fix if_return on block-scoped variables (#2021)

fixes #1317

.gitattributes

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

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,20 @@
+**Bug report or feature request?** 
+
+<!-- Note: sub-optimal but correct code is not a bug -->
+
+**ES5 or ES6+ input?** 
+
+<!-- Note: for ES6 see: https://github.com/mishoo/UglifyJS2/tree/harmony#harmony -->
+
+**Uglify version (`uglifyjs -V`)**
+
+**JavaScript input**  <!-- ideally as small as possible -->
+
+**The `uglifyjs` CLI command executed or `minify()` options used.**
+
+**JavaScript output or error produced.**
+
+<!--
+    Note: `uglify-js` only supports ES5. 
+    Those wishing to minify ES6 should use `uglify-es`.
+-->

.gitignore

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

.travis.yml

@@ -0,0 +1,11 @@
+language: node_js
+node_js:
+    - "0.10"
+    - "0.12"
+    - "4"
+    - "6"
+env:
+    - UGLIFYJS_TEST_ALL=1
+matrix:
+  fast_finish: true
+sudo: false

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/uglifyjs

@@ -3,396 +3,402 @@
 
 "use strict";
 
-var UglifyJS = require("../tools/node");
-var sys = require("util");
-var optimist = require("optimist");
-var fs = require("fs");
-var async = require("async");
-var acorn;
-var ARGS = optimist
-    .usage("$0 input1.js [input2.js ...] [options]\n\
-Use a single dash to read input from the standard input.\
-\n\n\
-NOTE: by default there is no mangling/compression.\n\
-Without [options] it will simply parse input files and dump the AST\n\
-with whitespace and comments discarded.  To achieve compression and\n\
-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("in-source-map", "Input source map, useful if you're compressing JS that was generated from some other original code.")
-    .describe("screw-ie8", "Pass this flag if you don't care about full compliance with Internet Explorer 6-8 quirks (by default UglifyJS will try to be IE-proof).")
-    .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.")
-    .describe("o", "Output file (default STDOUT).")
-    .describe("b", "Beautify output/specify output options.")
-    .describe("m", "Mangle names/pass mangler options.")
-    .describe("r", "Reserved names to exclude from mangling.")
-    .describe("c", "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.")
-    .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\
-\
-Note that currently not *all* comments can be kept when compression is on, \
-because of dead code removal or cascading statements into sequences.")
-
-    .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("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.")
-
-    .alias("p", "prefix")
-    .alias("o", "output")
-    .alias("v", "verbose")
-    .alias("b", "beautify")
-    .alias("m", "mangle")
-    .alias("c", "compress")
-    .alias("d", "define")
-    .alias("r", "reserved")
-    .alias("V", "version")
-    .alias("e", "enclose")
-
-    .string("source-map")
-    .string("source-map-root")
-    .string("source-map-url")
-    .string("b")
-    .string("m")
-    .string("c")
-    .string("d")
-    .string("e")
-    .string("comments")
-    .string("wrap")
-    .boolean("screw-ie8")
-    .boolean("export-all")
-    .boolean("self")
-    .boolean("v")
-    .boolean("stats")
-    .boolean("acorn")
-    .boolean("spidermonkey")
-    .boolean("lint")
-    .boolean("V")
-
-    .wrap(80)
-
-    .argv
-;
-
-normalize(ARGS);
-
-if (ARGS.version || ARGS.V) {
-    var json = require("../package.json");
-    sys.puts(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));
-    process.exit(0);
-}
-
-if (ARGS.h || ARGS.help) {
-    sys.puts(optimist.help());
-    process.exit(0);
-}
-
-if (ARGS.acorn) {
-    acorn = require("acorn");
-}
-
-var COMPRESS = getOptions("c", true);
-var MANGLE = getOptions("m", true);
-var BEAUTIFY = getOptions("b", true);
-
-if (ARGS.d) {
-    if (COMPRESS) COMPRESS.global_defs = getOptions("d");
-}
-
-if (ARGS.screw_ie8) {
-    if (COMPRESS) COMPRESS.screw_ie8 = true;
-    if (MANGLE) MANGLE.screw_ie8 = true;
-}
-
-if (ARGS.r) {
-    if (MANGLE) MANGLE.except = ARGS.r.replace(/^\s+|\s+$/g).split(/\s*,+\s*/);
-}
-
-var OUTPUT_OPTIONS = {
-    beautify: BEAUTIFY ? true : false
-};
-
-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);
-            }
-        }
-    }
-}
-
-var files = ARGS._.slice();
-
-if (ARGS.self) {
-    if (files.length > 0) {
-        sys.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) {
-    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);
-        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));
-        process.exit(1);
-    }
-}
-
-async.eachLimit(files, 1, function (file, cb) {
-    read_whole_file(file, function (err, code) {
-        if (err) {
-            sys.error("ERROR: can't read file: " + filename);
-            process.exit(1);
-        }
-        if (ARGS.p != null) {
-            file = file.replace(/^\/+/, "").split(/\/+/).slice(ARGS.p).join("/");
-        }
-        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
-                });
-            };
-        });
-        cb();
-    });
-}, function () {
-    if (ARGS.acorn || ARGS.spidermonkey) time_it("convert_ast", function(){
-        TOPLEVEL = UglifyJS.AST_Node.from_mozilla_ast(TOPLEVEL);
-    });
-
-    if (ARGS.wrap) {
-        TOPLEVEL = TOPLEVEL.wrap_commonjs(ARGS.wrap, ARGS.export_all);
-    }
-
-    if (ARGS.enclose) {
-        var arg_parameter_list = ARGS.enclose;
-
-        if (!(arg_parameter_list instanceof Array)) {
-            arg_parameter_list = [arg_parameter_list];
-        }
-
-        TOPLEVEL = TOPLEVEL.wrap_enclose(arg_parameter_list);
-    }
-
-    var SCOPE_IS_NEEDED = COMPRESS || MANGLE || ARGS.lint;
-
-    if (SCOPE_IS_NEEDED) {
-        time_it("scope", function(){
-            TOPLEVEL.figure_out_scope({ screw_ie8: ARGS.screw_ie8 });
-            if (ARGS.lint) {
-                TOPLEVEL.scope_warnings();
-            }
-        });
-    }
-
-    if (COMPRESS) {
-        time_it("squeeze", function(){
-            TOPLEVEL = TOPLEVEL.transform(compressor);
-        });
-    }
-
-    if (SCOPE_IS_NEEDED) {
-        time_it("scope", function(){
-            TOPLEVEL.figure_out_scope({ screw_ie8: ARGS.screw_ie8 });
-            if (MANGLE) {
-                TOPLEVEL.compute_char_frequency(MANGLE);
-            }
-        });
-    }
-
-    if (MANGLE) time_it("mangle", function(){
-        TOPLEVEL.mangle_names(MANGLE);
-    });
-    time_it("generate", function(){
-        TOPLEVEL.print(output);
-    });
-
-    output = output.get();
-
-    if (SOURCE_MAP) {
-        fs.writeFileSync(ARGS.source_map, SOURCE_MAP, "utf8");
-        output += "\n/*\n//@ sourceMappingURL=" + (ARGS.source_map_url || ARGS.source_map) + "\n*/";
-    }
-
-    if (OUTPUT_FILE) {
-        fs.writeFileSync(OUTPUT_FILE, output, "utf8");
-    } else {
-        sys.print(output);
-        sys.error("\n");
-    }
-
-    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)
-            }));
-        }
-    }
+// workaround for tty output truncation upon process.exit()
+[process.stdout, process.stderr].forEach(function(stream){
+    if (stream._handle && stream._handle.setBlocking)
+        stream._handle.setBlocking(true);
 });
 
-/* -----[ functions ]----- */
+var fs = require("fs");
+var info = require("../package.json");
+var path = require("path");
+var program = require("commander");
+var UglifyJS = require("../tools/node");
 
-function normalize(o) {
-    for (var i in o) if (o.hasOwnProperty(i) && /-/.test(i)) {
-        o[i.replace(/-/g, "_")] = o[i];
-        delete o[i];
+var skip_keys = [ "cname", "enclosed", "parent_scope", "scope", "thedef", "uses_eval", "uses_with" ];
+var files = {};
+var options = {
+    compress: false,
+    mangle: false
+};
+program.version(info.name + " " + info.version);
+program.parseArgv = program.parse;
+program.parse = undefined;
+if (process.argv.indexOf("ast") >= 0) program.helpInformation = UglifyJS.describe_ast;
+else if (process.argv.indexOf("options") >= 0) program.helpInformation = function() {
+    var text = [];
+    var options = UglifyJS.default_options();
+    for (var option in options) {
+        text.push("--" + (option == "output" ? "beautify" : option == "sourceMap" ? "source-map" : option) + " options:");
+        var defs = options[option];
+        var padding = "";
+        Object.keys(defs).map(function(name) {
+            if (padding.length < name.length) padding = Array(name.length + 1).join(" ");
+            return [ name, JSON.stringify(defs[name]) ];
+        }).forEach(function(tokens) {
+            text.push("  " + tokens[0] + padding.slice(tokens[0].length - 2) + tokens[1]);
+        });
+        text.push("");
+    }
+    return text.join("\n");
+};
+program.option("-p, --parse <options>", "Specify parser options.", parse_js("parse", true));
+program.option("-c, --compress [options]", "Enable compressor/specify compressor options.", parse_js("compress", true));
+program.option("-m, --mangle [options]", "Mangle names/specify mangler options.", parse_js("mangle", true));
+program.option("--mangle-props [options]", "Mangle properties/specify mangler options.", parse_js("mangle-props", true));
+program.option("-b, --beautify [options]", "Beautify output/specify output options.", parse_js("beautify", true));
+program.option("-o, --output <file>", "Output file (default STDOUT).");
+program.option("--comments [filter]", "Preserve copyright comments in the output.");
+program.option("--config-file <file>", "Read minify() options from JSON file.");
+program.option("-d, --define <expr>[=value]", "Global definitions.", parse_js("define"));
+program.option("--ie8", "Support non-standard Internet Explorer 8.");
+program.option("--keep-fnames", "Do not mangle/drop function names. Useful for code relying on Function.prototype.name.");
+program.option("--name-cache <file>", "File to hold mangled name mappings.");
+program.option("--self", "Build UglifyJS as a library (implies --wrap UglifyJS)");
+program.option("--source-map [options]", "Enable source map/specify source map options.", parse_source_map());
+program.option("--timings", "Display operations run time on STDERR.")
+program.option("--toplevel", "Compress and/or mangle variables in toplevel scope.");
+program.option("--verbose", "Print diagnostic messages.");
+program.option("--warn", "Print warning messages.");
+program.option("--wrap <name>", "Embed everything as a function with “exports” corresponding to “name” globally.");
+program.arguments("[files...]").parseArgv(process.argv);
+if (program.configFile) {
+    options = JSON.parse(read_file(program.configFile));
+}
+if (!program.output && program.sourceMap && program.sourceMap.url != "inline") {
+    fatal("ERROR: cannot write source map to STDOUT");
+}
+[
+    "compress",
+    "ie8",
+    "mangle",
+    "sourceMap",
+    "toplevel",
+    "wrap"
+].forEach(function(name) {
+    if (name in program) {
+        options[name] = program[name];
+    }
+});
+if (program.beautify) {
+    options.output = typeof program.beautify == "object" ? program.beautify : {};
+    if (!("beautify" in options.output)) {
+        options.output.beautify = true;
     }
 }
+if (program.comments) {
+    if (typeof options.output != "object") options.output = {};
+    options.output.comments = typeof program.comments == "string" ? program.comments : "some";
+}
+if (program.define) {
+    if (typeof options.compress != "object") options.compress = {};
+    if (typeof options.compress.global_defs != "object") options.compress.global_defs = {};
+    for (var expr in program.define) {
+        options.compress.global_defs[expr] = program.define[expr];
+    }
+}
+if (program.keepFnames) {
+    options.keep_fnames = true;
+}
+if (program.mangleProps) {
+    if (program.mangleProps.domprops) {
+        delete program.mangleProps.domprops;
+    } else {
+        if (typeof program.mangleProps != "object") program.mangleProps = {};
+        if (!Array.isArray(program.mangleProps.reserved)) program.mangleProps.reserved = [];
+        require("../tools/domprops").forEach(function(name) {
+            UglifyJS._push_uniq(program.mangleProps.reserved, name);
+        });
+    }
+    if (typeof options.mangle != "object") options.mangle = {};
+    options.mangle.properties = program.mangleProps;
+}
+var cache;
+if (program.nameCache) {
+    cache = JSON.parse(read_file(program.nameCache, "{}"));
+    if (options.mangle) {
+        if (typeof options.mangle != "object") options.mangle = {};
+        options.mangle.cache = to_cache("vars");
+        if (options.mangle.properties) {
+            if (typeof options.mangle.properties != "object") options.mangle.properties = {};
+            options.mangle.properties.cache = to_cache("props");
+        }
+    }
+}
+if (program.output == "ast") {
+    options.output = {
+        ast: true,
+        code: false
+    };
+}
+if (program.parse) {
+    if (!program.parse.acorn && !program.parse.spidermonkey) {
+        options.parse = program.parse;
+    } else if (program.sourceMap && program.sourceMap.content == "inline") {
+        fatal("ERROR: inline source map only works with built-in parser");
+    }
+}
+var convert_path = function(name) {
+    return name;
+};
+if (typeof program.sourceMap == "object" && "base" in program.sourceMap) {
+    convert_path = function() {
+        var base = program.sourceMap.base;
+        delete options.sourceMap.base;
+        return function(name) {
+            return path.relative(base, name);
+        };
+    }();
+}
+if (program.verbose) {
+    options.warnings = "verbose";
+} else if (program.warn) {
+    options.warnings = true;
+}
+if (program.self) {
+    if (program.args.length) {
+        console.error("WARN: Ignoring input files since --self was passed");
+    }
+    if (!options.wrap) options.wrap = "UglifyJS";
+    simple_glob(UglifyJS.FILES).forEach(function(name) {
+        files[convert_path(name)] = read_file(name);
+    });
+    run();
+} else if (program.args.length) {
+    simple_glob(program.args).forEach(function(name) {
+        files[convert_path(name)] = read_file(name);
+    });
+    run();
+} else {
+    var chunks = [];
+    process.stdin.setEncoding("utf8");
+    process.stdin.on("data", function(chunk) {
+        chunks.push(chunk);
+    }).on("end", function() {
+        files = [ chunks.join("") ];
+        run();
+    });
+    process.stdin.resume();
+}
 
