v2.4.5

for now only used for keys passed to `-c` or `-b`.

README.md

@@ -87,6 +87,10 @@ The available options are:
                      Note that currently not *all* comments can be kept when
                      compression is on, because of dead code removal or
                      cascading statements into sequences.               [string]
+  --preamble         Preamble to prepend to the output.  You can use this to
+                     insert a comment, for example for licensing information.
+                     This will not be parsed, but the source map will adjust
+                     for its presence.
   --stats            Display operations run time on STDERR.            [boolean]
   --acorn            Use Acorn for parsing.                            [boolean]
   --spidermonkey     Assume input files are SpiderMonkey AST format (as JSON).
@@ -257,7 +261,7 @@ when this flag is on:
 - `String(exp)` or `exp.toString()` → `"" + exp`
 - `new Object/RegExp/Function/Error/Array (...)` → we discard the `new`
 - `typeof foo == "undefined"` → `foo === void 0`
-- `void 0` → `"undefined"` (if there is a variable named "undefined" in
+- `void 0` → `undefined` (if there is a variable named "undefined" in
   scope; we do it because the variable name will be mangled, typically
   reduced to a single character).
 
@@ -328,6 +332,10 @@ can pass additional arguments that control the code output:
   you pass `false` then whenever possible we will use a newline instead of a
   semicolon, leading to more readable output of uglified code (size before
   gzip could be smaller; size after gzip insignificantly larger).
+- `preamble` (default `null`) -- when passed it must be a string and
+  it will be prepended to the output literally.  The source map will
+  adjust for this text.  Can be used to insert a comment containing
+  licensing information, for example.
 
 ### Keeping copyright notices or other comments
 

bin/uglifyjs

@@ -48,6 +48,10 @@ You can optionally pass one of the following arguments to this flag:\n\
 Note that currently not *all* comments can be kept when compression is on, \
 because of dead code removal or cascading statements into sequences.")
 
+    .describe("preamble", "Preamble to prepend to the output.  You can use this to insert a \
+comment, for example for licensing information.  This will not be \
+parsed, but the source map will adjust for its presence.")
+
     .describe("stats", "Display operations run time on STDERR.")
     .describe("acorn", "Use Acorn for parsing.")
     .describe("spidermonkey", "Assume input files are SpiderMonkey AST format (as JSON).")
@@ -58,6 +62,7 @@ You need to pass an argument to this option to specify the name that your module
     .describe("lint", "Display some scope warnings")
     .describe("v", "Verbose")
     .describe("V", "Print version number and exit.")
+    .describe("noerr", "Don't throw an error for unknown options in -c, -b or -m.")
 
     .alias("p", "prefix")
     .alias("o", "output")
@@ -92,6 +97,7 @@ You need to pass an argument to this option to specify the name that your module
     .boolean("spidermonkey")
     .boolean("lint")
     .boolean("V")
+    .boolean("noerr")
 
     .wrap(80)
 
@@ -100,6 +106,12 @@ You need to pass an argument to this option to specify the name that your module
 
 normalize(ARGS);
 
+if (ARGS.noerr) {
+    UglifyJS.DefaultsError.croak = function(msg, defs) {
+        sys.error("WARN: " + msg);
+    };
+}
+
 if (ARGS.version || ARGS.V) {
     var json = require("../package.json");
     sys.puts(json.name + ' ' + json.version);
@@ -134,7 +146,8 @@ if (ARGS.r) {
 }
 
 var OUTPUT_OPTIONS = {
-    beautify: BEAUTIFY ? true : false
+    beautify: BEAUTIFY ? true : false,
+    preamble: ARGS.preamble || null,
 };
 
 if (ARGS.screw_ie8) {
@@ -251,7 +264,6 @@ async.eachLimit(files, 1, function (file, cb) {
             else if (ARGS.acorn) {
                 TOPLEVEL = acorn.parse(code, {
                     locations     : true,
-                    trackComments : true,
                     sourceFile    : file,
                     program       : TOPLEVEL
                 });
@@ -377,7 +389,7 @@ function getOptions(x, constants) {
     if (x !== true) {
         var ast;
         try {
-            ast = UglifyJS.parse(x);
+            ast = UglifyJS.parse(x, { expression: true });
         } catch(ex) {
             if (ex instanceof UglifyJS.JS_Parse_Error) {
                 sys.error("Error parsing arguments in: " + x);
@@ -385,8 +397,6 @@ function getOptions(x, constants) {
             }
         }
         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, "_");
@@ -396,6 +406,11 @@ function getOptions(x, constants) {
                 ret[name] = value;
                 return true;    // no descend
             }
+            if (node instanceof UglifyJS.AST_Symbol || node instanceof UglifyJS.AST_Binary) {
+                var name = node.print_to_string({ beautify: false }).replace(/-/g, "_");
+                ret[name] = true;
+                return true;    // no descend
+            }
             sys.error(node.TYPE)
             sys.error("Error parsing arguments in: " + x);
             process.exit(1);

