/pure_getters.js
@@ -694,3 +694,470 @@ issue_2678: {
    }
    expect_stdout: "PASS"
 }
+
+issue_2838: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+    }
+    input: {
+        function f(a, b) {
+            (a || b).c = "PASS";
+            (function() {
+                return f(a, b);
+            }).prototype.foo = "bar";
+        }
+        var o = {};
+        f(null, o);
+        console.log(o.c);
+    }
+    expect: {
+        function f(a, b) {
+            (a || b).c = "PASS";
+        }
+        var o = {};
+        f(null, o);
+        console.log(o.c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2938_1: {
+    options = {
+        pure_getters: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            a.b = "PASS";
+        }
+        var o = {};
+        f(o);
+        console.log(o.b);
+    }
+    expect: {
+        function f(a) {
+            a.b = "PASS";
+        }
+        var o = {};
+        f(o);
+        console.log(o.b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2938_2: {
+    options = {
+        pure_getters: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var Parser = function Parser() {};
+        var p = Parser.prototype;
+        p.initialContext = function initialContext() {
+            console.log("PASS");
+        };
+        p.braceIsBlock = function() {};
+        (new Parser).initialContext();
+    }
+    expect: {
+        var Parser = function() {};
+        var p = Parser.prototype;
+        p.initialContext = function() {
+            console.log("PASS");
+        };
+        p.braceIsBlock = function() {};
+        (new Parser).initialContext();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2938_3: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        function f(a) {
+            var unused = a.a;
+            a.b = "PASS";
+            a.c;
+        }
+        var o = {};
+        o.d;
+        f(o);
+        console.log(o.b);
+    }
+    expect: {
+        function f(a) {
+            a.b = "PASS";
+        }
+        var o = {};
+        f(o);
+        console.log(o.b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2938_4: {
+    options = {
+        pure_getters: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var Parser = function Parser() {};
+        var p = Parser.prototype;
+        var unused = p.x;
+        p.initialContext = function initialContext() {
+            p.y;
+            console.log("PASS");
+        };
+        p.braceIsBlock = function() {};
+        (new Parser).initialContext();
+    }
+    expect: {
+        var Parser = function() {};
+        var p = Parser.prototype;
+        p.initialContext = function() {
+            console.log("PASS");
+        };
+        p.braceIsBlock = function() {};
+        (new Parser).initialContext();
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_vars_1_true: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+    expect: {
+        function f(a, b) {
+            for (;;) {
+                if (a.g() || b.p) break;
+            }
+        }
+    }
+}
+
+collapse_vars_1_false: {
+    options = {
+        collapse_vars: true,
+        pure_getters: false,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+    expect: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+}
+
+collapse_vars_1_strict: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+    expect: {
+        function f(a, b) {
+            for (;;) {
+                var c = a.g();
+                var d = b.p;
+                if (c || d) break;
+            }
+        }
+    }
+}
+
+collapse_vars_2_true: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            g.b = g.a = function() {};
+            return g;
+        }
+    }
+}
+
+collapse_vars_2_false: {
+    options = {
+        collapse_vars: true,
+        pure_getters: false,
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+}
+
+collapse_vars_2_strict: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            g.a = function() {};
+            g.b = g.a;
+            return g;
+        }
+    }
+    expect: {
+        function f() {
+            function g() {}
+            g.b = g.a = function() {};