-function getOptions(x, constants) {
-    x = ARGS[x];
-    if (!x) return null;
-    var ret = {};
-    if (x !== true) {
-        var ast;
-        try {
-            ast = UglifyJS.parse(x);
-        } catch(ex) {
-            if (ex instanceof UglifyJS.JS_Parse_Error) {
-                sys.error("Error parsing arguments in: " + x);
-                process.exit(1);
+function convert_ast(fn) {
+    return UglifyJS.AST_Node.from_mozilla_ast(Object.keys(files).reduce(fn, null));
+}
+
+function run() {
+    UglifyJS.AST_Node.warn_function = function(msg) {
+        console.error("WARN:", msg);
+    };
+    if (program.timings) options.timings = true;
+    try {
+        if (program.parse) {
+            if (program.parse.acorn) {
+                files = convert_ast(function(toplevel, name) {
+                    return require("acorn").parse(files[name], {
+                        locations: true,
+                        program: toplevel,
+                        sourceFile: name
+                    });
+                });
+            } else if (program.parse.spidermonkey) {
+                files = convert_ast(function(toplevel, name) {
+                    var obj = JSON.parse(files[name]);
+                    if (!toplevel) return obj;
+                    toplevel.body = toplevel.body.concat(obj.body);
+                    return toplevel;
+                });
             }
         }
-        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 value = node.right;
-                if (constants)
-                    value = new Function("return (" + value.print_to_string() + ")")();
-                ret[name] = value;
-                return true;    // no descend
+    } catch (ex) {
+        fatal(ex);
+    }
+    var result = UglifyJS.minify(files, options);
+    if (result.error) {
+        var ex = result.error;
+        if (ex.name == "SyntaxError") {
+            console.error("Parse error at " + ex.filename + ":" + ex.line + "," + ex.col);
+            var col = ex.col;
+            var lines = files[ex.filename].split(/\r?\n/);
+            var line = lines[ex.line - 1];
+            if (!line && !col) {
+                line = lines[ex.line - 2];
+                col = line.length;
             }
-            sys.error(node.TYPE)
-            sys.error("Error parsing arguments in: " + x);
-            process.exit(1);
+            if (line) {
+                if (col > 40) {
+                    line = line.slice(col - 40);
+                    col = 40;
+                }
+                console.error(line.slice(0, 80));
+                console.error(line.slice(0, col).replace(/\S/g, " ") + "^");
+            }
+        }
+        if (ex.defs) {
+            console.error("Supported options:");
+            console.error(ex.defs);
+        }
+        fatal(ex);
+    } else if (program.output == "ast") {
+        console.log(JSON.stringify(result.ast, function(key, value) {
+            if (skip_key(key)) return;
+            if (value instanceof UglifyJS.AST_Token) return;
+            if (value instanceof UglifyJS.Dictionary) return;
+            if (value instanceof UglifyJS.AST_Node) {
+                var result = {
+                    _class: "AST_" + value.TYPE
+                };
+                value.CTOR.PROPS.forEach(function(prop) {
+                    result[prop] = value[prop];
+                });
+                return result;
+            }
+            return value;
+        }, 2));
+    } else if (program.output == "spidermonkey") {
+        console.log(JSON.stringify(UglifyJS.minify(result.code, {
+            compress: false,
+            mangle: false,
+            output: {
+                ast: true,
+                code: false
+            }
+        }).ast.to_mozilla_ast(), null, 2));
+    } else if (program.output) {
+        fs.writeFileSync(program.output, result.code);
+        if (result.map) {
+            fs.writeFileSync(program.output + ".map", result.map);
+        }
+    } else {
+        console.log(result.code);
+    }
+    if (program.nameCache) {
+        fs.writeFileSync(program.nameCache, JSON.stringify(cache, function(key, value) {
+            return value instanceof UglifyJS.Dictionary ? value.toObject() : value;
         }));
     }
-    return ret;
+    if (result.timings) for (var phase in result.timings) {
+        console.error("- " + phase + ": " + result.timings[phase].toFixed(3) + "s");
+    }
 }
 
-function read_whole_file(filename, cb) {
-    if (filename == "-") {
-        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();
+function fatal(message) {
+    if (message instanceof Error) message = message.stack.replace(/^\S*?Error:/, "ERROR:")
+    console.error(message);
+    process.exit(1);
+}
+
+// A file glob function that only supports "*" and "?" wildcards in the basename.
+// Example: "foo/bar/*baz??.*.js"
+// Argument `glob` may be a string or an array of strings.
+// Returns an array of strings. Garbage in, garbage out.
+function simple_glob(glob) {
+    if (Array.isArray(glob)) {
+        return [].concat.apply([], glob.map(simple_glob));
+    }
+    if (glob.match(/\*|\?/)) {
+        var dir = path.dirname(glob);
+        try {
+            var entries = fs.readdirSync(dir);
+        } catch (ex) {}
+        if (entries) {
+            var pattern = "^" + path.basename(glob)
+                .replace(/[.+^$[\]\\(){}]/g, "\\$&")
+                .replace(/\*/g, "[^/\\\\]*")
+                .replace(/\?/g, "[^/\\\\]") + "$";
+            var mod = process.platform === "win32" ? "i" : "";
+            var rx = new RegExp(pattern, mod);
+            var results = entries.filter(function(name) {
+                return rx.test(name);
+            }).map(function(name) {
+                return path.join(dir, name);
+            });
+            if (results.length) return results;
+        }
+    }
+    return [ glob ];
+}
+
+function read_file(path, default_value) {
+    try {
+        return fs.readFileSync(path, "utf8");
+    } catch (ex) {
+        if (ex.code == "ENOENT" && default_value != null) return default_value;
+        fatal(ex);
+    }
+}
+
+function parse_js(flag, constants) {
+    return function(value, options) {
+        options = options || {};
+        try {
+            UglifyJS.minify(value, {
+                parse: {
+                    expression: true
+                },
+                compress: false,
+                mangle: false,
+                output: {
+                    ast: true,
+                    code: false
+                }
+            }).ast.walk(new UglifyJS.TreeWalker(function(node) {
+                if (node instanceof UglifyJS.AST_Assign) {
+                    var name = node.left.print_to_string();
+                    var value = node.right;
+                    if (!constants) {
+                        options[name] = value;
+                    } else if (value instanceof UglifyJS.AST_Array) {
+                        options[name] = value.elements.map(to_string);
+                    } else {
+                        options[name] = to_string(value);
+                    }
+                    return true;
+                }
+                if (node instanceof UglifyJS.AST_Symbol || node instanceof UglifyJS.AST_PropAccess) {
+                    var name = node.print_to_string();
+                    options[name] = true;
+                    return true;
+                }
+                if (!(node instanceof UglifyJS.AST_Sequence)) throw node;
+
+                function to_string(value) {
+                    return value instanceof UglifyJS.AST_Constant ? value.getValue() : value.print_to_string({
+                        quote_keys: true
+                    });
+                }
+            }));
+        } catch(ex) {
+            options[value] = null;
+        }
+        return options;
+    }
+}
+
+function parse_source_map() {
+    var parse = parse_js("sourceMap", true);
+    return function(value, options) {
+        var hasContent = options && options.sourceMap && "content" in options.sourceMap;
+        var settings = parse(value, options);
+        if (!hasContent && settings.content && settings.content != "inline") {
+            console.error("INFO: Using input source map:", settings.content);
+            settings.content = read_file(settings.content, settings.content);
+        }
+        return settings;
+    }
+}
+
+function to_cache(key) {
+    if (cache[key]) {
+        cache[key].props = UglifyJS.Dictionary.fromObject(cache[key].props);
     } else {
-        fs.readFile(filename, "utf-8", cb);
+        cache[key] = {
+            cname: -1,
+            props: new UglifyJS.Dictionary()
+        };
     }
+    return cache[key];
 }
 
-function time_it(name, cont) {
-    var t1 = new Date().getTime();
-    var ret = cont();
-    if (ARGS.stats) {
-        var spent = new Date().getTime() - t1;
-        if (STATS[name]) STATS[name] += spent;
-        else STATS[name] = spent;
-    }
-    return ret;
+function skip_key(key) {
+    return skip_keys.indexOf(key) >= 0;
 }

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", {
@@ -166,21 +182,13 @@ var AST_BlockStatement = DEFNODE("BlockStatement", null, {
 }, AST_Block);
 
 var AST_EmptyStatement = DEFNODE("EmptyStatement", null, {
-    $documentation: "The empty statement (empty block or simply a semicolon)",
-    _walk: function(visitor) {
-        return visitor._visit(this);
-    }
+    $documentation: "The empty statement (empty block or simply a semicolon)"
 }, AST_Statement);
 
 var AST_StatementWithBody = DEFNODE("StatementWithBody", "body", {
     $documentation: "Base class for all statements that contain one nested body: `For`, `ForIn`, `Do`, `While`, `With`",
     $propdoc: {
         body: "[AST_Statement] the body; this should always be present, even if it's an AST_EmptyStatement"
-    },
-    _walk: function(visitor) {
-        return visitor._visit(this, function(){
-            this.body._walk(visitor);
-        });
     }
 }, AST_Statement);
 
