1 // Copyright 2013 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 // Flags: --harmony-generators 29 30 // Test aspects of the generator runtime. 31 32 // FIXME(wingo): Replace this reference with a more official link. 33 // See: 34 // http://wiki.ecmascript.org/lib/exe/fetch.php?cache=cache&media=harmony:es6_generator_object_model_3-29-13.png 35 36 function f() { } 37 function* g() { yield 1; } 38 var GeneratorFunctionPrototype = Object.getPrototypeOf(g); 39 var GeneratorFunction = GeneratorFunctionPrototype.constructor; 40 var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype; 41 42 // A generator function should have the same set of properties as any 43 // other function. 44 function TestGeneratorFunctionInstance() { 45 var f_own_property_names = Object.getOwnPropertyNames(f); 46 var g_own_property_names = Object.getOwnPropertyNames(g); 47 48 f_own_property_names.sort(); 49 g_own_property_names.sort(); 50 51 assertArrayEquals(f_own_property_names, g_own_property_names); 52 var i; 53 for (i = 0; i < f_own_property_names.length; i++) { 54 var prop = f_own_property_names[i]; 55 var f_desc = Object.getOwnPropertyDescriptor(f, prop); 56 var g_desc = Object.getOwnPropertyDescriptor(g, prop); 57 assertEquals(f_desc.configurable, g_desc.configurable, prop); 58 assertEquals(f_desc.writable, g_desc.writable, prop); 59 assertEquals(f_desc.enumerable, g_desc.enumerable, prop); 60 } 61 } 62 TestGeneratorFunctionInstance(); 63 64 65 // Generators have an additional object interposed in the chain between 66 // themselves and Function.prototype. 67 function TestGeneratorFunctionPrototype() { 68 // Sanity check. 69 assertSame(Object.getPrototypeOf(f), Function.prototype); 70 assertFalse(GeneratorFunctionPrototype === Function.prototype); 71 assertSame(Function.prototype, 72 Object.getPrototypeOf(GeneratorFunctionPrototype)); 73 assertSame(GeneratorFunctionPrototype, 74 Object.getPrototypeOf(function* () {})); 75 } 76 TestGeneratorFunctionPrototype(); 77 78 79 // Functions that we associate with generator objects are actually defined by 80 // a common prototype. 81 function TestGeneratorObjectPrototype() { 82 assertSame(Object.prototype, 83 Object.getPrototypeOf(GeneratorObjectPrototype)); 84 assertSame(GeneratorObjectPrototype, 85 Object.getPrototypeOf((function*(){yield 1}).prototype)); 86 87 var expected_property_names = ["next", "throw", "constructor"]; 88 var found_property_names = 89 Object.getOwnPropertyNames(GeneratorObjectPrototype); 90 91 expected_property_names.sort(); 92 found_property_names.sort(); 93 94 assertArrayEquals(expected_property_names, found_property_names); 95 } 96 TestGeneratorObjectPrototype(); 97 98 99 // This tests the object that would be called "GeneratorFunction", if it were 100 // like "Function". 101 function TestGeneratorFunction() { 102 assertSame(GeneratorFunctionPrototype, GeneratorFunction.prototype); 103 assertTrue(g instanceof GeneratorFunction); 104 105 assertSame(Function, Object.getPrototypeOf(GeneratorFunction)); 106 assertTrue(g instanceof Function); 107 108 assertEquals("function* g() { yield 1; }", g.toString()); 109 110 // Not all functions are generators. 111 assertTrue(f instanceof Function); // Sanity check. 112 assertTrue(!(f instanceof GeneratorFunction)); 113 114 assertTrue((new GeneratorFunction()) instanceof GeneratorFunction); 115 assertTrue(GeneratorFunction() instanceof GeneratorFunction); 116 } 117 TestGeneratorFunction(); 118 119 120 function TestPerGeneratorPrototype() { 121 assertTrue((function*(){}).prototype !== (function*(){}).prototype); 122 assertTrue((function*(){}).prototype !== g.prototype); 123 assertTrue(g.prototype instanceof GeneratorFunctionPrototype); 124 assertSame(GeneratorObjectPrototype, Object.getPrototypeOf(g.prototype)); 125 assertTrue(!(g.prototype instanceof Function)); 126 assertSame(typeof (g.prototype), "object"); 127 128 assertArrayEquals([], Object.getOwnPropertyNames(g.prototype)); 129 } 130 TestPerGeneratorPrototype(); 131