+            return g;
+        }
+    }
+}
+
+collapse_rhs_true: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        console.log((42..length = "PASS", "PASS"));
+        console.log(("foo".length = "PASS", "PASS"));
+        console.log((false.length = "PASS", "PASS"));
+        console.log((function() {}.length = "PASS", "PASS"));
+        console.log(({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS", "PASS"));
+    }
+    expect: {
+        console.log(42..length = "PASS");
+        console.log("foo".length = "PASS");
+        console.log(false.length = "PASS");
+        console.log(function() {}.length = "PASS");
+        console.log({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+collapse_rhs_false: {
+    options = {
+        collapse_vars: true,
+        pure_getters: false,
+    }
+    input: {
+        console.log((42..length = "PASS", "PASS"));
+        console.log(("foo".length = "PASS", "PASS"));
+        console.log((false.length = "PASS", "PASS"));
+        console.log((function() {}.length = "PASS", "PASS"));
+        console.log(({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS", "PASS"));
+    }
+    expect: {
+        console.log(42..length = "PASS");
+        console.log("foo".length = "PASS");
+        console.log(false.length = "PASS");
+        console.log(function() {}.length = "PASS");
+        console.log({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+collapse_rhs_strict: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        console.log((42..length = "PASS", "PASS"));
+        console.log(("foo".length = "PASS", "PASS"));
+        console.log((false.length = "PASS", "PASS"));
+        console.log((function() {}.length = "PASS", "PASS"));
+        console.log(({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS", "PASS"));
+    }
+    expect: {
+        console.log(42..length = "PASS");
+        console.log("foo".length = "PASS");
+        console.log(false.length = "PASS");
+        console.log(function() {}.length = "PASS");
+        console.log({
+            get length() {
+                return "FAIL";
+            }
+        }.length = "PASS");
+    }
+    expect_stdout: [
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+        "PASS",
+    ]
+}
+
+collapse_rhs_setter: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+    }
+    input: {
+        try {
+            console.log(({
+                set length(v) {
+                    throw "PASS";
+                }
+            }.length = "FAIL", "FAIL"));
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect: {
+        try {
+            console.log({
+                set length(v) {
+                    throw "PASS";
+                }
+            }.length = "FAIL");
+        } catch (e) {
+            console.log(e);
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_rhs_call: {
+    options = {
+        collapse_vars: true,
+        passes: 2,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var o = {};
+        function f() {
+            console.log("PASS");
+        }
+        o.f = f;
+        f();
+    }
+    expect: {
+        ({}.f = function() {
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+collapse_rhs_lhs: {
+    options = {
+        collapse_vars: true,
+        pure_getters: true,
+    }
+    input: {
+        function f(a, b) {
+            a.b = b, b += 2;
+            console.log(a.b, b);
+        }
+        f({}, 1);
+    }
+    expect: {
+        function f(a, b) {
+            a.b = b, b += 2;
+            console.log(a.b, b);
+        }
+        f({}, 1);
+    }
+    expect_stdout: "1 3"
+}
--- a/test/compress/reduce_vars.js
+++ b/test/compress/reduce_vars.js
@@ -76,14 +76,12 @@ modified: {
            console.log(a + 1);
            console.log(b + 1);
        }
-
        function f1() {
            var a = 1, b = 2;
            --b;
            console.log(a + 1);
            console.log(b + 1);
        }
-
        function f2() {
            var a = 1, b = 2, c = 3;
            b = c;
@@ -92,7 +90,6 @@ modified: {
            console.log(a + c);
            console.log(a + b + c);
        }
-
        function f3() {