@@ -194,28 +202,53 @@ 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 label = node.label;
+            var def = this.label;
+            node.walk(new TreeWalker(function(node) {
+                if (node instanceof AST_LoopControl
+                    && node.label && node.label.thedef === def) {
+                    node.label.thedef = label;
+                    label.references.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 +266,7 @@ 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 +282,11 @@ 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 +315,13 @@ 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", {
@@ -285,99 +329,143 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     $propdoc: {
         globals: "[Object/S] a map of name -> SymbolDef for all undeclared names",
     },
-    wrap_enclose: function(arg_parameter_pairs) {
-        var self = this;
-        var args = [];
-        var parameters = [];
-
-        arg_parameter_pairs.forEach(function(pair) {
-            var split = pair.split(":");
-
-            args.push(split[0]);
-            parameters.push(split[1]);
-        });
-
-        var wrapped_tl = "(function(" + parameters.join(",") + "){ '$ORIG'; })(" + args.join(",") + ")";
+    wrap_commonjs: function(name) {
+        var body = this.body;
+        var wrapped_tl = "(function(exports){'$ORIG';})(typeof " + name + "=='undefined'?(" + name + "={}):" + name + ");";
         wrapped_tl = parse(wrapped_tl);
         wrapped_tl = wrapped_tl.transform(new TreeTransformer(function before(node){
             if (node instanceof AST_Directive && node.value == "$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();
-            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))
-                        to_export.push(node);
-                }
-            }));
-        }
-        var wrapped_tl = "(function(exports, global){ global['" + name + "'] = exports; '$ORIG'; '$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()) {
-                  case "$ORIG":
-                    return MAP.splice(self.body);
-                  case "$EXPORTS":
-                    var body = [];
-                    to_export.forEach(function(sym){
-                        body.push(new AST_SimpleStatement({
-                            body: new AST_Assign({
-                                left: new AST_Sub({
-                                    expression: new AST_SymbolRef({ name: "exports" }),
-                                    property: new AST_String({ value: sym.name }),
-                                }),
-                                operator: "=",
-                                right: new AST_SymbolRef(sym),
-                            }),
-                        }));
-                    });
-                    return MAP.splice(body);
-                }
+                return MAP.splice(body);
             }
         }));
         return wrapped_tl;
     }
 }, 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_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, {
@@ -494,16 +582,10 @@ 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(){
@@ -526,9 +608,10 @@ 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);
@@ -537,14 +620,75 @@ 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) {
@@ -565,10 +709,11 @@ var AST_Call = DEFNODE("Call", "expression args", {
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
+            var args = this.args;
+            for (var i = 0, len = args.length; i < len; i++) {
+                args[i]._walk(visitor);
+            }
             this.expression._walk(visitor);
-            this.args.forEach(function(arg){
-                arg._walk(visitor);
-            });
         });
     }
 });
@@ -577,61 +722,16 @@ var AST_New = DEFNODE("New", null, {
     $documentation: "An object instantiation.  Derives from a function call since it has exactly the same properties"
 }, AST_Call);
 
-var AST_Seq = DEFNODE("Seq", "car cdr", {
-    $documentation: "A sequence expression (two comma-separated expressions)",
+var AST_Sequence = DEFNODE("Sequence", "expressions", {
+    $documentation: "A sequence expression (comma-separated expressions)",
     $propdoc: {
-        car: "[AST_Node] first element in sequence",
-        cdr: "[AST_Node] second element in sequence"
-    },
-    $cons: function(x, y) {
-        var seq = new AST_Seq(x);
-        seq.car = x;
-        seq.cdr = y;
-        return seq;
-    },
-    $from_array: function(array) {
-        if (array.length == 0) return null;
-        if (array.length == 1) return array[0].clone();
-        var list = null;
-        for (var i = array.length; --i >= 0;) {
-            list = AST_Seq.cons(array[i], list);
-        }
-        var p = list;
-        while (p) {
-            if (p.cdr && !p.cdr.cdr) {
-                p.cdr = p.cdr.car;
-                break;
-            }
-            p = p.cdr;
-        }
-        return list;
-    },
-    to_array: function() {
-        var p = this, a = [];
-        while (p) {
-            a.push(p.car);
-            if (p.cdr && !(p.cdr instanceof AST_Seq)) {
-                a.push(p.cdr);
-                break;
-            }
-            p = p.cdr;
-        }
-        return a;
-    },
-    add: function(node) {
-        var p = this;
-        while (p) {
-            if (!(p.cdr instanceof AST_Seq)) {
-                var cell = AST_Seq.cons(p.cdr, node);
-                return p.cdr = cell;
-            }
-            p = p.cdr;
-        }
+        expressions: "[AST_Node*] array of expressions (at least two)"
     },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
-            this.car._walk(visitor);
-            if (this.cdr) this.cdr._walk(visitor);
+            this.expressions.forEach(function(node) {
+                node._walk(visitor);
+            });
         });
     }
 });
@@ -684,7 +784,7 @@ var AST_UnaryPostfix = DEFNODE("UnaryPostfix", null, {
     $documentation: "Unary postfix expression, i.e. `i++`"
 }, AST_Unary);
 
-var AST_Binary = DEFNODE("Binary", "left operator right", {
+var AST_Binary = DEFNODE("Binary", "operator left right", {
     $documentation: "Binary expression, i.e. `a + b`",
     $propdoc: {
         left: "[AST_Node] left-hand side expression",
@@ -719,6 +819,10 @@ 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", {
@@ -728,9 +832,10 @@ 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);
+            }
         });
     }
 });
@@ -742,9 +847,10 @@ 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);
+            }
         });
     }
 });
@@ -752,55 +858,112 @@ 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_Accessor."
     },
     _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_SymbolAccessor = DEFNODE("SymbolAccessor", null, {
-    $documentation: "The name of a property accessor (setter/getter function)"
-}, AST_Symbol);
+var AST_NewTarget = DEFNODE("NewTarget", null, {
+    $documentation: "A reference to new.target"
+});
 
 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",
@@ -810,18 +973,42 @@ 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);
 
@@ -837,6 +1024,10 @@ 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() {
@@ -844,17 +1035,19 @@ 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);
 
@@ -908,32 +1101,61 @@ 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) {
+    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];
@@ -945,6 +1167,18 @@ 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];
@@ -963,23 +1197,17 @@ TreeWalker.prototype = {
             self = p;
         }
     },
-    loopcontrol_target: function(label) {
+    loopcontrol_target: function(node) {
         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 (node.label) for (var i = stack.length; --i >= 0;) {
+            var x = stack[i];
+            if (x instanceof AST_LabeledStatement && x.label.name == node.label.name)
+                return x.body;
+        } else for (var i = stack.length; --i >= 0;) {
+            var x = stack[i];
+            if (x instanceof AST_IterationStatement
+                || node instanceof AST_Break && x instanceof AST_Switch)
+                return x;
         }
     }
 };

lib/minify.js

@@ -0,0 +1,179 @@
+"use strict";
+
+var to_ascii = typeof atob == "undefined" ? function(b64) {
+    return new Buffer(b64, "base64").toString();
+} : atob;
+var to_base64 = typeof btoa == "undefined" ? function(str) {
+    return new Buffer(str).toString("base64");
+} : btoa;
+
+function read_source_map(code) {
+    var match = /\n\/\/# sourceMappingURL=data:application\/json(;.*?)?;base64,(.*)/.exec(code);
+    if (!match) {
+        AST_Node.warn("inline source map not found");
+        return null;
+    }
+    return to_ascii(match[2]);
+}
+
+function set_shorthand(name, options, keys) {
+    if (options[name]) {
+        keys.forEach(function(key) {
+            if (options[key]) {
+                if (typeof options[key] != "object") options[key] = {};
+                if (!(name in options[key])) options[key][name] = options[name];
+            }
+        });
+    }
+}
+
+function minify(files, options) {
+    var warn_function = AST_Node.warn_function;
+    try {
+        options = defaults(options, {
+            compress: {},
+            ie8: false,
+            keep_fnames: false,
+            mangle: {},
+            output: {},
+            parse: {},
+            sourceMap: false,
+            timings: false,
+            toplevel: false,
+            warnings: false,
+            wrap: false,
+        }, true);
+        var timings = options.timings && {
+            start: Date.now()
+        };
+        set_shorthand("ie8", options, [ "compress", "mangle", "output" ]);
+        set_shorthand("keep_fnames", options, [ "compress", "mangle" ]);
+        set_shorthand("toplevel", options, [ "compress", "mangle" ]);
+        set_shorthand("warnings", options, [ "compress" ]);
+        if (options.mangle) {
+            options.mangle = defaults(options.mangle, {
+                cache: null,
+                eval: false,
+                ie8: false,
+                keep_classnames: false,
+                keep_fnames: false,
+                properties: false,
+                reserved: [],
+                safari10: false,
+                toplevel: false,
+            }, true);
+        }
+        if (options.sourceMap) {
+            options.sourceMap = defaults(options.sourceMap, {
+                content: null,
+                filename: null,
+                includeSources: false,
+                root: null,
+                url: null,
+            }, true);
+        }
+        var warnings = [];
+        if (options.warnings && !AST_Node.warn_function) {
+            AST_Node.warn_function = function(warning) {
+                warnings.push(warning);
+            };
+        }
+        if (timings) timings.parse = Date.now();
+        var toplevel;
+        if (files instanceof AST_Toplevel) {
+            toplevel = files;
+        } else {
+            if (typeof files == "string") {
+                files = [ files ];
+            }
+            options.parse = options.parse || {};
+            options.parse.toplevel = null;
+            for (var name in files) {
+                options.parse.filename = name;
+                options.parse.toplevel = parse(files[name], options.parse);
+                if (options.sourceMap && options.sourceMap.content == "inline") {
+                    if (Object.keys(files).length > 1)
+                        throw new Error("inline source map only works with singular input");
+                    options.sourceMap.content = read_source_map(files[name]);
+                }
+            }
+            toplevel = options.parse.toplevel;
+        }
+        if (options.wrap) {
+            toplevel = toplevel.wrap_commonjs(options.wrap);
+        }
+        if (timings) timings.scope1 = Date.now();
+        if (options.compress) toplevel.figure_out_scope(options.mangle);
+        if (timings) timings.compress = Date.now();
+        if (options.compress) toplevel = new Compressor(options.compress).compress(toplevel);
+        if (timings) timings.scope2 = Date.now();
+        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);
+        }
+        if (timings) timings.properties = Date.now();
+        if (options.mangle && options.mangle.properties) {
+            toplevel = mangle_properties(toplevel, options.mangle.properties);
+        }
+        if (timings) timings.output = Date.now();
+        var result = {};
+        if (options.output.ast) {
+            result.ast = toplevel;
+        }
+        if (!HOP(options.output, "code") || options.output.code) {
+            if (options.sourceMap) {
+                if (typeof options.sourceMap.content == "string") {
+                    options.sourceMap.content = JSON.parse(options.sourceMap.content);
+                }
+                options.output.source_map = SourceMap({
+                    file: options.sourceMap.filename,
+                    orig: options.sourceMap.content,
+                    root: options.sourceMap.root
+                });
+                if (options.sourceMap.includeSources) {
+                    if (files instanceof AST_Toplevel) {
+                        throw new Error("original source content unavailable");
+                    } else for (var name in files) {
+                        options.output.source_map.get().setSourceContent(name, files[name]);
+                    }
+                }
+            }
+            delete options.output.ast;
+            delete options.output.code;
+            var stream = OutputStream(options.output);
+            toplevel.print(stream);
+            result.code = stream.get();
+            if (options.sourceMap) {
+                result.map = options.output.source_map.toString();
+                if (options.sourceMap.url == "inline") {
+                    result.code += "\n//# sourceMappingURL=data:application/json;charset=utf-8;base64," + to_base64(result.map);
+                } else if (options.sourceMap.url) {
+                    result.code += "\n//# sourceMappingURL=" + options.sourceMap.url;
+                }
+            }
+        }
+        if (timings) {
+            timings.end = Date.now();
+            result.timings = {
+                parse: 1e-3 * (timings.scope1 - timings.parse),
+                scope: 1e-3 * (timings.compress - timings.scope1 + timings.mangle - timings.scope2),
+                compress: 1e-3 * (timings.scope2 - timings.compress),
+                mangle: 1e-3 * (timings.properties - timings.mangle),
+                properties: 1e-3 * (timings.output - timings.properties),
+                output: 1e-3 * (timings.end - timings.output),
+                total: 1e-3 * (timings.end - timings.start)
+            }
+        }
+        if (warnings.length) {
+            result.warnings = warnings;
+        }
+        return result;
+    } catch (ex) {
+        return { error: ex };
+    } finally {
+        AST_Node.warn_function = warn_function;
+    }
+}