lib/ast.js

@@ -371,7 +371,7 @@ var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments", {
 }, 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, {
@@ -756,7 +756,7 @@ 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",
+        key: "[string] the property name converted to a string for ObjectKeyVal.  For setters and getters this is an arbitrary AST_Node.",
         value: "[AST_Node] property value.  For setters and getters this is an AST_Function."
     },
     _walk: function(visitor) {

lib/compress.js

@@ -85,14 +85,16 @@ merge(Compressor.prototype, {
     },
     before: function(node, descend, in_list) {
         if (node._squeezed) return node;
+        var was_scope = false;
         if (node instanceof AST_Scope) {
-            node.drop_unused(this);
             node = node.hoist_declarations(this);
+            was_scope = true;
         }
         descend(node, this);
         node = node.optimize(this);
-        if (node instanceof AST_Scope) {
+        if (was_scope && node instanceof AST_Scope) {
             node.drop_unused(this);
+            descend(node, this);
         }
         node._squeezed = true;
         return node;
@@ -1082,18 +1084,23 @@ merge(Compressor.prototype, {
                         }
                         return node;
                     }
-                    if (node instanceof AST_For && node.init instanceof AST_BlockStatement) {
+                    if (node instanceof AST_For) {
                         descend(node, this);
-                        // certain combination of unused name + side effect leads to:
-                        //    https://github.com/mishoo/UglifyJS2/issues/44
-                        // that's an invalid AST.
-                        // We fix it at this stage by moving the `var` outside the `for`.
-                        var body = node.init.body.slice(0, -1);
-                        node.init = node.init.body.slice(-1)[0].body;
-                        body.push(node);
-                        return in_list ? MAP.splice(body) : make_node(AST_BlockStatement, node, {
-                            body: body
-                        });
+
+                        if (node.init instanceof AST_BlockStatement) {
+                            // certain combination of unused name + side effect leads to:
+                            //    https://github.com/mishoo/UglifyJS2/issues/44
+                            // that's an invalid AST.
+                            // We fix it at this stage by moving the `var` outside the `for`.
+
+                            var body = node.init.body.slice(0, -1);
+                            node.init = node.init.body.slice(-1)[0].body;
+                            body.push(node);
+
+                            return in_list ? MAP.splice(body) : make_node(AST_BlockStatement, node, {
+                                body: body
+                            });
+                        }
                     }
                     if (node instanceof AST_Scope && node !== self)
                         return node;
@@ -1614,7 +1621,7 @@ merge(Compressor.prototype, {
                     if (self.args.length != 1) {
                         return make_node(AST_Array, self, {
                             elements: self.args
-                        });
+                        }).transform(compressor);
                     }
                     break;
                   case "Object":
@@ -1628,11 +1635,30 @@ merge(Compressor.prototype, {
                     if (self.args.length == 0) return make_node(AST_String, self, {
                         value: ""
                     });
-                    return make_node(AST_Binary, self, {
+                    if (self.args.length <= 1) return make_node(AST_Binary, self, {
                         left: self.args[0],
                         operator: "+",
                         right: make_node(AST_String, self, { value: "" })
+                    }).transform(compressor);
+                    break;
+                  case "Number":
+                    if (self.args.length == 0) return make_node(AST_Number, self, {
+                        value: 0
                     });
+                    if (self.args.length == 1) return make_node(AST_UnaryPrefix, self, {
+                        expression: self.args[0],
+                        operator: "+"
+                    }).transform(compressor);
+                  case "Boolean":
+                    if (self.args.length == 0) return make_node(AST_False, self);
+                    if (self.args.length == 1) return make_node(AST_UnaryPrefix, self, {
+                        expression: make_node(AST_UnaryPrefix, null, {
+                            expression: self.args[0],
+                            operator: "!"
+                        }),
+                        operator: "!"
+                    }).transform(compressor);
+                    break;
                   case "Function":
                     if (all(self.args, function(x){ return x instanceof AST_String })) {
                         // quite a corner-case, but we can handle it:
@@ -1840,6 +1866,14 @@ merge(Compressor.prototype, {
         return self.evaluate(compressor)[0];
     });
 