            var a = 1, b = 2, c = 3;
            b *= c;
@@ -101,7 +98,6 @@ modified: {
            console.log(a + c);
            console.log(a + b + c);
        }
-
        function f4() {
            var a = 1, b = 2, c = 3;
            if (a) {
@@ -114,28 +110,26 @@ modified: {
            console.log(a + c);
            console.log(a + b + c);
        }
-
        function f5(a) {
            B = a;
-            console.log(A ? 'yes' : 'no');
-            console.log(B ? 'yes' : 'no');
+            console.log(typeof A ? "yes" : "no");
+            console.log(typeof B ? "yes" : "no");
        }
+        f0(), f1(), f2(), f3(), f4(), f5();
    }
    expect: {
        function f0() {
            var b = 2;
            b++;
            console.log(2);
-            console.log(b + 1);
+            console.log(4);
        }
-
        function f1() {
            var b = 2;
            --b;
            console.log(2);
-            console.log(b + 1);
+            console.log(2);
        }
-
        function f2() {
            3;
            console.log(4);
@@ -143,16 +137,14 @@ modified: {
            console.log(4);
            console.log(7);
        }
-
        function f3() {
            var b = 2;
            b *= 3;
-            console.log(1 + b);
-            console.log(b + 3);
+            console.log(7);
+            console.log(9);
            console.log(4);
-            console.log(1 + b + 3);
+            console.log(10);
        }
-
        function f4() {
            var b = 2, c = 3;
            b = c;
@@ -161,13 +153,33 @@ modified: {
            console.log(1 + c);
            console.log(1 + b + c);
        }
-
        function f5(a) {
            B = a;
-            console.log(A ? 'yes' : 'no');
-            console.log(B ? 'yes' : 'no');
+            console.log(typeof A ? "yes" : "no");
+            console.log(typeof B ? "yes" : "no");
        }
+        f0(), f1(), f2(), f3(), f4(), f5();
    }
+    expect_stdout: [
+        "2",
+        "4",
+        "2",
+        "2",
+        "4",
+        "6",
+        "4",
+        "7",
+        "7",
+        "9",
+        "4",
+        "10",
+        "4",
+        "6",
+        "4",
+        "7",
+        "yes",
+        "yes",
+    ]
 }

 unsafe_evaluate: {
@@ -745,7 +757,7 @@ iife: {
    expect: {
        !function(a, b, c) {
            b++;
-            console.log(0, 1 * b, 5);
+            console.log(0, 3, 5);
        }(1, 2, 3);
    }
    expect_stdout: true
@@ -766,7 +778,7 @@ iife_new: {
    expect: {
        var A = new function(a, b, c) {
            b++;
-            console.log(0, 1 * b, 5);
+            console.log(0, 3, 5);
        }(1, 2, 3);
    }
    expect_stdout: true
@@ -1166,9 +1178,7 @@ toplevel_on_loops_1: {
            console.log("bar:", --x);
        }
        var x = 3;
-        do
-            bar();
-        while (x);
+        for (;bar(), x;);
    }
    expect_stdout: true
 }
@@ -1196,9 +1206,7 @@ toplevel_off_loops_1: {
            console.log("bar:", --x);
        }
        var x = 3;
-        do
-            bar();
-        while (x);
+        for (;bar(), x;);
    }
    expect_stdout: true
 }
@@ -1253,9 +1261,7 @@ toplevel_off_loops_2: {
            console.log("bar:");
        }
        var x = 3;
-        do
-            bar();
-        while (x);
+        for (;bar(), x;);
    }
 }

@@ -5360,3 +5366,182 @@ issue_2799_2: {
    }
    expect_stdout: "PASS"
 }
+
+issue_2836: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return "FAIL";
+        }
+        console.log(f());
+        function f() {
+            return "PASS";
+        }
+    }
+    expect: {
+        console.log(function() {
+            return "PASS";
+        }());
+    }
+    expect_stdout: "PASS"
+}
+
+lvalues_def_1: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        var a = b++, b = NaN;
+        console.log(a, b);
+    }
+    expect: {
+        var b = 1;
+        var a = b++;
+        b = NaN;
+        console.log(a, b);
+    }
+    expect_stdout: "1 NaN"
+}
+
+lvalues_def_2: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        var a = b += 1, b = NaN;
+        console.log(a, b);
+    }
+    expect: {