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 args = {
+                start    : my_start_token(key),
+                end      : my_end_token(M.value),
+                key      : key.type == "Identifier" ? key.name : key.value,
+                value    : from_moz(M.value)
+            };
+            if (M.kind == "init") return new AST_ObjectKeyVal(args);
+            args.key = new AST_SymbolMethod({
+                name: args.key
+            });
+            args.value = new AST_Accessor(args.value);
+            if (M.kind == "get") return new AST_ObjectGetter(args);
+            if (M.kind == "set") return new AST_ObjectSetter(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) {
-            return AST_Seq.from_array(M.expressions.map(from_moz));
+        SequenceExpression: function(M) {
+            return new AST_Sequence({
+                start      : my_start_token(M),
+                end        : my_end_token(M),
+                expressions: 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)
@@ -147,7 +217,8 @@
         }
     };
 
-    function From_Moz_Unary(M) {
+    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)({
@@ -158,14 +229,8 @@
         });
     };
 
-    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");
@@ -179,72 +244,310 @@
     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 to_moz_scope("Program", M);
+    });
+
+    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_scope("BlockStatement", 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_scope("BlockStatement", 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_Sequence, function To_Moz_SequenceExpression(M) {
+        return {
+            type: "SequenceExpression",
+            expressions: M.expressions.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 = {
+            type: "Literal",
+            value: M.key instanceof AST_SymbolMethod ? M.key.name : 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", "to_moz_scope", "return(" + me_to_moz + ")")(
+            to_moz, to_moz_block, to_moz_scope
+        );
+        MOZ_TO_ME[moztype] = moz_to_me;
+        def_to_moz(mytype, me_to_moz);
     };
 
     var FROM_MOZ_STACK = null;
@@ -264,4 +567,49 @@
         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)
+        };
+    };
+
+    function to_moz_scope(type, node) {
+        var body = node.body.map(to_moz);
+        if (node.body[0] instanceof AST_SimpleStatement && node.body[0].body instanceof AST_String) {
+            body.unshift(to_moz(new AST_EmptyStatement(node.body[0])));
+        }
+        return {
+            type: type,
+            body: body
+        };
+    };
 })();

lib/propmangle.js

@@ -0,0 +1,289 @@
+/***********************************************************************
+
+  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(reserved) {
+
+    // 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 = {};
+    var global_ref = typeof global === "object" ? global : self;
+
+    new_globals.forEach(function (new_global) {
+        objects[new_global] = global_ref[new_global] || new Function();
+    });
+
+    // NaN will be included due to Number.NaN
+    [
+        "null",
+        "true",
+        "false",
+        "Infinity",
+        "-Infinity",
+        "undefined",
+    ].forEach(add);
+    [ 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(reserved, name);
+    }
+}
+
+function mangle_properties(ast, options) {
+    options = defaults(options, {
+        builtins: false,
+        cache: null,
+        debug: false,
+        keep_quoted: false,
+        only_cache: false,
+        regex: null,
+        reserved: null,
+    });
+
+    var reserved = options.reserved || [];
+    if (!options.builtins) find_builtins(reserved);
+
+    var cache = options.cache;
+    if (cache == null) {
+        cache = {
+            cname: -1,
+            props: new Dictionary()
+        };
+    }
+
+    var regex = options.regex;
+    var keep_quoted = options.keep_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 to_keep = {};
+
+    // step 1: find candidates to mangle
+    ast.walk(new TreeWalker(function(node){
+        if (node instanceof AST_ObjectKeyVal) {
+            add(node.key, keep_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, keep_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 (!(keep_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 (!keep_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 (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]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
+        return true;
+    }
+
+    function should_mangle(name) {
+        if (keep_quoted && name in to_keep) return false;
+        if (regex && !regex.test(name)) return false;
+        if (reserved.indexOf(name) >= 0) return false;
+        return cache.props.has(name)
+            || names_to_mangle.indexOf(name) >= 0;
+    }
+
+    function add(name, keep) {
+        if (keep) {
+            to_keep[name] = true;
+            return;
+        }
+
+        if (can_mangle(name))
+            push_uniq(names_to_mangle, name);
+
+        if (!should_mangle(name)) {
+            push_uniq(unmangleable, name);
+        }
+    }
+
+    function mangle(name) {
+        if (!should_mangle(name)) {
+            return name;
+        }
+
+        var mangled = cache.props.get(name);
+        if (!mangled) {
+            if (debug) {
+                // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
+                var debug_mangled = "_$" + name + "$" + debug_name_suffix + "_";
+
+                if (can_mangle(debug_mangled) && !(keep_quoted && debug_mangled in to_keep)) {
+                    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 `to_keep` set
+                // (filled with quoted properties when `keep_quoted` is 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) || keep_quoted && mangled in to_keep);
+            }
+
+            cache.props.set(name, mangled);
+        }
+        return mangled;
+    }
+
+    function addStrings(node, keep) {
+        var out = {};
+        try {
+            (function walk(node){
+                node.walk(new TreeWalker(function(node){
+                    if (node instanceof AST_Sequence) {
+                        walk(node.expressions[node.expressions.length - 1]);
+                        return true;
+                    }
+                    if (node instanceof AST_String) {
+                        add(node.value, keep);
+                        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_Sequence) {
+                var last = node.expressions.length - 1;
+                node.expressions[last] = mangleStrings(node.expressions[last]);
+            }
+            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

@@ -49,83 +49,134 @@ 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 && !(options && options.toplevel))
+        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)) {
+        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;
-            if (this.orig[0] instanceof AST_SymbolLambda && !options.screw_ie8)
+            var sym = this.orig[0];
+            if (options.ie8 && sym instanceof AST_SymbolLambda)
                 s = s.parent_scope;
-            this.mangled_name = s.next_mangled(options);
+            var def;
+            if (this.defun && (def = this.defun.variables.get(this.name))) {
+                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, {
+        cache: null,
+        ie8: false,
+        safari10: false,
+    });
 
     // 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 for_scopes = [];
     var tw = new TreeWalker(function(node, descend){
+        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;
+            }
+            if (options.safari10) {
+                if (node instanceof AST_For || node instanceof AST_ForIn) {
+                    for_scopes.push(scope);
+                }
+            }
+            descend();
+            scope = save_scope;
+            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(nesting);
-            var save_scope = node.parent_scope = scope;
+            node.init_scope_vars(scope);
+            var save_scope = scope;
+            var save_defun = defun;
             var save_labels = labels;
-            ++nesting;
-            scope = node;
+            defun = scope = node;
             labels = new Dictionary();
             descend();
-            labels = save_labels;
             scope = save_scope;
-            --nesting;
+            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);
-            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_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);
+            defun.def_function(node);
         }
         else if (node instanceof AST_SymbolDefun) {
             // Careful here, the scope where this should be defined is
@@ -133,24 +184,42 @@ 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);
+            var parent_lambda = defun.parent_scope;
+            while (parent_lambda.is_block_scope()) {
+                parent_lambda = parent_lambda.parent_scope;
+            }
+            mark_export((node.scope = parent_lambda).def_function(node), 1);
         }
-        else if (node instanceof AST_SymbolVar
-                 || node instanceof AST_SymbolConst) {
-            var def = scope.def_variable(node);
-            def.constant = node instanceof AST_SymbolConst;
-            def.init = tw.parent().value;
+        else if (node instanceof AST_SymbolClass) {
+            mark_export(defun.def_variable(node), 1);
         }
-        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)
+        else if (node instanceof AST_SymbolImport) {
             scope.def_variable(node);
         }
-        if (node instanceof AST_LabelRef) {
+        else if (node instanceof AST_SymbolDefClass) {
+            // This deals with the name of the class being available
+            // inside the class.
+            mark_export((node.scope = defun.parent_scope).def_function(node), 1);
+        }
+        else if (node instanceof AST_SymbolVar
+            || node instanceof AST_SymbolLet
+            || node instanceof AST_SymbolConst) {
+            var def = ((node instanceof AST_SymbolBlockDeclaration) ? scope : defun).def_variable(node);
+            if (!(node instanceof AST_SymbolFunarg)) mark_export(def, 2);
+            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) {
+            scope.def_variable(node).defun = defun;
+        }
+        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,
@@ -159,93 +228,137 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             }));
             node.thedef = sym;
         }
+
+        function mark_export(def, level) {
+            var node = tw.parent(level);
+            def.export = node instanceof AST_Export && !node.is_default;
+        }
     });
     self.walk(tw);
 
     // pass 2: find back references and eval
-    var func = null;
-    var globals = self.globals = new Dictionary();
+    self.globals = new Dictionary();
     var tw = new TreeWalker(function(node, descend){
-        if (node instanceof AST_Lambda) {
-            var prev_func = func;
-            func = node;
-            descend();
-            func = prev_func;
-            return true;
-        }
-        if (node instanceof AST_LabelRef) {
-            node.reference();
+        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.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.defun;
+                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;
+            }
+        }));
+    }
+
+    // pass 4: add symbol definitions to loop scopes
+    // Safari/Webkit bug workaround - loop init let variable shadowing argument.
+    // https://github.com/mishoo/UglifyJS2/issues/1753
+    // https://bugs.webkit.org/show_bug.cgi?id=171041
+    if (options.safari10) {
+        for (var i = 0; i < for_scopes.length; i++) {
+            var scope = for_scopes[i];
+            scope.parent_scope.variables.each(function(def) {
+                push_uniq(scope.enclosed, def);
+            });
+        }
+    }
+
+    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", return_false);
+AST_Class.DEFMETHOD("is_block_scope", return_false);
+AST_Lambda.DEFMETHOD("is_block_scope", return_false);
+AST_Toplevel.DEFMETHOD("is_block_scope", return_false);
+AST_SwitchBranch.DEFMETHOD("is_block_scope", return_false);
+AST_Block.DEFMETHOD("is_block_scope", return_true);
+AST_IterationStatement.DEFMETHOD("is_block_scope", 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_SymbolConst({
+        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_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){
@@ -254,13 +367,10 @@ 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){
-    this.functions.set(symbol.name, this.def_variable(symbol));
+    var def = this.def_variable(symbol);
+    this.functions.set(symbol.name, def);
+    return def;
 });
 
 AST_Scope.DEFMETHOD("def_variable", function(symbol){
@@ -268,6 +378,7 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol){
     if (!this.variables.has(symbol.name)) {
         def = new SymbolDef(this, this.variables.size(), symbol);
         this.variables.set(symbol.name, def);
+        def.object_destructuring_arg = symbol.object_destructuring_arg;
         def.global = !this.parent_scope;
     } else {
         def = this.variables.get(symbol.name);
@@ -281,6 +392,11 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
     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 reserved from mangling.
+        if (options.reserved.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.
@@ -293,24 +409,30 @@ 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);
-});
-
-// property accessors are not mangleable
-AST_SymbolAccessor.DEFMETHOD("unmangleable", function(){
-    return true;
+    var def = this.definition();
+    return def && def.unmangleable(options);
 });
 