+    function has_side_effects_or_prop_access(node, compressor) {
+        var save_pure_getters = compressor.option("pure_getters");
+        compressor.options.pure_getters = false;
+        var ret = node.has_side_effects(compressor);
+        compressor.options.pure_getters = save_pure_getters;
+        return ret;
+    }
+
     AST_Binary.DEFMETHOD("lift_sequences", function(compressor){
         if (compressor.option("sequences")) {
             if (this.left instanceof AST_Seq) {
@@ -1851,8 +1885,8 @@ merge(Compressor.prototype, {
                 return seq;
             }
             if (this.right instanceof AST_Seq
-                && !(this.operator == "||" || this.operator == "&&")
-                && !this.left.has_side_effects(compressor)) {
+                && this instanceof AST_Assign
+                && !has_side_effects_or_prop_access(this.left, compressor)) {
                 var seq = this.right;
                 var x = seq.to_array();
                 this.right = x.pop();
@@ -1882,7 +1916,11 @@ merge(Compressor.prototype, {
                 // if right is a constant, whatever side effects the
                 // left side might have could not influence the
                 // result.  hence, force switch.
-                reverse(null, true);
+
+                if (!(self.left instanceof AST_Binary
+                      && PRECEDENCE[self.left.operator] >= PRECEDENCE[self.operator])) {
+                    reverse(null, true);
+                }
             }
             if (/^[!=]==?$/.test(self.operator)) {
                 if (self.left instanceof AST_SymbolRef && self.right instanceof AST_Conditional) {
@@ -2032,7 +2070,8 @@ merge(Compressor.prototype, {
                     && self.left.right instanceof AST_Constant
                     && self.right instanceof AST_Binary
                     && self.right.operator == "+"
-                    && self.right.left instanceof AST_Constant) {
+                    && self.right.left instanceof AST_Constant
+                    && self.right.is_string(compressor)) {
                     self = make_node(AST_Binary, self, {
                         operator: "+",
                         left: make_node(AST_Binary, self.left, {
@@ -2049,6 +2088,19 @@ merge(Compressor.prototype, {
                 }
             }
         }
+        // x * (y * z)  ==>  x * y * z
+        if (self.right instanceof AST_Binary
+            && self.right.operator == self.operator
+            && (self.operator == "*" || self.operator == "&&" || self.operator == "||"))
+        {
+            self.left = make_node(AST_Binary, self.left, {
+                operator : self.operator,
+                left     : self.left,
+                right    : self.right.left
+            });
+            self.right = self.right.right;
+            return self.transform(compressor);
+        }
         return self.evaluate(compressor)[0];
     });
 

lib/output.js

@@ -61,6 +61,7 @@ function OutputStream(options) {
         comments      : false,
         preserve_line : false,
         screw_ie8     : false,
+        preamble      : null,
     }, true);
 
     var indentation = 0;
@@ -299,6 +300,10 @@ function OutputStream(options) {
         return OUTPUT;
     };
 
+    if (options.preamble) {
+        print(options.preamble.replace(/\r\n?|[\n\u2028\u2029]|\s*$/g, "\n"));
+    }
+
     var stack = [];
     return {
         get             : get,
@@ -378,14 +383,15 @@ function OutputStream(options) {
             var start = self.start;
             if (start && !start._comments_dumped) {
                 start._comments_dumped = true;
-                var comments = start.comments_before;
+                var comments = start.comments_before || [];
 
                 // XXX: ugly fix for https://github.com/mishoo/UglifyJS2/issues/112
                 //      if this node is `return` or `throw`, we cannot allow comments before
                 //      the returned or thrown value.
-                if (self instanceof AST_Exit &&
-                    self.value && self.value.start.comments_before.length > 0) {
-                    comments = (comments || []).concat(self.value.start.comments_before);
+                if (self instanceof AST_Exit && self.value
+                    && self.value.start.comments_before
+                    && self.value.start.comments_before.length > 0) {
+                    comments = comments.concat(self.value.start.comments_before);
                     self.value.start.comments_before = [];
                 }
 
