subclass.js - mozsearch

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/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

const GeneratorFunction = function*(){}.constructor;

class MyGen extends GeneratorFunction {}

// MyGen inherits from %GeneratorFunction%.

assertEq(Object.getPrototypeOf(MyGen), GeneratorFunction);

// MyGen.prototype inherits from %Generator%.

assertEq(Object.getPrototypeOf(MyGen.prototype), GeneratorFunction.prototype);

var fn = new MyGen("yield* [1, 2, 3]");

// fn inherits from MyGen.prototype.

assertEq(Object.getPrototypeOf(fn), MyGen.prototype);

// fn.prototype inherits from %GeneratorPrototype%.

assertEq(Object.getPrototypeOf(fn.prototype), GeneratorFunction.prototype.prototype);

// Ensure the new generator function can be executed.

var it = fn();

// it inherits from fn.prototype.

assertEq(Object.getPrototypeOf(it), fn.prototype);

// Computes the expected result.

assertEqArray([...it], [1, 2, 3]);

if (typeof reportCompare === "function")

    reportCompare(0, 0);