 // labels are always mangleable
-AST_Label.DEFMETHOD("unmangleable", function(){
-    return false;
-});
+AST_Label.DEFMETHOD("unmangleable", return_false);
 
 AST_Symbol.DEFMETHOD("unreferenced", function(){
     return this.definition().references.length == 0
@@ -321,13 +443,9 @@ AST_Symbol.DEFMETHOD("undeclared", function(){
     return this.definition().undeclared;
 });
 
-AST_LabelRef.DEFMETHOD("undeclared", function(){
-    return false;
-});
+AST_LabelRef.DEFMETHOD("undeclared", return_false);
 
-AST_Label.DEFMETHOD("undeclared", function(){
-    return false;
-});
+AST_Label.DEFMETHOD("undeclared", return_false);
 
 AST_Symbol.DEFMETHOD("definition", function(){
     return this.thedef;
@@ -339,22 +457,36 @@ AST_Symbol.DEFMETHOD("global", function(){
 
 AST_Toplevel.DEFMETHOD("_default_mangler_options", function(options){
     return defaults(options, {
-        except   : [],
-        eval     : false,
-        sort     : false,
-        toplevel : false,
-        screw_ie8 : false
+        eval        : false,
+        ie8         : false,
+        keep_classnames: false,
+        keep_fnames : false,
+        reserved    : [],
+        toplevel    : false,
     });
 });
 
 AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     options = this._default_mangler_options(options);
+
+    // Never mangle arguments
+    options.reserved.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.reserved.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
@@ -366,13 +498,10 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
         if (node instanceof AST_Scope) {
             var p = tw.parent(), a = [];
             node.variables.each(function(symbol){
-                if (options.except.indexOf(symbol.name) < 0) {
+                if (options.reserved.indexOf(symbol.name) < 0) {
                     a.push(symbol);
                 }
             });
-            if (options.sort) a.sort(function(a, b){
-                return b.references.length - a.references.length;
-            });
             to_mangle.push.apply(to_mangle, a);
             return;
         }
@@ -382,9 +511,22 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             node.mangled_name = name;
             return true;
         }
+        var mangle_with_block_scope =
+            (!options.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){
+        def.mangle(options);
+    });
+
+    if (options.cache) {
+        options.cache.cname = this.cname;
+    }
 });
 
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
@@ -431,21 +573,27 @@ 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)
@@ -484,7 +632,9 @@ 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;
@@ -493,88 +643,3 @@ var base54 = (function() {
     };
     return base54;
 })();
-
-AST_Toplevel.DEFMETHOD("scope_warnings", function(options){
-    options = defaults(options, {
-        undeclared       : false, // this makes a lot of noise
-        unreferenced     : true,
-        assign_to_global : true,
-        func_arguments   : true,
-        nested_defuns    : true,
-        eval             : true
-    });
-    var tw = new TreeWalker(function(node){
-        if (options.undeclared
-            && node instanceof AST_SymbolRef
-            && node.undeclared())
-        {
-            // XXX: this also warns about JS standard names,
-            // i.e. Object, Array, parseInt etc.  Should add a list of
-            // exceptions.
-            AST_Node.warn("Undeclared symbol: {name} [{file}:{line},{col}]", {
-                name: node.name,
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-        if (options.assign_to_global)
-        {
-            var sym = null;
-            if (node instanceof AST_Assign && node.left instanceof AST_SymbolRef)
-                sym = node.left;
-            else if (node instanceof AST_ForIn && node.init instanceof AST_SymbolRef)
-                sym = node.init;
-            if (sym
-                && (sym.undeclared()
-                    || (sym.global() && sym.scope !== sym.definition().scope))) {
-                AST_Node.warn("{msg}: {name} [{file}:{line},{col}]", {
-                    msg: sym.undeclared() ? "Accidental global?" : "Assignment to global",
-                    name: sym.name,
-                    file: sym.start.file,
-                    line: sym.start.line,
-                    col: sym.start.col
-                });
-            }
-        }
-        if (options.eval
-            && node instanceof AST_SymbolRef
-            && node.undeclared()
-            && node.name == "eval") {
-            AST_Node.warn("Eval is used [{file}:{line},{col}]", node.start);
-        }
-        if (options.unreferenced
-            && (node instanceof AST_SymbolDeclaration || node instanceof AST_Label)
-            && node.unreferenced()) {
-            AST_Node.warn("{type} {name} is declared but not referenced [{file}:{line},{col}]", {
-                type: node instanceof AST_Label ? "Label" : "Symbol",
-                name: node.name,
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-        if (options.func_arguments
-            && node instanceof AST_Lambda
-            && node.uses_arguments) {
-            AST_Node.warn("arguments used in function {name} [{file}:{line},{col}]", {
-                name: node.name ? node.name.name : "anonymous",
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-        if (options.nested_defuns
-            && node instanceof AST_Defun
-            && !(tw.parent() instanceof AST_Scope)) {
-            AST_Node.warn("Function {name} declared in nested statement \"{type}\" [{file}:{line},{col}]", {
-                name: node.name.name,
-                type: tw.parent().TYPE,
-                file: node.start.file,
-                line: node.start.line,
-                col: node.start.col
-            });
-        }
-    });
-    this.walk(tw);
-});

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){
@@ -174,9 +182,8 @@ TreeTransformer.prototype = new TreeWalker;
         self.args = do_list(self.args, tw);
     });
 
-    _(AST_Seq, function(self, tw){
-        self.car = self.car.transform(tw);
-        self.cdr = self.cdr.transform(tw);
+    _(AST_Sequence, function(self, tw){
+        self.expressions = do_list(self.expressions, tw);
     });
 
     _(AST_Dot, function(self, tw){
@@ -188,6 +195,10 @@ 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 +223,37 @@ 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_Export, function(self, tw){
+        if (self.exported_definition) self.exported_definition = self.exported_definition.transform(tw);
+        if (self.exported_value) self.exported_value = self.exported_value.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;
@@ -284,5 +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_Sequence      && p.expressions[0] === 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

@@ -1,26 +1,44 @@
 {
-    "name": "uglify-js",
-    "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
-    "homepage": "http://lisperator.net/uglifyjs",
-    "main": "tools/node.js",
-    "version": "2.3",
-    "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": {
-        "async"      : "~0.2.6",
-        "source-map" : "~0.1.7",
-        "optimist"   : "~0.3.5"
-    },
-    "bin": {
-        "uglifyjs" : "bin/uglifyjs"
-    },
-    "scripts": {"test": "node test/run-tests.js"}
+  "name": "uglify-es",
+  "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
+  "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
+  "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
+  "license": "BSD-2-Clause",
+  "version": "3.0.13",
+  "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": {
+    "commander": "~2.9.0",
+    "source-map": "~0.5.1"
+  },
+  "devDependencies": {
+    "acorn": "~5.0.3",
+    "mocha": "~2.3.4",
+    "semver": "~5.3.0"
+  },
+  "scripts": {
+    "test": "node test/run-tests.js"
+  },
+  "keywords": ["uglify", "uglify-js", "uglify-es", "minify", "minifier", "es5", "es6", "es2015"]
 }

test/benchmark.js

@@ -0,0 +1,75 @@
+#! /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");
+}
+args.push("--timings");
+var urls = [
+    "https://code.jquery.com/jquery-3.2.1.js",
+    "https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.6.4/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);
+            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/arrays.js

@@ -1,12 +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 +1,35 @@
+ascii_only_true: {
+    options = {}
+    beautify = {
+        ascii_only : true,
+        ie8        : false,
+        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,
+        ie8        : false,
+        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 +136,882 @@ 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"
+}
+
+delete_conditional_1: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (1 ? undefined : x));
+        console.log(delete (1 ? void 0 : x));
+        console.log(delete (1 ? Infinity : x));
+        console.log(delete (1 ? 1 / 0 : x));
+        console.log(delete (1 ? NaN : x));
+        console.log(delete (1 ? 0 / 0 : x));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}
+
+delete_conditional_2: {
+    options = {
+        booleans: true,
+        conditionals: true,
+        evaluate: true,
+        keep_infinity: true,
+        side_effects: true,
+    }
+    input: {
+        console.log(delete (0 ? x : undefined));
+        console.log(delete (0 ? x : void 0));
+        console.log(delete (0 ? x : Infinity));
+        console.log(delete (0 ? x : 1 / 0));
+        console.log(delete (0 ? x : NaN));
+        console.log(delete (0 ? x : 0 / 0));
+    }
+    expect: {
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+        console.log(!0);
+    }
+    expect_stdout: true
+}

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

@@ -31,7 +31,7 @@ dead_code_2_should_warn: {
         function f() {
             g();
             x = 10;
-            throw "foo";
+            throw new Error("foo");
             // completely discarding the `if` would introduce some
             // bugs.  UglifyJS v1 doesn't deal with this issue; in v2
             // we copy any declarations to the upper scope.
@@ -46,16 +46,60 @@ dead_code_2_should_warn: {
                 })();
             }
         }
+        f();
     }
     expect: {
         function f() {
             g();
             x = 10;
-            throw "foo";
+            throw new Error("foo");
             var x;
-            function g(){};
+            var g;
         }
+        f();
     }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+dead_code_2_should_warn_strict: {
+    options = {
+        dead_code: true
+    };
+    input: {
+        "use strict";
+        function f() {
+            g();
+            x = 10;
+            throw new Error("foo");
+            // completely discarding the `if` would introduce some
+            // bugs.  UglifyJS v1 doesn't deal with this issue; in v2
+            // we copy any declarations to the upper scope.
+            if (x) {
+                y();
+                var x;
+                function g(){};
+                // but nested declarations should not be kept.
+                (function(){
+                    var q;
+                    function y(){};
+                })();
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f() {
+            g();
+            x = 10;
+            throw new Error("foo");
+            var x;
+        }
+        f();
+    }
+    expect_stdout: true
+    node_version: ">=4"
 }
 
 dead_code_constant_boolean_should_warn_more: {
@@ -64,7 +108,8 @@ 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"))) {
@@ -72,18 +117,263 @@ 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;
         }
+        bar();
     }
     expect: {
         var foo;
-        function bar() {}
+        var bar;
         // nothing for the while
         // as for the for, it should keep:
-        var x = 10;
+        var x = 10, y;
         var moo;
+        bar();
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
+
+dead_code_constant_boolean_should_warn_more_strict: {
+    options = {
+        dead_code    : true,
+        loops        : true,
+        booleans     : true,
+        conditionals : true,
+        evaluate     : true,
+        side_effects : true,
+    };
+    input: {
+        "use strict";
+        while (!((foo && bar) || (x + "0"))) {
+            console.log("unreachable");
+            var foo;
+            function bar() {}
+        }
+        for (var x = 10, y; x && (y || x) && (!typeof x); ++x) {
+            asdf();
+            foo();
+            var moo;
+        }
+        bar();
+    }
+    expect: {
+        "use strict";
+        var foo;
+        // nothing for the while
+        // as for the for, it should keep:
+        var x = 10, y;
+        var moo;
+        bar();
+    }
+    expect_stdout: true
+    node_version: ">=4"
+}
+
+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;
+        var 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;
+        var 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;
+        var bar;
+        var beef = 'good';
+        var meat = 'beef';
+        var pork = 'bad';
+    }
+    expect_stdout: true
+}
+
+try_catch_finally: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+    }
+    input: {
+        var a = 1;
+        !function() {
+            try {
+                if (false) throw x;
+            } catch (a) {
+                var a = 2;
+                console.log("FAIL");
+            } finally {
+                a = 3;
+                console.log("PASS");
+            }
+        }();
+        try {
+            console.log(a);
+        } finally {
+        }
+    }
+    expect: {
+        var a = 1;
+        !function() {
+            var a;
+            a = 3;
+            console.log("PASS");
+        }();
+        try {
+            console.log(a);
+        } finally {
+        }
+    }
+    expect_stdout: [
+        "PASS",
+        "1",
+    ]
+}
+
+accessor: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        ({
+            get a() {},
+            set a(v){
+                this.b = 2;
+            },
+            b: 1
+        });
+    }
+    expect: {}
+}