@@ -475,11 +481,7 @@ function OutputStream(options) {
             var so = this.operator, sp = PRECEDENCE[so];
             if (pp > sp
                 || (pp == sp
-                    && this === p.right
-                    && !(so == po &&
-                         (so == "*" ||
-                          so == "&&" ||
-                          so == "||")))) {
+                    && this === p.right)) {
                 return true;
             }
         }
@@ -506,8 +508,17 @@ function OutputStream(options) {
     });
 
     PARENS(AST_Call, function(output){
-        var p = output.parent();
-        return p instanceof AST_New && p.expression === this;
+        var p = output.parent(), p1;
+        if (p instanceof AST_New && p.expression === this)
+            return true;
+
+        // workaround for Safari bug.
+        // https://bugs.webkit.org/show_bug.cgi?id=123506
+        return this.expression instanceof AST_Function
+            && p instanceof AST_PropAccess
+            && p.expression === this
+            && (p1 = output.parent(1)) instanceof AST_Assign
+            && p1.left === p;
     });
 
     PARENS(AST_New, function(output){
@@ -1064,10 +1075,14 @@ function OutputStream(options) {
     });
     DEFPRINT(AST_ObjectSetter, function(self, output){
         output.print("set");
+        output.space();
+        self.key.print(output);
         self.value._do_print(output, true);
     });
     DEFPRINT(AST_ObjectGetter, function(self, output){
         output.print("get");
+        output.space();
+        self.key.print(output);
         self.value._do_print(output, true);
     });
     DEFPRINT(AST_Symbol, function(self, output){

lib/parse.js

@@ -579,10 +579,10 @@ var UNARY_POSTFIX = makePredicate([ "--", "++" ]);
 var ASSIGNMENT = makePredicate([ "=", "+=", "-=", "/=", "*=", "%=", ">>=", "<<=", ">>>=", "|=", "^=", "&=" ]);
 
 var PRECEDENCE = (function(a, ret){
-    for (var i = 0, n = 1; i < a.length; ++i, ++n) {
+    for (var i = 0; i < a.length; ++i) {
         var b = a[i];
         for (var j = 0; j < b.length; ++j) {
-            ret[b[j]] = n;
+            ret[b[j]] = i + 1;
         }
     }
     return ret;
@@ -789,7 +789,7 @@ function parse($TEXT, options) {
                 return for_();
 
               case "function":
-                return function_(true);
+                return function_(AST_Defun);
 
               case "if":
                 return if_();
@@ -933,19 +933,12 @@ function parse($TEXT, options) {
         });
     };
 
-    var function_ = function(in_statement, ctor) {
-        var is_accessor = ctor === AST_Accessor;
-        var name = (is("name") ? as_symbol(in_statement
-                                           ? AST_SymbolDefun
-                                           : is_accessor
-                                           ? AST_SymbolAccessor
-                                           : AST_SymbolLambda)
-                    : is_accessor && (is("string") || is("num")) ? as_atom_node()
-                    : null);
+    var function_ = function(ctor) {
+        var in_statement = ctor === AST_Defun;
+        var name = is("name") ? as_symbol(in_statement ? AST_SymbolDefun : AST_SymbolLambda) : null;
         if (in_statement && !name)
             unexpected();
         expect("(");
-        if (!ctor) ctor = in_statement ? AST_Defun : AST_Function;
         return new ctor({
             name: name,
             argnames: (function(first, a){
@@ -1116,7 +1109,9 @@ function parse($TEXT, options) {
         var tok = S.token, ret;
         switch (tok.type) {
           case "name":
-            return as_symbol(AST_SymbolRef);
+          case "keyword":
+            ret = _make_symbol(AST_SymbolRef);
+            break;
           case "num":
             ret = new AST_Number({ start: tok, end: tok, value: tok.value });
             break;
@@ -1167,7 +1162,7 @@ function parse($TEXT, options) {
         }
         if (is("keyword", "function")) {
             next();
-            var func = function_(false);
+            var func = function_(AST_Function);
             func.start = start;
             func.end = prev();
             return subscripts(func, allow_calls);
@@ -1215,8 +1210,8 @@ function parse($TEXT, options) {
                 if (name == "get") {
                     a.push(new AST_ObjectGetter({
                         start : start,
-                        key   : name,
-                        value : function_(false, AST_Accessor),
+                        key   : as_atom_node(),
+                        value : function_(AST_Accessor),
                         end   : prev()
                     }));
                     continue;
@@ -1224,8 +1219,8 @@ function parse($TEXT, options) {
                 if (name == "set") {
                     a.push(new AST_ObjectSetter({
                         start : start,
-                        key   : name,
-                        value : function_(false, AST_Accessor),
+                        key   : as_atom_node(),
+                        value : function_(AST_Accessor),
                         end   : prev()
                     }));
                     continue;
@@ -1273,17 +1268,21 @@ function parse($TEXT, options) {
         }
     };
 
