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// 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.
// Test aspects of the generator runtime.
// See:
// http://people.mozilla.org/~jorendorff/es6-draft.html#sec-generatorfunction-objects
function f() { "use strict"; }
function* g() { yield 1; }
var GeneratorFunctionPrototype = Object.getPrototypeOf(g);
var GeneratorFunction = GeneratorFunctionPrototype.constructor;
var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
var IteratorPrototype = Object.getPrototypeOf(GeneratorObjectPrototype);
// 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);
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* () {}));
assertSame("object", typeof GeneratorFunctionPrototype);
var constructor_desc = Object.getOwnPropertyDescriptor(
GeneratorFunctionPrototype, "constructor");
assertTrue(constructor_desc !== undefined);
assertSame(GeneratorFunction, constructor_desc.value);
assertFalse(constructor_desc.writable);
assertFalse(constructor_desc.enumerable);
assertTrue(constructor_desc.configurable);
var prototype_desc = Object.getOwnPropertyDescriptor(
GeneratorFunctionPrototype, "prototype");
assertTrue(prototype_desc !== undefined);
assertSame(GeneratorObjectPrototype, prototype_desc.value);
assertFalse(prototype_desc.writable);
assertFalse(prototype_desc.enumerable);
assertTrue(prototype_desc.configurable);
}
TestGeneratorFunctionPrototype();
// Functions that we associate with generator objects are actually defined by
// a common prototype.
function TestGeneratorObjectPrototype() {
assertSame(IteratorPrototype,
Object.getPrototypeOf(GeneratorObjectPrototype));
assertSame(GeneratorObjectPrototype,
Object.getPrototypeOf((function*(){yield 1}).prototype));
var expected_property_names = ["next", "return", "throw", "constructor"];
var found_property_names =
Object.getOwnPropertyNames(GeneratorObjectPrototype);
expected_property_names.sort();
found_property_names.sort();
assertArrayEquals(expected_property_names, found_property_names);
var constructor_desc = Object.getOwnPropertyDescriptor(
GeneratorObjectPrototype, "constructor");
assertTrue(constructor_desc !== undefined);
assertFalse(constructor_desc.writable);
assertFalse(constructor_desc.enumerable);
assertTrue(constructor_desc.configurable);
var next_desc = Object.getOwnPropertyDescriptor(GeneratorObjectPrototype,
"next");
assertTrue(next_desc !== undefined);
assertTrue(next_desc.writable);
assertFalse(next_desc.enumerable);
assertTrue(next_desc.configurable);
var throw_desc = Object.getOwnPropertyDescriptor(GeneratorObjectPrototype,
"throw");
assertTrue(throw_desc !== undefined);
assertTrue(throw_desc.writable);
assertFalse(throw_desc.enumerable);
assertTrue(throw_desc.configurable);
}
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);
// ES6 draft 04-14-15, section 25.2.2.2
var prototype_desc = Object.getOwnPropertyDescriptor(GeneratorFunction,
"prototype");
assertFalse(prototype_desc.writable);
assertFalse(prototype_desc.enumerable);
assertFalse(prototype_desc.configurable);
}
TestGeneratorFunction();
function TestPerGeneratorPrototype() {
assertTrue((function*(){}).prototype !== (function*(){}).prototype);
assertTrue((function*(){}).prototype !== g.prototype);
assertSame(GeneratorObjectPrototype, Object.getPrototypeOf(g.prototype));
assertTrue(!(g.prototype instanceof Function));
assertSame(typeof (g.prototype), "object");
assertArrayEquals([], Object.getOwnPropertyNames(g.prototype));
}
TestPerGeneratorPrototype();