+        var b = 1;
+        var a = b += 1;
+        b = NaN;
+        console.log(a, b);
+    }
+    expect_stdout: "2 NaN"
+}
+
+chained_assignments: {
+    options = {
+        evaluate: true,
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            var a = [0x5e, 0xad, 0xbe, 0xef];
+            var b = 0;
+            b |= a[0];
+            b <<= 8;
+            b |= a[1];
+            b <<= 8;
+            b |= a[2];
+            b <<= 8;
+            b |= a[3];
+            return b;
+        }
+        console.log(f().toString(16));
+    }
+    expect: {
+        console.log("5eadbeef");
+    }
+    expect_stdout: "5eadbeef"
+}
+
+issue_2860_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a ^= 1;
+            a ^= 2;
+        }());
+    }
+    expect: {
+        console.log(function(a) {
+            return 1 ^ a;
+        }());
+    }
+    expect_stdout: "1"
+}
+
+issue_2860_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        reduce_vars: true,
+    }
+    input: {
+        console.log(function(a) {
+            return a ^= 1;
+            a ^= 2;
+        }());
+    }
+    expect: {
+        console.log(1);
+    }
+    expect_stdout: "1"
+}
+
+issue_2869: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+    }
+    input: {
+        var c = "FAIL";
+        (function f(a) {
+            var a;
+            if (!f) a = 0;
+            if (a) c = "PASS";
+        })(1);
+        console.log(c);
+    }
+    expect: {
+        var c = "FAIL";
+        (function f(a) {
+            var a;
+            if (!f) a = 0;
+            if (a) c = "PASS";
+        })(1);
+        console.log(c);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2919: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var arr = [ function() {} ];
+        console.log(typeof arr[0]);
+    }
+    expect: {
+        console.log("function");
+    }
+    expect_stdout: "function"
+}
--- a/test/compress/rename.js
+++ b/test/compress/rename.js
@@ -109,7 +109,7 @@ mangle_catch_toplevel: {
        }
        console.log(a);
    }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(c){o="PASS"}console.log(o);'
+    expect_exact: 'var c="FAIL";try{throw 1}catch(o){c="PASS"}console.log(c);'
    expect_stdout: "PASS"
 }

@@ -155,7 +155,7 @@ mangle_catch_var_toplevel: {
        }
        console.log(a);
    }
-    expect_exact: 'var o="FAIL";try{throw 1}catch(r){var o="PASS"}console.log(o);'
+    expect_exact: 'var r="FAIL";try{throw 1}catch(o){var r="PASS"}console.log(r);'
    expect_stdout: "PASS"
 }

@@ -451,7 +451,7 @@ function_iife_catch: {
        }
        f();
    }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
    expect_stdout: "0 1"
 }

@@ -473,7 +473,7 @@ function_iife_catch_ie8: {
        }
        f();
    }
-    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_exact: "function f(c){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
    expect_stdout: "0 1"
 }

@@ -499,7 +499,7 @@ function_catch_catch: {
        }
        f();
    }
-    expect_exact: "var o=0;function f(){try{throw 1}catch(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_exact: "var o=0;function f(){try{throw 1}catch(o){try{throw 2}catch(c){var c=3;console.log(c)}}console.log(c)}f();"
    expect_stdout: [
        "3",
        "undefined",
--- a/test/compress/screw-ie8.js
+++ b/test/compress/screw-ie8.js
@@ -102,12 +102,12 @@ dont_screw_try_catch: {
        };
    }
    expect: {
-        bad = function(n){
-            return function(t){
+        bad = function(t){
+            return function(n){
                try{
-                    n()
-                } catch(n) {
-                    t(n)
+                    t()
+                } catch(t) {
+                    n(t)
                }
            }
        };
@@ -349,11 +349,11 @@ issue_2254_1: {
        try {
            console.log(f("PASS"));
        } catch (e) {}
-        function f(e) {
+        function f(t) {
            try {
                throw "FAIL";
-            } catch (t) {
-                return e;
+            } catch (e) {
+                return t;
            }
        }
    }
--- a/test/compress/sequences.js
+++ b/test/compress/sequences.js