test/compress/destructuring.js

@@ -0,0 +1,545 @@
+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 x = [[1, 2, 3]];
+            var y = {h: 1};
+            var [b, ...c] = a;
+            var [...[e, f]] = x;
+            var [...{g: h}] = y;
+            f(b, c, e, f, g);
+        }
+    }
+    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 x = [[1, 2, 3]];
+            var y = {h: 1};
+            var [b, ...c] = a;
+            var [...[e, f]] = x;
+            var [...{g: h}] = y;
+            f(b, c, e, f, g);
+        }
+    }
+}
+
+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);
+    }
+}
+
+issue_1886: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        let [a] = [1];
+        console.log(a);
+    }
+    expect: {
+        let [a] = [1];
+        console.log(a);
+    }
+}
+
+destructuring_decl_of_numeric_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let { 3: x } = { [1 + 2]: 42 };
+        console.log(x);
+    }
+    expect: {
+        let { 3: x } = { [3]: 42 };
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+destructuring_decl_of_computed_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let four = 4;
+        let { [7 - four]: x } = { [1 + 2]: 42 };
+        console.log(x);
+    }
+    expect: {
+        let four = 4;
+        let { [7 - four]: x } = { [3]: 42 };
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+destructuring_assign_of_numeric_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let x;
+        ({ 3: x } = { [1 + 2]: 42 });
+        console.log(x);
+    }
+    expect: {
+        let x;
+        ({ 3: x } = { [3]: 42 });
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+destructuring_assign_of_computed_key: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    input: {
+        let x;
+        let four = 4;
+        ({ [(5 + 2) - four]: x } = { [1 + 2]: 42 });
+        console.log(x);
+    }
+    expect: {
+        let x;
+        let four = 4;
+        ({ [7 - four]: x } = { [3]: 42 });
+        console.log(x);
+    }
+    expect_stdout: "42"
+    node_version: ">=6"
+}
+
+mangle_destructuring_decl: {
+    options = {
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+    }
+    input: {
+        function test(opts) {
+            let a = opts.a || { e: 7, n: 8 };
+            let { t, e, n, s =  5 + 4, o, r } = a;
+            console.log(t, e, n, s, o, r);
+        }
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function test(t) {
+            let e = t.a || { e: 7, n: 8 };
+            let {t: n,  e: o,  n: s,  s: a = 9,  o: c,  r: l} = e;
+            console.log(n, o, s, a, c, l);
+        }
+        test({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        test({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_assign_toplevel_true: {
+    options = {
+        toplevel: true,
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function test(opts) {
+            let s, o, r;
+            let a = opts.a || { e: 7, n: 8 };
+            ({ t, e, n, s =  5 + 4, o, r } = a);
+            console.log(t, e, n, s, o, r);
+        }
+        let t, e, n;
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function n(n) {
+            let t, a, c;
+            let l = n.a || { e: 7, n: 8 };
+            ({t: o,  e,  n: s,  s: t = 9,  o: a,  r: c} = l);
+            console.log(o, e, s, t, a, c);
+        }
+        let o, e, s;
+        n({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        n({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_assign_toplevel_false: {
+    options = {
+        toplevel: false,
+        evaluate: true,
+        unused: true,
+    }
+    mangle = {
+        toplevel: false,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        function test(opts) {
+            let s, o, r;
+            let a = opts.a || { e: 7, n: 8 };
+            ({ t, e, n, s = 9, o, r } = a);
+            console.log(t, e, n, s, o, r);
+        }
+        let t, e, n;
+        test({a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 }});
+        test({});
+    }
+    expect: {
+        function test(o) {
+            let s, a, c;
+            let l = o.a || { e: 7, n: 8 };
+            ({t,  e,  n,  s = 9,  o: a,  r: c} = l);
+            console.log(t, e, n, s, a, c);
+        }
+        let t, e, n;
+        test({ a: { t: 1, e: 2, n: 3, s: 4, o: 5, r: 6 } });
+        test({});
+    }
+    expect_stdout: [
+        "1 2 3 4 5 6",
+        "undefined 7 8 9 undefined undefined",
+    ]
+    node_version: ">=6"
+}
+
+mangle_destructuring_decl_array: {
+    options = {
+        evaluate: true,
+        unused: true,
+        toplevel: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    beautify = {
+        ecma: 6
+    }
+    input: {
+        var [, t, e, n, s, o = 2, r = [ 1 + 2 ]] = [ 9, 8, 7, 6 ];
+        console.log(t, e, n, s, o, r);
+    }
+    expect: {
+        var [, o,  l,  a,  c,  e = 2,  g = [ 3 ]] = [ 9, 8, 7, 6 ];
+        console.log(o, l, a, c, e, g);
+    }
+    expect_stdout: "8 7 6 undefined 2 [ 3 ]"
+    node_version: ">=6"
+}

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/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 +1,247 @@
+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;
+    }
+}
+
+issue_1841_1: {
+    options = {
+        keep_fargs: false,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var b = 10;
+        !function(arg) {
+            for (var key in "hi")
+                var n = arg.baz, n = [ b = 42 ];
+        }(--b);
+        console.log(b);
+    }
+    expect: {
+        var b = 10;
+        !function() {
+            for (var key in "hi")
+                b = 42;
+        }(--b);
+        console.log(b);
+    }
+    expect_exact: "42"
+}
+
+issue_1841_2: {
+    options = {
+        keep_fargs: false,
+        pure_getters: false,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        var b = 10;
+        !function(arg) {
+            for (var key in "hi")
+                var n = arg.baz, n = [ b = 42 ];
+        }(--b);
+        console.log(b);
+    }
+    expect: {
+        var b = 10;
+        !function(arg) {
+            for (var key in "hi")
+                arg.baz, b = 42;
+        }(--b);
+        console.log(b);
+    }
+    expect_exact: "42"
+}
+
+function_returning_constant_literal: {
+    options = {
+        reduce_vars: true,
+        unsafe: true,
+        toplevel: true,
+        evaluate: true,
+        cascade: true,
+        unused: true,
+    }
+    input: {
+        function greeter() {
+            return { message: 'Hello there' };
+        }
+        var greeting = greeter();
+        console.log(greeting.message);
+    }
+    expect: {
+        console.log("Hello there");
+    }
+    expect_stdout: "Hello there"
+}
+
+hoist_funs: {
+    options = {
+        hoist_funs: true,
+    }
+    input: {
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        function g() {}
+        console.log(6, typeof f, typeof g);
+    }
+    expect: {
+        function g() {}
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        console.log(6, typeof f, typeof g);
+    }
+    expect_stdout: [
+        "1 'undefined' 'function'",
+        "2 'undefined' 'function'",
+        "4 'function' 'function'",
+        "5 'function' 'function'",
+        "6 'function' 'function'",
+    ]
+    node_version: ">=6"
+}
+
+hoist_funs_strict: {
+    options = {
+        hoist_funs: true,
+    }
+    input: {
+        "use strict";
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        function g() {}
+        console.log(6, typeof f, typeof g);
+    }
+    expect: {
+        "use strict";
+        function g() {}
+        console.log(1, typeof f, typeof g);
+        if (console.log(2, typeof f, typeof g))
+            console.log(3, typeof f, typeof g);
+        else {
+            console.log(4, typeof f, typeof g);
+            function f() {}
+            console.log(5, typeof f, typeof g);
+        }
+        console.log(6, typeof f, typeof g);
+    }
+    expect_stdout: [
+        "1 'undefined' 'function'",
+        "2 'undefined' 'function'",
+        "4 'function' 'function'",
+        "5 'function' 'function'",
+        "6 'undefined' 'function'",
+    ]
+    node_version: ">=4"
+}

test/compress/global_defs.js

@@ -0,0 +1,176 @@
+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]',
+    ]
+}
+
+issue_1801: {
+    options = {
+        booleans: true,
+        global_defs: {
+            "CONFIG.FOO.BAR": true,
+        },
+    }
+    input: {
+        console.log(CONFIG.FOO.BAR);
+    }
+    expect: {
+        console.log(!0);
+    }
+}
+
+issue_1986: {
+    options = {
+        global_defs: {
+            "@alert": "console.log",
+        },
+    }
+    input: {
+        alert(42);
+    }
+    expect: {
+        console.log(42);
+    }
+}

test/compress/harmony.js

@@ -0,0 +1,585 @@
+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"(){}}'
+}
+
+classes_with_expression_as_expand: {
+    input: {
+        class D extends (calls++, C) {}
+    }
+    expect_exact: "class D extends(calls++,C){}"
+}
+
+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";'
+}
+
+import_all_statement: {
+    input: {
+        import * from 'lel';
+        import * as Lel from 'lel';
+    }
+    expect_exact: 'import*from"lel";import*as Lel from"lel";'
+}
+
+export_statement: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default 1 + 2;
+        export var foo = 4;
+        export let foo = 6;
+        export const foo = 6;
+        export function foo() {};
+        export class foo { };
+    }
+    expect_exact: "export default 3;export var foo=4;export let foo=6;export const foo=6;export function foo(){};export class foo{};"
+}
+
+export_default_object_expression: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default {
+            foo: 1 + 2,
+            bar() { return 4; },
+            get baz() { return this.foo; },
+        };
+    }
+    expect_exact: "export default{foo:3,bar(){return 4},get baz(){return this.foo}};"
+}
+
+export_default_array: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default [ 1 + 2, foo ];
+    }
+    expect_exact: "export default[3,foo];"
+}
+
+export_default_anon_function: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default function(){
+            console.log(1 + 2);
+        }
+    }
+    expect_exact: "export default function(){console.log(3)};"
+}
+
+export_default_anon_class: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        export default class {
+            foo() { console.log(1 + 2); }
+        }
+    }
+    expect_exact: "export default class{foo(){console.log(3)}};"
+}
+
+export_module_statement: {
+    input: {
+        export * from "a.js";
+        export {A} from "a.js";
+        export {A, B} from "a.js";
+        export {C};
+    }
+    expect_exact: 'export*from"a.js";export{A}from"a.js";export{A,B}from"a.js";export{C};'
+}
+
+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);
+        }
+
+        g = ([[] = 123]) => {};
+        h = ([[x, y, z] = [4, 5, 6]] = []) => {};
+
+        function i([[x, y, z] = [4, 5, 6]] = []) {
+            console.log(b);
+        };
+    }
+    expect: {
+        function f(a) {
+            console.log(a);
+        }
+
+        g = ([[] = 123]) => {};
+        h = ([[x, y, z] = [4, 5, 6]] = []) => {};
+
+        function i([[x, y, z] = [4, 5, 6]] = []) {
+            console.log(b);
+        };
+    }
+}
+
+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};"
+}
+
+format_methods: {
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        class A extends B {constructor(a){x()} static s(b,c){y()} run(d,e,f){z()}}
+    }
+    expect_exact: [
+        "class A extends B {",
+        "    constructor(a) {",
+        "        x();",
+        "    }",
+        "    static s(b, c) {",
+        "        y();",
+        "    }",
+        "    run(d, e, f) {",
+        "        z();",
+        "    }",
+        "}",
+    ]
+}
+
+issue_1898: {
+    options = {
+    }
+    mangle = {
+    }
+    input: {
+        class Foo {
+            bar() {
+                for (const x of [ 6, 5 ]) {
+                    for (let y of [ 4, 3 ]) {
+                        for (var z of [ 2, 1 ]) {
+                            console.log(x, y, z);
+                        }
+                    }
+                }
+            }
+        }
+        new Foo().bar();
+    }
+    expect: {
+        class Foo {
+            bar() {
+                for (const n of [ 6, 5 ])
+                    for (let r of [ 4, 3 ])
+                        for (var o of [ 2, 1 ])
+                            console.log(n, r, o);
+            }
+        }
+        new Foo().bar();
+    }
+}
+
+issue_1753: {
+    mangle = { safari10: true };
+    input: {
+        class SomeClass {
+            constructor(props) {
+                let pickedSets = [];
+                for (let i = 0; i < 6; i++) {
+                    pickedSets.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+                }
+            }
+        }
+    }
+    expect: {
+        class SomeClass {
+            constructor(r) {
+                let a = [];
+                for (let s = 0; s < 6; s++)
+                    a.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+            }
+        }
+    }
+}
+
+issue_1753_disable: {
+    mangle = { safari10: false }
+    input: {
+        class SomeClass {
+            constructor(props) {
+                let pickedSets = [];
+                for (let i = 0; i < 6; i++) {
+                    pickedSets.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+                }
+            }
+        }
+    }
+    expect: {
+        class SomeClass {
+            constructor(r) {
+                let a = [];
+                for (let r = 0; r < 6; r++)
+                    a.push({
+                        mainDrawNumbers: [],
+                        extraDrawNumbers: []
+                    });
+            }
+        }
+    }
+}
+
+class_extends: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        function f() {
+            class foo extends bar {}
+            class pro extends some.prop {}
+            class arr extends stuff[1 - 1] {}
+            class bin extends (a || b) {}
+            class seq extends (a, b) {}
+            class ter extends (a ? b : c) {}
+            class uni extends (!0) {}
+        }
+    }
+    expect_exact: "function f(){class foo extends bar{}class pro extends some.prop{}class arr extends stuff[0]{}class bin extends(a||b){}class seq extends(a,b){}class ter extends(a?b:c){}class uni extends(!0){}}"
+}
+
+class_extends_class: {
+    options = {
+    }
+    input: {
+        class anon extends class {} {}
+        class named extends class base {} {}
+    }
+    expect_exact: "class anon extends class{}{}class named extends class base{}{}"
+}
+
+class_extends_function: {
+    options = {
+    }
+    input: {
+        class anon extends function(){} {}
+        class named extends function base(){} {}
+    }
+    expect_exact: "class anon extends function(){}{}class named extends function base(){}{}"
+}
+
+class_extends_regex: {
+    options = {
+    }
+    input: {
+        function f() {
+            class rx1 extends (/rx/) {}
+            // class rx2 extends /rx/ {}  // FIXME - parse error
+        }
+    }
+    expect_exact: "function f(){class rx1 extends(/rx/){}}"
+}

