add benchmark

.npmignore

@@ -3,5 +3,6 @@ node_modules
 *.cache
 lib/6to5/templates
 test
+benchmark
 Makefile
 .*

FEATURES.md

@@ -99,18 +99,16 @@ for (var i of [1, 2, 3]) {
 
 ```javascript
 var obj = {
-  bar: "foobar",
-
   foo() {
     return "foobar";
   },
 
   get bar() {
-
+    return this._bar;
   },
 
-  set bar() {
+  set bar(val) {
-
+    this._bar = val;
   }
 };
 ```
@@ -131,7 +129,7 @@ function printList(name, ...items) {
   items.forEach(function (item) {
     console.log(item);
   });
-};
+}
 ```
 
 ## Spread

Makefile

@@ -3,7 +3,7 @@ MOCHA_CMD = node_modules/mocha/bin/_mocha
 
 export NODE_ENV = test
 
-.PHONY: clean test test-cov test-travis publish
+.PHONY: clean test test-cov test-travis publish bench
 
 clean:
 	rm -rf coverage templates.json
@@ -11,6 +11,9 @@ clean:
 test:
 	$(MOCHA_CMD)
 
+bench:
+	node node_modules/matcha/bin/_matcha
+
 test-cov:
 	make clean
 	node $(ISTANBUL_CMD) $(MOCHA_CMD) --

README.md

@@ -189,25 +189,36 @@ limitations in ES5 implementations.
 
 |                            | 6to5 | Traceur | esnext | es6now | es6-transpiler |
 | -------------------------- | ---- | ------- | ------ | ------ | -------------- |
-| No runtime required        | ✓    |         |        |        | ✓              |
+| No runtime                 | ✓    |         |        |        | ✓              |
-| -------------------------- | ---- | ------- | ------ | ------ | -------------- |
+| Source maps                | ✓    | ✓       | ✓      |        | ✓              |
-| Array comprehension        | ✓    |         | ✓      |        | ✓              |
+| **Compiler usage:**        |      |         |        |        |                |
-| Arrow functions            | ✓    |         | ✓      | ✓      | ✓              |
+| No global pollution        | ✓    |         | ✓      |        | ✓              |
-| Block binding              | ✓    |         |        |        | ✓              |
+| **Syntax features:**       |      |         |        |        |                |
-| Classes                    | ✓    |         | ✓      | ✓      | ✓              |
+| Array comprehension        | ✓    | ✓       | ✓      |        | ✓              |
-| Computed property names    | ✓    |         | ✓      | ✓      | ✓              |
+| Arrow functions            | ✓    | ✓       | ✓      | ✓      | ✓              |
-| Constants                  | ✓    |         |        |        | ✓              |
+| Block binding              | ✓    | ✓       |        |        | ✓              |
-| Default parameters         | ✓    |         | ✓      | ✓      | ✓              |
+| Classes                    | ✓    | ✓       | ✓      | ✓      | ✓              |
-| Destructuring              | ✓    |         | ✓      | ✓      | ✓              |
+| Computed property names    | ✓    | ✓       | ✓      | ✓      | ✓              |
-| For-of                     | ✓    |         | ✓      | ✓      | ✓              |
+| Constants                  | ✓    | ✓       |        |        | ✓              |
-| Generator comprehension    |      |         | ✓      |        | ✓              |
+| Default parameters         | ✓    | ✓       | ✓      | ✓      | ✓              |
-| Generators                 |      |         | ✓      |        |                |
+| Destructuring              | ✓    | ✓       | ✓      | ✓      | ✓              |
-| Modules                    | ✓    |         |        | ✓      |                |
+| For-of                     | ✓    | ✓       | ✓      | ✓      | ✓              |
-| Property method assignment | ✓    |         | ✓      | ✓      | ✓              |