@@ -668,8 +668,7 @@ side_effects_cascade_2: {
    }
    expect: {
        function f(a, b) {
-            b = a,
-            !a + (b += a) || (b += a),
+            !(b = a) + (b += a) || (b += a),
            b = a;
        }
    }
--- a/test/compress/transform.js
+++ b/test/compress/transform.js
@@ -104,6 +104,7 @@ if_return: {
        conditionals: true,
        if_return: true,
        sequences: true,
+        side_effects: true,
    }
    input: {
        function f(w, x, y, z) {
@@ -124,7 +125,7 @@ if_return: {
                if (w) {
                    if (y) return;
                } else if (z) return;
-                return x == y || (x && w(), y && z(), !0);
+                return x == y || (x && w(), y && z()), !0;
            }
        }
    }
--- a/test/mocha/minify.js
+++ b/test/mocha/minify.js
@@ -46,10 +46,10 @@ describe("minify", function() {
        assert.strictEqual(compressed, [
            "function n(n){return 3*n}",
            "function r(n){return n/2}",
-            "var o=console.log.bind(console);",
-            'function c(n){o("Foo:",2*n)}',
+            "var c=console.log.bind(console);",
+            'function o(o){c("Foo:",2*o)}',
            "var a=n(3),b=r(12);",
-            'o("qux",a,b),c(11);',
+            'c("qux",a,b),o(11);',
        ].join(""));
        assert.strictEqual(run_code(compressed), run_code(original));
    });
@@ -79,10 +79,10 @@ describe("minify", function() {
        assert.strictEqual(compressed, [
            "function n(n){return 3*n}",
            "function r(n){return n/2}",
-            "var o=console.log.bind(console);",
-            'function c(n){o("Foo:",2*n)}',
+            "var c=console.log.bind(console);",
+            'function o(o){c("Foo:",2*o)}',
            "var a=n(3),b=r(12);",
-            'o("qux",a,b),c(11);',
+            'c("qux",a,b),o(11);',
        ].join(""));
        assert.strictEqual(run_code(compressed), run_code(original));
    });
@@ -226,7 +226,7 @@ describe("minify", function() {
                        content: "inline"
                    }
                });
-                assert.strictEqual(result.code, "var bar=function(){return function(bar){return bar}}();");
+                assert.strictEqual(result.code, "var bar=function(bar){return bar};");
                assert.strictEqual(warnings.length, 1);
                assert.strictEqual(warnings[0], "inline source map not found");
            } finally {
--- a/test/run-tests.js
+++ b/test/run-tests.js
@@ -135,7 +135,6 @@ function run_compress_tests() {
            var output = cmp.compress(input);
            output.figure_out_scope(test.mangle);
            if (test.mangle) {
-                U.base54.reset();
                output.compute_char_frequency(test.mangle);
                output.mangle_names(test.mangle);
                if (test.mangle.properties) {
@@ -183,7 +182,7 @@ function run_compress_tests() {
            }
            if (test.expect_stdout
                && (!test.node_version || semver.satisfies(process.version, test.node_version))) {
-                var stdout = sandbox.run_code(input_code);
+                var stdout = sandbox.run_code(input_code, true);
                if (test.expect_stdout === true) {
                    test.expect_stdout = stdout;
                }
@@ -197,7 +196,7 @@ function run_compress_tests() {
                    });
                    return false;
                }
-                stdout = sandbox.run_code(output);
+                stdout = sandbox.run_code(output, true);
                if (!sandbox.same_stdout(test.expect_stdout, stdout)) {
                    log("!!! failed\n---INPUT---\n{input}\n---EXPECTED {expected_type}---\n{expected}\n---ACTUAL {actual_type}---\n{actual}\n\n", {
                        input: input_formatted,
@@ -372,13 +371,14 @@ function reminify(orig_options, input_code, input_formatted, expect_stdout) {
        var options_formatted = JSON.stringify(options, null, 4);
        var result = U.minify(input_code, options);
        if (result.error) {
-            log("!!! failed input reminify\n---INPUT---\n{input}\n--ERROR---\n{error}\n\n", {
