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//
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8//     * Redistributions in binary form must reproduce the above
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15//
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17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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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
36function f() { }
37function* g() { yield 1; }
38var GeneratorFunctionPrototype = Object.getPrototypeOf(g);
39var GeneratorFunction = GeneratorFunctionPrototype.constructor;
40var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
41
42// A generator function should have the same set of properties as any
43// other function.
44function 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}
62TestGeneratorFunctionInstance();
63
64
65// Generators have an additional object interposed in the chain between
66// themselves and Function.prototype.
67function 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}
76TestGeneratorFunctionPrototype();
77
78
79// Functions that we associate with generator objects are actually defined by
80// a common prototype.
81function 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}
96TestGeneratorObjectPrototype();
97
98
99// This tests the object that would be called "GeneratorFunction", if it were
100// like "Function".
101function 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}
117TestGeneratorFunction();
118
119
120function 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}
130TestPerGeneratorPrototype();
131