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 +1,386 @@
+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);
+        }
+    }
+}
+
+issue_512: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        function a() {
+            if (b()) {
+                c();
+                return;
+            }
+            throw e;
+        }
+    }
+    expect: {
+        function a() {
+            if (!b()) throw e;
+            c();
+        }
+    }
+}
+
+issue_1317: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect: {
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect_stdout: "1"
+    node_version: ">=6"
+}
+
+issue_1317_strict: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect: {
+        "use strict";
+        !function(a) {
+            if (a) return;
+            let b = 1;
+            function g() {
+                return b;
+            }
+            console.log(g());
+        }();
+    }
+    expect_stdout: "1"
+    node_version: ">=4"
+}

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 +1,252 @@
+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]",
+    ]
+}
+
+non_hoisted_function_after_return_strict: {
+    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: {
+        "use strict";
+        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; }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect: {
+        "use strict";
+        function foo(x) {
+            return x ? bar() : baz();
+            function bar() { return 7 }
+            function baz() { return 8 }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect_stdout: "8 7"
+    expect_warnings: [
+        'WARN: Dropping unreachable code [test/compress/issue-1034.js:131,16]',
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:134,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:137,12]",
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:138,21]"
+    ]
+}
+
+non_hoisted_function_after_return_2a_strict: {
+    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: {
+        "use strict";
+        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;
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect: {
+        "use strict";
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) {
+                return 7 - x;
+            }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect_stdout: "5 6"
+    expect_warnings: [
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:173,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:173,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:176,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:176,16]",
+        "WARN: Dropping unused variable a [test/compress/issue-1034.js:173,20]",
+        "WARN: Dropping unused function nope [test/compress/issue-1034.js:180,21]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:178,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:178,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:181,12]",
+        "WARN: Dropping unused variable b [test/compress/issue-1034.js:176,20]",
+        "WARN: Dropping unused variable c [test/compress/issue-1034.js:178,16]",
+    ]
+}
+
+non_hoisted_function_after_return_2b_strict: {
+    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: {
+        "use strict";
+        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;
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect: {
+        "use strict";
+        function foo(x) {
+            return bar(x ? 1 : 2);
+            function bar(x) { return 7 - x; }
+        }
+        console.log(foo(0), foo(1));
+    }
+    expect_stdout: "5 6"
+    expect_warnings: [
+        // duplicate warnings no longer emitted
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:225,16]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:225,16]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:227,12]",
+        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:227,12]",
+        "WARN: Dropping unreachable code [test/compress/issue-1034.js:231,12]",
+    ]
+}

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-105.js

@@ -1,17 +0,0 @@
-typeof_eq_undefined: {
-    options = {
-        comparisons: true,
-        unsafe: false
-    };
-    input: { a = typeof b.c != "undefined" }
-    expect: { a = "undefined" != typeof b.c }
-}
-
-typeof_eq_undefined_unsafe: {
-    options = {
-        comparisons: true,
-        unsafe: true
-    };
-    input: { a = typeof b.c != "undefined" }
-    expect: { a = b.c !== void 0 }
-}

test/compress/issue-1052.js

@@ -0,0 +1,163 @@
+multiple_functions: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+            function f() {}
+            function g() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            // NOTE: other compression steps will reduce this
+            // down to just `window`.
+            if ( window );
+            function f() {}
+            function g() {}
+        } )();
+    }
+}
+
+single_function: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+            function f() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            if ( window );
+            function f() {}
+        } )();
+    }
+}
+
+deeply_nested: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+            function f() {}
+            function g() {}
+            if ( !document ) {
+                return;
+            }
+            function h() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            // NOTE: other compression steps will reduce this
+            // down to just `window`.
+            if ( window )
+                if (document);
+            function f() {}
+            function g() {}
+            function h() {}
+        } )();
+    }
+}
+
+not_hoisted_when_already_nested: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        ( function() {
+            if ( !window ) {
+                return;
+            }
+            if ( foo ) function f() {}
+        } )();
+    }
+    expect: {
+        ( function() {
+            if ( window )
+                if ( foo ) function f() {}
+        } )();
+    }
+}
+
+defun_if_return: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        function e() {
+            function f() {}
+            if (!window) return;
+            else function g() {}
+            function h() {}
+        }
+    }
+    expect: {
+        function e() {
+            function f() {}
+            if (window) function g() {}
+            function h() {}
+        }
+    }
+}
+
+defun_hoist_funs: {
+    options = {
+        hoist_funs: true,
+        if_return: true,
+    }
+    input: {
+        function e() {
+            function f() {}
+            if (!window) return;
+            else function g() {}
+            function h() {}
+        }
+    }
+    expect: {
+        function e() {
+            function f() {}
+            function h() {}
+            if (window) function g() {}
+        }
+    }
+}
+
+defun_else_if_return: {
+    options = {
+        hoist_funs: false,
+        if_return: true,
+    }
+    input: {
+        function e() {
+            function f() {}
+            if (window) function g() {}
+            else return;
+            function h() {}
+        }
+    }
+    expect: {
+        function e() {
+            function f() {}
+            if (window) function g() {}
+            function h() {}
+        }
+    }
+}

test/compress/issue-1105.js

@@ -0,0 +1,305 @@
+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,
+        keep_infinity: false,
+    }
+    input: {
+        var f = console.log;
+        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 f = console.log, 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);
+        }
+    }
+    expect_stdout: true
+}
+
+assorted_Infinity_NaN_undefined_in_with_scope_keep_infinity: {
+    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,
+        keep_infinity: true,
+    }
+    input: {
+        var f = console.log;
+        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 f = console.log, o = {
+            undefined : 3,
+            NaN       : 4,
+            Infinity  : 5
+        };
+        if (o) {
+            f(void 0, void 0);
+            f(NaN, NaN);
+            f(Infinity, 1/0);
+            f(-Infinity, -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);
+        }
+    }
+    expect_stdout: true
+}

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: Condition left of || 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: Condition left of && 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 = {
+        keep_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 = {
+        keep_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 = {
+        keep_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,
+        ie8: 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 = "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 = {
+        ie8: false,
+    }
+    mangle = {
+        ie8: false,
+    }
+    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 = {
+        ie8: true,
+    }
+    mangle = {
+        ie8: true,
+    }
+    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 +1,52 @@
+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() {
+                f(1).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() {
+            (function() {
+                var b = "long piece of string";
+                f(b).bar = b;
+            })();
+        })();
+    }
+}

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 b = 10;",
+        "",
+        "!function() {",
+        "    for (;b = 100, !1; ) ;",
+        "}(), console.log(100, b);",
+    ]
+    expect_stdout: true
+}

test/compress/issue-1673.js

@@ -0,0 +1,161 @@
+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 {
+                    x();
+                } catch (e) {
+                } finally {
+                    console.log("PASS");
+                }
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            (function() {
+                try {
+                    x();
+                } 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 = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        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(o){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        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(args){a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        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(o){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_var_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        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(args){var a="PASS"}console.log(a);'
+    expect_stdout: "PASS"
+}
+
+mangle_catch_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        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_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        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_var_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        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_var_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        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_redef_1: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        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_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        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_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        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_1_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        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_2: {
+    options = {
+        ie8: false,
+        toplevel: false,
+    }
+    mangle = {
+        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_ie8: {
+    options = {
+        ie8: true,
+        toplevel: false,
+    }
+    mangle = {
+        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_toplevel: {
+    options = {
+        ie8: false,
+        toplevel: true,
+    }
+    mangle = {
+        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"
+}
+
+mangle_catch_redef_2_ie8_toplevel: {
+    options = {
+        ie8: true,
+        toplevel: true,
+    }
+    mangle = {
+        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"
+}

test/compress/issue-1733.js

@@ -0,0 +1,97 @@
+function_iife_catch: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        function f(n) {
+            !function() {
+                try {
+                    throw 0;
+                } catch (n) {
+                    var a = 1;
+                    console.log(n, a);
+                }
+            }();
+        }
+        f();
+    }
+    expect_exact: "function f(o){!function(){try{throw 0}catch(c){var o=1;console.log(c,o)}}()}f();"
+    expect_stdout: "0 1"
+}
+
+function_iife_catch_ie8: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        function f(n) {
+            !function() {
+                try {
+                    throw 0;
+                } catch (n) {
+                    var a = 1;
+                    console.log(n, a);
+                }
+            }();
+        }
+        f();
+    }
+    expect_exact: "function f(o){!function(){try{throw 0}catch(o){var c=1;console.log(o,c)}}()}f();"
+    expect_stdout: "0 1"
+}
+
+function_catch_catch: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        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(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_stdout: [
+        "3",
+        "undefined",
+    ]
+}
+
+function_catch_catch_ie8: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        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(c){try{throw 2}catch(o){var o=3;console.log(o)}}console.log(o)}f();"
+    expect_stdout: [
+        "3",
+        "undefined",
+    ]
+}