+            log("!!! failed input reminify\n---INPUT---\n{input}\n---OPTIONS---\n{options}\n--ERROR---\n{error}\n\n", {
                input: input_formatted,
+                options: options_formatted,
                error: result.error,
            });
            return false;
        } else {
-            var stdout = sandbox.run_code(result.code);
+            var stdout = sandbox.run_code(result.code, true);
            if (typeof expect_stdout != "string" && typeof stdout != "string" && expect_stdout.name == stdout.name) {
                stdout = expect_stdout;
            }
--- a/test/sandbox.js
+++ b/test/sandbox.js
@@ -1,6 +1,27 @@
 var semver = require("semver");
 var vm = require("vm");

+function createContext() {
+    var context = Object.create(null);
+    Object.defineProperty(context, "console", {
+        value: function() {
+            var con = Object.create(null);
+            Object.defineProperty(con, "log", {
+                value: function(msg) {
+                    if (arguments.length == 1 && typeof msg == "string") {
+                        return console.log("%s", msg);
+                    }
+                    return console.log.apply(console, [].map.call(arguments, function(arg) {
+                        return safe_log(arg, 3);
+                    }));
+                }
+            });
+            return con;
+        }()
+    });
+    return vm.createContext(context);
+}
+
 function safe_log(arg, level) {
    if (arg) switch (typeof arg) {
      case "function":
@@ -9,7 +30,8 @@ function safe_log(arg, level) {
        if (/Error$/.test(arg.name)) return arg.toString();
        arg.constructor.toString();
        if (level--) for (var key in arg) {
-            if (!Object.getOwnPropertyDescriptor(arg, key).get) {
+            var desc = Object.getOwnPropertyDescriptor(arg, key);
+            if (!desc || !desc.get) {
                arg[key] = safe_log(arg[key], level);
            }
        }
@@ -21,16 +43,16 @@ function strip_func_ids(text) {
    return text.toString().replace(/F[0-9]{6}N/g, "<F<>N>");
 }

+var context;
 var FUNC_TOSTRING = [
    "[ Array, Boolean, Error, Function, Number, Object, RegExp, String].forEach(function(f) {",
    "    f.toString = Function.prototype.toString;",
-    "    f.valueOf = Function.prototype.valueOf;",
    "});",
-    "Function.prototype.toString = Function.prototype.valueOf = function() {",
+    "Function.prototype.toString = function() {",
    "    var id = 100000;",
    "    return function() {",
    "        var n = this.name;",
-    '        if (!/^F[0-9]{6}N$/.test(n)) {',
+    "        if (!/^F[0-9]{6}N$/.test(n)) {",
    '            n = "F" + ++id + "N";',
 ].concat(Object.getOwnPropertyDescriptor(Function.prototype, "name").configurable ? [
    '            Object.defineProperty(this, "name", {',
@@ -40,40 +62,34 @@ var FUNC_TOSTRING = [
    "            });",
 ] : [], [
    "        }",
-    '        return "[Function: " + n + "]";',
-    "    }",
+    '        return "function(){}";',
+    "    };",
    "}();",
-    'Object.defineProperty(Function.prototype, "valueOf", { enumerable: false });',
 ]).join("\n");
-exports.run_code = function(code) {
+exports.run_code = function(code, reuse) {
    var stdout = "";
    var original_write = process.stdout.write;
    process.stdout.write = function(chunk) {
        stdout += chunk;
    };
    try {
-        vm.runInNewContext([
+        if (!reuse || !context) context = createContext();
+        vm.runInContext([
            FUNC_TOSTRING,
            "!function() {",
            code,
            "}();",
-        ].join("\n"), {
-            console: {
-                log: function(msg) {
-                    if (arguments.length == 1 && typeof msg == "string") {
-                        return console.log("%s", msg);
-                    }
-                    return console.log.apply(console, [].map.call(arguments, function(arg) {
-                        return safe_log(arg, 3);
-                    }));
-                }
-            }
-        }, { timeout: 5000 });
+        ].join("\n"), context, { timeout: 5000 });
        return stdout;
