[es7] Implement async functions parsing

test/mjsunit/harmony/async-keyword.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-sloppy-let
+
+// Make sure we parse async keyword correctly
+// as an identifier (in both sloppy and strict mode)
+
+
+function TestAsyncKeywordSloppyVar() {
+  var async = 10;
+  async = 20;
+  async = function() {};
+  async = function(async) { async: return async; };
+  async = async(30);
+  var t = async + async;
+  assertEquals(async, 30);
+  assertEquals(t, 60);
+}
+TestAsyncKeywordSloppyVar();
+
+
+function TestAsyncKeywordSloppyLet() {
+  let async = 10;
+  async = 20;
+  async = function() {};
+  async = function(async) { async: return async; };
+  async = async(30);
+  var t = async + async;
+  assertEquals(async, 30);
+  assertEquals(t, 60);
+}
+TestAsyncKeywordSloppyLet();
+
+
+function TestAsyncKeywordStrictVar() {
+  'use strict';
+  var async = 10;
+  async = 20;
+  async = function() {};
+  async = function(async) { async: return async; };
+  async = async(30);
+  var t = async + async;
+  assertEquals(async, 30);
+  assertEquals(t, 60);
+}
+TestAsyncKeywordStrictVar();
+
+
+function TestAsyncKeywordStrictLet() {
+  'use strict';
+  let async = 10;
+  async = 20;
+  async = function() {};
+  async = function(async) { async: return async; };
+  async = async(30);
+  var t = async + async;
+  assertEquals(async, 30);
+  assertEquals(t, 60);
+}
+TestAsyncKeywordStrictLet();
+
+
+function TestAsyncKeywordStrictConst() {
+  'use strict';
+  const async = function() { async: return 10; };
+  assertEquals(async(), 10);
+}
+TestAsyncKeywordStrictConst();
+
+
+function TestAsyncClassNameOrObjectSloppy() {
+  class async {
+    async() { return 1; }
+  }
+
+  var c = new async();
+  assertEquals(c.async(), 1);
+
+  var obj = {
+    async: function() {
+      async: var async = 10;
+      return async;
+    }
+  };
+
+  assertEquals(obj.async(), 10);
+
+  var obj2 = {
+    get async() {
+      return 42;
+    }
+  };
+
+  assertEquals(obj2.async, 42);
+}
+TestAsyncClassNameOrObjectSloppy();
+
+
+function TestAsyncClassNameOrObjectStrict() {
+  'use strict';
+  class async {
+    async() { return 1; }
+  }
+
+  var c = new async();
+  assertEquals(c.async(), 1);
+
+  var obj = {
+    async: function() {
+      async: var async = 10;
+      return async;
+    }
+  };
+
+  assertEquals(obj.async(), 10);
+
+  var obj2 = {
+    get async() {
+      return 42;
+    }
+  };
+
+  assertEquals(obj2.async, 42);
+}
+TestAsyncClassNameOrObjectStrict();
+
+
+function TestAsyncGeneratorName() {
+  function* async() { async: yield 1; }
+  assertEquals(async().next().value, 1);
+}
+TestAsyncGeneratorName();
+
+
+function TestAsyncKeywordLineTerminator() {
+  // async identifier followed by a function
+  // keyword on the next line
+  var async = 10;
+  var b = async
+  function foo() {
+    return 15;
+  }
+
+  assertEquals(b, 10);
+  assertEquals(foo(), 15);
+}
+TestAsyncKeywordLineTerminator();