+    function _make_symbol(type) {
+        var name = S.token.value;
+        return new (name == "this" ? AST_This : type)({
+            name  : String(name),
+            start : S.token,
+            end   : S.token
+        });
+    };
+
     function as_symbol(type, noerror) {
         if (!is("name")) {
             if (!noerror) croak("Name expected");
             return null;
         }
-        var name = S.token.value;
-        var sym = new (name == "this" ? AST_This : type)({
-            name  : String(S.token.value),
-            start : S.token,
-            end   : S.token
-        });
+        var sym = _make_symbol(type);
         next();
         return sym;
     };

lib/scope.js

@@ -64,9 +64,9 @@ SymbolDef.prototype = {
     mangle: function(options) {
         if (!this.mangled_name && !this.unmangleable(options)) {
             var s = this.scope;
-            if (this.orig[0] instanceof AST_SymbolLambda && !options.screw_ie8)
+            if (!options.screw_ie8 && this.orig[0] instanceof AST_SymbolLambda)
                 s = s.parent_scope;
-            this.mangled_name = s.next_mangled(options);
+            this.mangled_name = s.next_mangled(options, this);
         }
     }
 };
@@ -256,6 +256,19 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
     }
 });
 
+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();
+    while (true) {
+        var name = AST_Lambda.prototype.next_mangled.call(this, options, def);
+        if (!(tricky_def && tricky_def.mangled_name == name))
+            return name;
+    }
+});
+
 AST_Scope.DEFMETHOD("references", function(sym){
     if (sym instanceof AST_Symbol) sym = sym.definition();
     return this.enclosed.indexOf(sym) < 0 ? null : sym;

lib/utils.js

@@ -86,12 +86,16 @@ function DefaultsError(msg, defs) {
     this.defs = defs;
 };
 
+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);
+        DefaultsError.croak("`" + 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];
     }

package.json

@@ -3,7 +3,7 @@
     "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
     "homepage": "http://lisperator.net/uglifyjs",
     "main": "tools/node.js",
-    "version": "2.4.1",
+    "version": "2.4.5",
     "engines": { "node" : ">=0.4.0" },
     "maintainers": [{
         "name": "Mihai Bazon",

test/compress/issue-126.js

@@ -10,6 +10,7 @@ concatenate_rhs_strings: {
         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");
@@ -18,5 +19,6 @@ concatenate_rhs_strings: {
         foo(bar() + 123 + "HelloWorldFooBar");
         foo("FooBar" + bar() + "123HelloWorldFooBar");
         foo("Hello" + bar() + "123World");
+        foo(bar() + 'Foo' + (10 + parseInt('10')));
     }
 }

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/sequences.js

@@ -101,10 +101,12 @@ lift_sequences_1: {
 lift_sequences_2: {
     options = { sequences: true, evaluate: true };
     input: {
-        q = 1 + (foo(), bar(), 5) + 7 * (5 / (3 - (a(), (QW=ER), c(), 2))) - (x(), y(), 5);
+        foo.x = (foo = {}, 10);
+        bar = (bar = {}, 10);
     }
     expect: {
-        foo(), bar(), a(), QW = ER, c(), x(), y(), q = 36
+        foo.x = (foo = {}, 10),
+        bar = {}, bar = 10;
     }
 }
 

test/run-tests.js

@@ -7,8 +7,15 @@ var assert = require("assert");
 var sys = require("util");
 
 var tests_dir = path.dirname(module.filename);
+var failures = 0;
+var failed_files = {};
 
 run_compress_tests();
+if (failures) {
+    sys.error("\n!!! Failed " + failures + " test cases.");
+    sys.error("!!! " + Object.keys(failed_files).join(", "));
+    process.exit(1);
+}
 
 /* -----[ utils ]----- */
 
@@ -83,6 +90,8 @@ function run_compress_tests() {
                     output: output,
                     expected: expect
                 });
+                failures++;
+                failed_files[file] = 1;
             }
         }
         var tests = parse_test(path.resolve(dir, file));