    } catch (ex) {
        return ex;
    } finally {
        process.stdout.write = original_write;
+        if (!reuse || /prototype/.test(code)) {
+            context = null;
+        } else for (var key in context) {
+            delete context[key];
+        }
    }
 };
 exports.same_stdout = semver.satisfies(process.version, "0.12") ? function(expected, actual) {
--- a/test/ufuzz.js
+++ b/test/ufuzz.js
@@ -1024,7 +1024,6 @@ function log_suspects(minify_options, component) {
 }

 function log_rename(options) {
-    if (!options.rename) return;
    var m = JSON.parse(JSON.stringify(options));
    m.rename = false;
    var result = UglifyJS.minify(original_code, m);
Author	SHA1	Message	Date
Alex Lam S.L	951d87ca94	v3.3.13	2018-03-04 07:38:49 +00:00
Alex Lam S.L	798fc21530	improve `test/run-test.js` performance (#2971 ) - allow reuse of contextified sandbox - minimise bottleneck from `vm.createContext()`	2018-03-04 04:50:00 +08:00
Alex Lam S.L	a75a046abb	compress `arguments[index]` (#2967 ) - always replace with existing parameter - only introduce new parameter if `keep_fargs` is disabled	2018-03-02 11:22:09 +08:00
Alex Lam S.L	38f2b4579f	fix value reference caching in `evaluate` (#2969 ) fixes #2968	2018-03-02 04:04:29 +08:00
Alex Lam S.L	56e2a369d0	enhance `conditionals` (#2966 ) - `x ? (y, w) : (z, w)` => `x ? y : z, w`	2018-02-28 23:34:48 +08:00
Alex Lam S.L	0daa199fa8	migrate safe transformations out of `unsafe_comps` (#2962 ) fixes #2959	2018-02-28 22:02:24 +08:00
Alex Lam S.L	73e98dcda4	drop `side_effects`-free `return` values (#2965 )	2018-02-28 19:59:19 +08:00
Alex Lam S.L	36bca6934d	enhance `collapse_vars` (#2952 ) - `a = b, b` => `a = b` - `a.b = c, c()` => `(a.b = c)()`	2018-02-28 15:19:32 +08:00
Alex Lam S.L	ace5811691	drop lone "use strict" in function body (#2963 ) fixes #2961	2018-02-26 15:22:52 +08:00
Dan	ba7bad0dbd	show benchmark subtotal (#2960 ) At the end of the benchmark, sums of the input, output and gzip values are shown, such as: Subtotal Original: 7785102 bytes Uglified: 2283862 bytes GZipped: 662354 bytes	2018-02-26 11:46:26 +08:00
Alex Lam S.L	b8b2ac5230	improve fix for #2954 (#2958 )	2018-02-26 03:14:22 +08:00
Alex Lam S.L	ea2359381b	fix `collapse_vars` on nested exception (#2955 ) fixes #2954	2018-02-25 15:39:00 +08:00
Alex Lam S.L	52de64cf16	deduplicate parenthesis around object and function literals (#2953 )	2018-02-25 02:14:33 +08:00
Alex Lam S.L	455790202a	minor clean-ups (#2951 )	2018-02-24 02:24:47 +08:00
Alex Lam S.L	f40f5eb228	improve `mangle` (#2948 )	2018-02-23 23:51:49 +08:00
Alex Lam S.L	604caa09e7	v3.3.12	2018-02-22 08:14:29 +00:00
Alex Lam S.L	29a71d3aae	more tests for #2938 (#2940 )	2018-02-21 04:19:42 +08:00
Alex Lam S.L	39a907bde3	workaround `pure_getters=true` when dropping unused assignments (#2939 ) fixes #2938	2018-02-20 17:38:40 +08:00
Alex Lam S.L	70474310f3	improve `unsafe` `evaluate` of `function` (#2936 ) Miscellaneous - simplify `run_code()` hack	2018-02-19 18:47:02 +08:00
Alex Lam S.L	b5f0f4f3a1	reduce false positives from object literals (#2935 )	2018-02-19 06:21:07 +08:00
Alex Lam S.L	2905fd625a	reduce false positives from labels (#2934 )	2018-02-19 03:55:33 +08:00
Alex Lam S.L	4facd94029	reduce false positives from noop (#2933 )	2018-02-19 01:15:05 +08:00
Alex Lam S.L	4b5993ff15	fix crash in `may_throw()` (#2932 ) fixes #2931	2018-02-18 21:51:27 +08:00
Alex Lam S.L	2351a672ea	fix `dead_code` on exceptional `return` (#2930 ) fixes #2929	2018-02-18 04:36:00 +08:00
Alex Lam S.L	4a528c469c	reduce false positives from `function.toString()` (#2928 )	2018-02-18 02:13:26 +08:00
Alex Lam S.L	82d1ef0242	fix `unsafe` `evaluate` of `function` property (#2927 ) fixes #2926	2018-02-17 21:33:36 +08:00
Alex Lam S.L	7fdd2082a6	drop unused "class" definition IIFEs (#2923 ) fixes #805	2018-02-17 05:11:31 +08:00
Alex Lam S.L	e529f54e90	reduce `function`-related false positives (#2925 )	2018-02-17 04:35:03 +08:00
Alex Lam S.L	d626e9bf19	improve `inline` efficiency (#2924 )	2018-02-17 02:37:13 +08:00
Alex Lam S.L	a2a9459684	fix `unsafe` `evaluate` of `AST_Function` (#2920 ) fixes #2919	2018-02-16 17:21:46 +08:00
Alex Lam S.L	a3dfeea144	v3.3.11	2018-02-15 19:24:35 +00:00