+| Generator comprehension    |      | ✓       | ✓      |        | ✓              |
-| Property name shorthand    | ✓    |         | ✓      | ✓      | ✓              |
+| Generators                 |      | ✓       | ✓      |        |                |
-| Rest parameters            | ✓    |         | ✓      | ✓      | ✓              |
+| Modules                    | ✓    | ✓       |        | ✓      |                |
-| Spread                     | ✓    |         | ✓      | ✓      | ✓              |
+| Property method assignment | ✓    | ✓       | ✓      | ✓      | ✓              |
-| Template literals          | ✓    |         | ✓      | ✓      | ✓              |
+| Property name shorthand    | ✓    | ✓       | ✓      | ✓      | ✓              |
+| Rest parameters            | ✓    | ✓       | ✓      | ✓      | ✓              |
+| Spread                     | ✓    | ✓       | ✓      | ✓      | ✓              |
+| Template literals          | ✓    | ✓       | ✓      | ✓      | ✓              |
+
+#### Performance
+
+    $ make bench
+
+![Output size (including runtime) (lower is better)](http://i.imgur.com/hAybrA2.png)
+
+![Compile speed (higher is better)](http://i.imgur.com/yMwMvhg.png)
 
 ### [Traceur](https://github.com/google/traceur-compiler)
 
@@ -215,10 +226,6 @@ Traceur requires quite a bulky runtime (~75KB) and produces quite verbose code.
 While this can be trimmed down by selectively building the runtime, it's an
 unneccesary step when a runtime can be eliminated entirely.
 
-Instead of mapping to a runtime, 6to5 maps directly to the equivalent ES5. This
-means that your transpiled code will be as simple as possible and is
-**exactly** the equivalent ES5.
-
 ### [esnext](https://github.com/esnext/esnext)
 
 esnext is **slow**, painfully so. Runtime required.
@@ -229,13 +236,9 @@ Doesn't output sourcemaps. This is cited as a positive as line-to-line mapping
 is the goal. This however obviously doesn't retain column mapping resulting in
 the output code not being very pleasant.
 
-Runtime required.
-
 ### [es6-transpiler](https://github.com/termi/es6-transpiler)
 
-Requires shims to compile and pollutes the global scope resulting in possible
+es6-transpiler requires shims to compile and pollutes the global scope resulting
-collisions.
+in possible collisions. es6-transpiler maps line-by-line, just like es6now, this
-
+results in the same issues such as lack of column information and unpleasant
-## Performance
+code output.
-
-    $ make bench

benchmark/fixtures/all.js

@@ -0,0 +1,99 @@
+var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+var obj = {};
+var foo = "foo";
+var bar = "bar";
+
+// constants
+const MULTIPLIER = 5;
+
+// classes
+class Foo {
+  constructor() {
+    this.foo = "bar";
+  }
+}
+
+class Bar extends Foo {
+  constructor() {
+    super();
+  }
+
+  // default parameters
+  go(foo = "bar", bar = "foo") {
+
+  }
+
+  get foo() {
+    return this._foo;
+  }
+
+  set foo(val) {
+    this._foo = val + " foo!";
+  }
+}
+
+// arrow functions
+arr.map(x => x * x);
+
+// block binding
+for (let key in arr) {
+  let val = arr[key];
+  console.log(key, val);
+}
+
+// computed property names
+obj = {
+  ["foo" + bar]: "foobar"
+};
+
+// destructuring
+var [a, [b], c, d] = ["hello", [", ", "junk"], ["world"]];
+console.log(a + b + c);
+
+// array comprehension
+// [for (i of [1, 2, 3]) i * i]; // not supported by es6now
+
+// for-of
+for (var i of [1, 2, 3]) {
+  console.log(i * i);
+}
+
+// property method assignment
+obj = {
+  foo() {
+    return "foobar";
+  },
+
+  get bar() {
+    return this._bar;
+  },
+
+  set bar(val) {
+    this._bar = val;