test/compress/issue-1750.js

@@ -0,0 +1,54 @@
+case_1: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a = 0, b = 1;
+        switch (true) {
+          case a, true:
+          default:
+            b = 2;
+          case true:
+        }
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 1;
+        switch (true) {
+          case a, true:
+            b = 2;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "0 2"
+}
+
+case_2: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a = 0, b = 1;
+        switch (0) {
+          default:
+            b = 2;
+          case a:
+            a = 3;
+          case 0:
+        }
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 1;
+        switch (0) {
+          case a:
+            a = 3;
+        }
+        console.log(a, b);
+    }
+    expect_stdout: "3 1"
+}

test/compress/issue-1770.js

@@ -0,0 +1,105 @@
+mangle_props: {
+    mangle_props = {}
+    input: {
+        var obj = {
+            undefined: 1,
+            NaN: 2,
+            Infinity: 3,
+            "-Infinity": 4,
+            null: 5,
+        };
+        console.log(
+            obj[void 0],
+            obj[undefined],
+            obj["undefined"],
+            obj[0/0],
+            obj[NaN],
+            obj["NaN"],
+            obj[1/0],
+            obj[Infinity],
+            obj["Infinity"],
+            obj[-1/0],
+            obj[-Infinity],
+            obj["-Infinity"],
+            obj[null],
+            obj["null"]
+        );
+    }
+    expect: {
+        var obj = {
+            undefined: 1,
+            NaN: 2,
+            Infinity: 3,
+            "-Infinity": 4,
+            null: 5,
+        };
+        console.log(
+            obj[void 0],
+            obj[void 0],
+            obj["undefined"],
+            obj[0/0],
+            obj[NaN],
+            obj["NaN"],
+            obj[1/0],
+            obj[1/0],
+            obj["Infinity"],
+            obj[-1/0],
+            obj[-1/0],
+            obj["-Infinity"],
+            obj[null],
+            obj["null"]
+        );
+    }
+    expect_stdout: "1 1 1 2 2 2 3 3 3 4 4 4 5 5"
+}
+
+numeric_literal: {
+    beautify = {
+        beautify: true,
+    }
+    mangle_props = {}
+    input: {
+        var obj = {
+            0: 0,
+            "-0": 1,
+            42: 2,
+            "42": 3,
+            0x25: 4,
+            "0x25": 5,
+            1E42: 6,
+            "1E42": 7,
+            "1e+42": 8,
+        };
+        console.log(obj[-0], obj[-""], obj["-0"]);
+        console.log(obj[42], obj["42"]);
+        console.log(obj[0x25], obj["0x25"], obj[37], obj["37"]);
+        console.log(obj[1E42], obj["1E42"], obj["1e+42"]);
+    }
+    expect_exact: [
+        'var obj = {',
+        '    0: 0,',
+        '    "-0": 1,',
+        '    42: 2,',
+        '    "42": 3,',
+        '    37: 4,',
+        '    a: 5,',
+        '    1e42: 6,',
+        '    b: 7,',
+        '    "1e+42": 8',
+        '};',
+        '',
+        'console.log(obj[-0], obj[-""], obj["-0"]);',
+        '',
+        'console.log(obj[42], obj["42"]);',
+        '',
+        'console.log(obj[37], obj["a"], obj[37], obj["37"]);',
+        '',
+        'console.log(obj[1e42], obj["b"], obj["1e+42"]);',
+    ]
+    expect_stdout: [
+        "0 0 1",
+        "3 3",
+        "4 5 4 4",
+        "8 7 8",
+    ]
+}

test/compress/issue-1787.js

@@ -0,0 +1,15 @@
+unary_prefix: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            var x = -(2 / 3);
+            return x;
+        }());
+    }
+    expect_exact: "console.log(-2/3);"
+    expect_stdout: true
+}

test/compress/issue-1833.js

@@ -0,0 +1,134 @@
+iife_for: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: for (;;) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: for (;;) break L;
+            }();
+        }();
+    }
+}
+
+iife_for_in: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: for (var a in x) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: for (var a in x) break L;
+            }();
+        }();
+    }
+}
+
+iife_do: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: do {
+                    break L;
+                } while (1);
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: do {
+                    break L;
+                } while (1);
+            }();
+        }();
+    }
+}
+
+iife_while: {
+    options = {
+        negate_iife: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {
+                L: while (1) break L;
+            }
+            g();
+        }
+        f();
+    }
+    expect: {
+        !function() {
+            !function() {
+                L: while (1) break L;
+            }();
+        }();
+    }
+}
+
+label_do: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        L: do {
+            continue L;
+        } while (0);
+    }
+    expect: {
+        L: do {
+            continue L;
+        } while (0);
+    }
+}
+
+label_while: {
+    options = {
+        evaluate: true,
+        dead_code: true,
+        loops: true,
+    }
+    input: {
+        function f() {
+            L: while (0) continue L;
+        }
+    }
+    expect_exact: "function f(){L:;}"
+}

test/compress/issue-1943.js

@@ -0,0 +1,31 @@
+operator: {
+    input: {
+        a. //comment
+        typeof
+    }
+    expect_exact: "a.typeof;"
+}
+
+name: {
+    input: {
+        a. //comment
+        b
+    }
+    expect_exact: "a.b;"
+}
+
+keyword: {
+    input: {
+        a. //comment
+        default
+    }
+    expect_exact: "a.default;"
+}
+
+atom: {
+    input: {
+        a. //comment
+        true
+    }
+    expect_exact: "a.true;"
+}

test/compress/issue-2001.js

@@ -0,0 +1,281 @@
+export_func_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f(){};
+    }
+    expect_exact: "export function f(){};"
+}
+
+export_func_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f(){}(1);
+    }
+    expect_exact: "export function f(){};1;"
+}
+
+export_func_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export function f(){}(1);
+    }
+    expect_exact: "export function f(){};"
+}
+
+export_default_func_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){};
+    }
+    expect_exact: "export default function(){};"
+}
+
+export_default_func_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){}(1);
+    }
+    expect_exact: "export default function(){};1;"
+}
+
+export_default_func_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){}(1);
+    }
+    expect_exact: "export default function(){};"
+}
+
+export_class_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class C {};
+    }
+    expect_exact: "export class C{};"
+}
+
+export_class_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class C {}(1);
+    }
+    expect_exact: "export class C{};1;"
+}
+
+export_class_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export class C {}(1);
+    }
+    expect_exact: "export class C{};"
+}
+
+export_default_class_1: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class C {};
+    }
+    expect_exact: "export default class{};"
+}
+
+export_default_class_2: {
+    options = {
+        hoist_funs: true,
+        side_effects: false,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class C {}(1);
+    }
+    expect_exact: "export default class{};1;"
+}
+
+export_default_class_3: {
+    options = {
+        hoist_funs: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default class C {}(1);
+    }
+    expect_exact: "export default class{};"
+}
+
+export_mangle_1: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export function foo(one, two) {
+            return one - two;
+        };
+    }
+    expect_exact: "export function foo(n,o){return n-o};"
+}
+
+export_mangle_2: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default function foo(one, two) {
+            return one - two;
+        };
+    }
+    expect_exact: "export default function n(n,r){return n-r};"
+}
+
+export_mangle_3: {
+    options = {
+        collapse_vars: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export class C {
+            go(one, two) {
+                var z = one;
+                return one - two + z;
+            }
+        };
+    }
+    expect_exact: "export class C{go(n,r){return n-r+n}};"
+}
+
+export_mangle_4: {
+    options = {
+        collapse_vars: true,
+    }
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default class C {
+            go(one, two) {
+                var z = one;
+                return one - two + z;
+            }
+        };
+    }
+    expect_exact: "export default class n{go(n,r){return n-r+n}};"
+}
+
+export_mangle_5: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        export default {
+            prop: function(one, two) {
+                return one - two;
+            }
+        };
+    }
+    expect_exact: "export default{prop:function(n,r){return n-r}};"
+}
+
+export_mangle_6: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        var baz = 2;
+        export let foo = 1, bar = baz;
+    }
+    expect_exact: "var a=2;export let foo=1,bar=a;"
+}
+
+export_toplevel_1: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f(){}
+        export function g(){};
+        export default function h(){};
+    }
+    expect: {
+        export function g(){};
+        export default function(){};
+    }
+}
+
+export_toplevel_2: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        class A {}
+        export class B {};
+        export default class C {};
+    }
+    expect: {
+        export class B {};
+        export default class {};
+    }
+}
+
+export_default_func_ref: {
+    options = {
+        hoist_funs: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        export default function f(){};
+        f();
+    }
+    expect_exact: "export default function f(){};f();"
+}

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-597.js

@@ -0,0 +1,157 @@
+NaN_and_Infinity_must_have_parens: {
+    options = {};
+    input: {
+        Infinity.toString();
+        NaN.toString();
+    }
+    expect: {
+        (1/0).toString();
+        NaN.toString();
+    }
+}
+
+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();
+    }
+}
+
+NaN_and_Infinity_must_have_parens_evaluate: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        (123456789 / 0).toString();
+        (+"foo").toString();
+    }
+    expect: {
+        (1/0).toString();
+        NaN.toString();
+    }
+}
+
+NaN_and_Infinity_should_not_be_replaced_when_they_are_redefined_evaluate: {
+    options = {
+        evaluate: true,
+    }
+    input: {
+        var Infinity, NaN;
+        (123456789 / 0).toString();
+        (+"foo").toString();
+    }
+    expect: {
+        var Infinity, NaN;
+        (1/0).toString();
+        (0/0).toString();
+    }
+}
+
+beautify_off_1: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: false,
+    }
+    input: {
+        var NaN;
+        console.log(
+            null,
+            undefined,
+            Infinity,
+            NaN,
+            Infinity * undefined,
+            Infinity.toString(),
+            NaN.toString(),
+            (Infinity * undefined).toString()
+        );
+    }
+    expect_exact: "var NaN;console.log(null,void 0,1/0,NaN,0/0,(1/0).toString(),NaN.toString(),(0/0).toString());"
+    expect_stdout: true
+}
+
+beautify_off_2: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: false,
+    }
+    input: {
+        console.log(
+            null.toString(),
+            undefined.toString()
+        );
+    }
+    expect_exact: "console.log(null.toString(),(void 0).toString());"
+}
+
+beautify_on_1: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        var NaN;
+        console.log(
+            null,
+            undefined,
+            Infinity,
+            NaN,
+            Infinity * undefined,
+            Infinity.toString(),
+            NaN.toString(),
+            (Infinity * undefined).toString()
+        );
+    }
+    expect_exact: [
+        "var NaN;",
+        "",
+        "console.log(null, void 0, 1 / 0, NaN, 0 / 0, (1 / 0).toString(), NaN.toString(), (0 / 0).toString());",
+    ]
+    expect_stdout: true
+}
+
+beautify_on_2: {
+    options = {
+        evaluate: true,
+    }
+    beautify = {
+        beautify: true,
+    }
+    input: {
+        console.log(
+            null.toString(),
+            undefined.toString()
+        );
+    }
+    expect_exact: "console.log(null.toString(), (void 0).toString());"
+}
+
+issue_1724: {
+    input: {
+        var a = 0;
+        ++a % Infinity | Infinity ? a++ : 0;
+        console.log(a);
+    }
+    expect_exact: "var a=0;++a%(1/0)|1/0?a++:0;console.log(a);"
+    expect_stdout: "2"
+}
+
+issue_1725: {
+    input: {
+        ([].length === 0) % Infinity ? console.log("PASS") : console.log("FAIL");
+    }
+    expect_exact: '(0===[].length)%(1/0)?console.log("PASS"):console.log("FAIL");'
+    expect_stdout: "PASS"
+}

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(false) : console.log(true), 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 }() ? bar(false) : foo(true), 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 }() ? bar(false) : foo(true), 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';
+    }
+}