Alex Lam S.L	d316fb139d	fix `unsafe` `evaluate` on type-converting operators (#2917 ) fixes #2916	2018-02-14 16:48:47 +08:00
Alex Lam S.L	83d8aa8b12	fix `collapse_vars` within loops (#2915 ) fixes #2914	2018-02-14 05:15:52 +08:00
Alex Lam S.L	4f1c12b6fd	report options upon reminify input error (#2911 )	2018-02-13 07:29:39 +08:00
Alex Lam S.L	d8e0e34354	collapse within unary expressions (#2910 )	2018-02-13 07:10:37 +08:00
Alex Lam S.L	0c4f315c02	fix corner case in `collapse_vars` (#2909 ) fixes #2908	2018-02-13 01:41:22 +08:00
Alex Lam S.L	0809699bdc	simplify `do-while` into `for` (#2907 ) fixes #2904	2018-02-12 23:28:28 +08:00
Alex Lam S.L	2088e1c19d	fix AST corruption due to `collapse_vars` & `inline` (#2899 ) fixes #2898	2018-02-09 06:54:37 +08:00
Alex Lam S.L	bf1d47180c	fix `join_vars` on property accessors (#2895 ) fixes #2893	2018-02-09 01:52:39 +08:00
Alex Lam S.L	0cfbd79aa1	v3.3.10	2018-02-08 10:16:16 +00:00
Alex Lam S.L	d66d86f20b	account for exceptions in `AST_Assign.left` (#2892 ) fixes #2891	2018-02-08 03:31:51 +08:00
Alex Lam S.L	905325d3e2	update dependencies (#2889 ) acorn 5.4.1 commander 2.14.1 semver 5.5.0	2018-02-07 18:13:18 +08:00
Alex Lam S.L	dea0cc0662	mention file encoding (#2887 )	2018-02-06 16:48:49 +08:00
Alex Lam S.L	d69d8007d6	evaluate `to{Low,Upp}erCase()` under `unsafe` (#2886 )	2018-02-06 15:57:15 +08:00
Dan	c0b8f2a16d	add information on testing and code style (#2885 ) fixes #2884	2018-02-06 14:19:28 +08:00
Dan	cb0257dbbf	describe a few compiler assumptions (#2883 )	2018-02-06 14:19:03 +08:00
Dan	9637f51b68	change `undefined == x` to `null == x` (#2882 ) fixes #2871	2018-02-05 15:00:23 +08:00
Alex Lam S.L	3026bd8975	improve exceptional flow compression by `collapse_vars` (#2880 )	2018-02-04 04:18:22 +08:00
Alex Lam S.L	78a44d5ab0	maintain order between side-effects and externally observable assignments (#2879 ) fixes #2878	2018-02-04 03:58:49 +08:00
Alex Lam S.L	7e13c0db40	handle `break` & `continue` in `collapse_vars` (#2875 ) fixes #2873	2018-02-03 07:58:43 +08:00
Alex Lam S.L	e6a2e9e4d0	allow `collapse_vars` across conditional branches (#2867 )	2018-02-03 02:44:40 +08:00
Alex Lam S.L	e773f03927	fix assignment logic in `reduce_vars` (#2872 ) fixes #2869	2018-02-03 01:33:09 +08:00
Alex Lam S.L	b16380d669	fix missing corner case in #2855 (#2868 )	2018-02-02 18:08:56 +08:00
Ryan Gunn	334b07a3db	Update License Copyright Year to 2018 (#2866 )	2018-02-02 16:30:01 +08:00
Alex Lam S.L	3cc1527f00	always test for `rename` (#2865 )	2018-02-01 21:42:55 +08:00
Alex Lam S.L	525a61fb55	better fix for #2858 (#2864 )	2018-02-01 20:06:36 +08:00
Alex Lam S.L	c3a002ff97	account for side-effects in `comparisons` of `null` & `undefined` (#2863 )	2018-02-01 19:15:17 +08:00
Alex Lam S.L	fad6766a90	simplify comparisons with `undefined` & `null` (#2862 ) fixes #2857	2018-02-01 16:50:54 +08:00
Alex Lam S.L	aa664dea0a	avoid `evaluate` of compound assignment after `dead_code` transform (#2861 ) fixes #2860	2018-02-01 16:18:29 +08:00
Alex Lam S.L	102f994b9d	account for declaration assignment in `collapse_vars` (#2859 ) fixes #2858	2018-02-01 15:09:53 +08:00
Alex Lam S.L	2a4c68be4f	relax `collapse_vars` on `AST_Exit` (#2855 ) First introduced in #1862 to stop assignments to migrate beyond `return` or `throw`. Since then `collapse_vars` has been improved to handle various side-effect-related corner cases.	2018-01-31 23:49:59 +08:00
Alex Lam S.L	541e6011af	improve symbol replacement heuristic (#2851 )	2018-01-29 17:41:15 +08:00
Alex Lam S.L	6fa3fbeae8	compress chained compound assignments (#2850 )	2018-01-29 15:13:25 +08:00
Alex Lam S.L	4eb4cb656c	v3.3.9	2018-01-27 12:56:34 +00:00
Alex Lam S.L	193612ac67	fix accounting after conversion to assignment (#2847 ) Missing reference to `AST_SymbolRef` created by `unused` causes `collapse_vars` to misbehave. fixes #2846	2018-01-26 14:21:11 +08:00
Alex Lam S.L	95cfce68ea	backport of #2835 (#2841 )	2018-01-23 05:45:45 +08:00
Alex Lam S.L	ec4202590d	drop assignments to constant expressions only (#2839 ) fixes #2838	2018-01-23 02:49:54 +08:00
Alex Lam S.L	5e2cd07d6f	handle duplicate function declarations correctly (#2837 ) fixes #2836	2018-01-23 01:28:09 +08:00