40 lines
1.1 KiB
JavaScript
40 lines
1.1 KiB
JavaScript
// Iterator prototype surfaces.
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load(libdir + "asserts.js");
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load(libdir + "iteration.js");
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var iterProto = null;
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function test(constructor) {
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var iter = new constructor()[Symbol.iterator]();
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assertDeepEq(Reflect.ownKeys(iter), []);
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// Iterator prototypes only have a .next and @@toStringTag property.
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var proto1 = Object.getPrototypeOf(iter);
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assertDeepEq(Reflect.ownKeys(proto1), ['next', Symbol.toStringTag]);
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var desc = Object.getOwnPropertyDescriptor(proto1, 'next');
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assertEq(desc.configurable, true);
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assertEq(desc.enumerable, false);
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assertEq(desc.writable, true);
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// %IteratorPrototype%
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var proto2 = Object.getPrototypeOf(proto1);
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assertEq(Object.getPrototypeOf(proto2), Object.prototype);
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assertEq(Object.prototype.toString.call(proto2), "[object Object]");
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assertDeepEq(Reflect.ownKeys(proto2), [Symbol.iterator]);
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assertEq(proto2[Symbol.iterator](), proto2);
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// Check there's a single %IteratorPrototype% object.
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if (iterProto === null)
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iterProto = proto2;
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else
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assertEq(iterProto, proto2);
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}
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test(Array);
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test(String);
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test(Map);
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test(Set);
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