+  }
+};
+
+// property name shorthand
+function f(x, y) {
+  return { x, y };
+}
+
+// rest parameters
+function printList(name, ...items) {
+  console.log("list %s has the following items", name);
+  items.forEach(function (item) {
+    console.log(item);
+  });
+}
+
+// spread
+function add(x, y) {
+  return x + y;
+}
+var numbers = [5, 10];
+add(...numbers);
+
+// template literals
+var x = 5;
+var y = 10;
+console.log(`${x} + ${y} = ${x + y}`);

benchmark/index.js

@@ -0,0 +1,88 @@
+Error.stackTraceLimit = Infinity;
+
+var traceur = require("traceur");
+var es6tr   = require("es6-transpiler");
+var es6now  = require("es6now");
+var esnext  = require("esnext");
+var to5     = require("../lib/6to5/node");
+
+var matcha  = require("matcha");
+var stream  = require("stream");
+var path    = require("path");
+var fs      = require("fs");
+var vm      = require("vm");
+var _       = require("lodash");
+
+var readResolve = function (filename) {
+  return fs.readFileSync(require.resolve(filename), "utf8");
+};
+
+var compilers = {
+  "6to5": {
+    compile: function (code, filename) {
+      return to5.transform(code, { filename: filename });
+    }
+  },
+
+  traceur: {
+    runtime: readResolve("traceur/bin/traceur-runtime.js"),
+    compile: function (code, filename) {
+      return traceur.compile(code, {
+        modules: "commonjs",
+        experimental: true
+      });
+    }
+  },
+
+  esnext: {
+    runtime: readResolve("esnext/node_modules/regenerator/runtime.js"),
+    compile: function (code, filename) {
+      return esnext.compile(code).code;
+    }
+  },
+
+  es6now: {
+    runtime: readResolve("es6now/runtime/ES6.js"),
+    compile: function (code, filename) {
+      return es6now.translate(code);
+    }
+  },
+
+  "es6-transpiler": {
+    compile: function (code, filename) {
+      var result = es6tr.run({ src: code });
+      if (result.errors.length) throw new Error(result.join("; "));
+      return result.src;
+    }
+  }
+};
+
+_.each(fs.readdirSync(__dirname + "/fixtures"), function (name) {
+  var alias = path.basename(name, path.extname(name));
+
+  suite(alias, function () {
+    set("delay", 0);
+
+    var loc  = __dirname + "/fixtures/" + name;
+    var code = fs.readFileSync(loc, "utf8");
+
+    before(function () {
+      _.each(compilers, function (compiler, name) {
+        var output = compiler.compile(code, loc);
+        if (compiler.runtime) output = compiler.runtime + "\n" + output;
+
+        var kilo  = (output.length / 1024).toFixed(2);
+        console.log(
+          matcha.utils.color(matcha.utils.padBefore(kilo + "KB", 22), "cyan"),
+          matcha.utils.color("» " + name, "gray")
+        );
+      });
+    });
+
+    _.each(compilers, function (compiler, name) {
+      bench(name, function () {
+        compiler.compile(code, loc);
+      });
+    });
+  });
+});

package.json

@@ -17,8 +17,24 @@
     "6to5": "./bin/6to5",
     "6to5-node": "./bin/6to5-node"
   },
+  "keywords": [
+    "es6-transpiler",
+    "scope",
+    "harmony",
+    "blockscope",
+    "block-scope",
+    "let",
+    "const",
+    "var",
+    "es6",
+    "transpile",
+    "transpiler",
+    "traceur",
+    "6to5"
+  ],
   "scripts": {
-    "test": "mocha"
+    "bench": "make bench",
+    "test": "make test"
   },
   "dependencies": {
     "ast-types": "0.5.0",
@@ -32,7 +48,12 @@
     "es6-shim": "^0.18.0"
   },
   "devDependencies": {
+    "es6-transpiler": "0.7.17",
+    "istanbul": "0.3.2",
+    "matcha": "0.5.0",
     "mocha": "1.21.4",
-    "istanbul": "0.3.2"
+    "traceur": "0.0.66",
+    "esnext": "0.11.1",
+    "es6now": "0.8.11"
   }
 }