Stage ES6 generators

test/mjsunit/harmony/generators-runtime.js

-// Copyright 2013 the V8 project authors. All rights reserved.
-// 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.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "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
-// OWNER OR CONTRIBUTORS 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.
-
-// Flags: --harmony-generators
-
-// Test aspects of the generator runtime.
-
-// See:
-// http://people.mozilla.org/~jorendorff/es6-draft.html#sec-generatorfunction-objects
-
-function f() { }
-function* g() { yield 1; }
-var GeneratorFunctionPrototype = Object.getPrototypeOf(g);
-var GeneratorFunction = GeneratorFunctionPrototype.constructor;
-var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
-
-// A generator function should have the same set of properties as any
-// other function.
-function TestGeneratorFunctionInstance() {
-  var f_own_property_names = Object.getOwnPropertyNames(f);
-  var g_own_property_names = Object.getOwnPropertyNames(g);
-
-  f_own_property_names.sort();
-  g_own_property_names.sort();
-
-  assertArrayEquals(f_own_property_names, g_own_property_names);
-  var i;
-  for (i = 0; i < f_own_property_names.length; i++) {
-    var prop = f_own_property_names[i];
-    var f_desc = Object.getOwnPropertyDescriptor(f, prop);
-    var g_desc = Object.getOwnPropertyDescriptor(g, prop);
-    assertEquals(f_desc.configurable, g_desc.configurable, prop);
-    if (prop === 'arguments' || prop === 'caller') {
-      // Unlike sloppy functions, which have read-only data arguments and caller
-      // properties, sloppy generators have a poison pill implemented via
-      // accessors
-      assertFalse('writable' in g_desc, prop);
-      assertTrue(g_desc.get instanceof Function, prop);
-      assertEquals(g_desc.get, g_desc.set, prop);
-    } else {
-      assertEquals(f_desc.writable, g_desc.writable, prop);
-    }
-    assertEquals(f_desc.enumerable, g_desc.enumerable, prop);
-  }
-}
-TestGeneratorFunctionInstance();
-
-
-// Generators have an additional object interposed in the chain between
-// themselves and Function.prototype.
-function TestGeneratorFunctionPrototype() {
-  // Sanity check.
-  assertSame(Object.getPrototypeOf(f), Function.prototype);
-  assertFalse(GeneratorFunctionPrototype === Function.prototype);
-  assertSame(Function.prototype,
-             Object.getPrototypeOf(GeneratorFunctionPrototype));
-  assertSame(GeneratorFunctionPrototype,
-             Object.getPrototypeOf(function* () {}));
-}
-TestGeneratorFunctionPrototype();
-
-
-// Functions that we associate with generator objects are actually defined by
-// a common prototype.
-function TestGeneratorObjectPrototype() {
-  assertSame(Object.prototype,
-             Object.getPrototypeOf(GeneratorObjectPrototype));
-  assertSame(GeneratorObjectPrototype,
-             Object.getPrototypeOf((function*(){yield 1}).prototype));
-
-  var expected_property_names = ["next", "throw", "constructor"];
-  var found_property_names =
-      Object.getOwnPropertyNames(GeneratorObjectPrototype);
-
-  expected_property_names.sort();
-  found_property_names.sort();
-
-  assertArrayEquals(expected_property_names, found_property_names);
-
-  iterator_desc = Object.getOwnPropertyDescriptor(GeneratorObjectPrototype,
-      Symbol.iterator);
-  assertTrue(iterator_desc !== undefined);
-  assertFalse(iterator_desc.writable);
-  assertFalse(iterator_desc.enumerable);
-  assertFalse(iterator_desc.configurable);
-
-  // The generator object's "iterator" function is just the identity.
-  assertSame(iterator_desc.value.call(42), 42);
-}
-TestGeneratorObjectPrototype();
-
-
-// This tests the object that would be called "GeneratorFunction", if it were
-// like "Function".
-function TestGeneratorFunction() {
-  assertSame(GeneratorFunctionPrototype, GeneratorFunction.prototype);
-  assertTrue(g instanceof GeneratorFunction);
-
-  assertSame(Function, Object.getPrototypeOf(GeneratorFunction));
-  assertTrue(g instanceof Function);
-
-  assertEquals("function* g() { yield 1; }", g.toString());
-
-  // Not all functions are generators.
-  assertTrue(f instanceof Function);  // Sanity check.
-  assertTrue(!(f instanceof GeneratorFunction));
-
-  assertTrue((new GeneratorFunction()) instanceof GeneratorFunction);
-  assertTrue(GeneratorFunction() instanceof GeneratorFunction);
-}
-TestGeneratorFunction();
-
-
-function TestPerGeneratorPrototype() {
-  assertTrue((function*(){}).prototype !== (function*(){}).prototype);
-  assertTrue((function*(){}).prototype !== g.prototype);
-  assertTrue(g.prototype instanceof GeneratorFunctionPrototype);
-  assertSame(GeneratorObjectPrototype, Object.getPrototypeOf(g.prototype));
-  assertTrue(!(g.prototype instanceof Function));
-  assertSame(typeof (g.prototype), "object");
-
-  assertArrayEquals([], Object.getOwnPropertyNames(g.prototype));
-}
-TestPerGeneratorPrototype();