js/src/tests/ecma_2017/AsyncFunctions/subclass.js


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// |reftest| skip-if(!xulRuntime.shell) -- needs drainJobQueue
/* 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 AsyncFunction = async function(){}.constructor;

class MyAsync extends AsyncFunction {}

// MyGen inherits from %AsyncFunction%.
assertEq(Object.getPrototypeOf(MyAsync), AsyncFunction);

// MyGen.prototype inherits from %AsyncFunctionPrototype%.
assertEq(Object.getPrototypeOf(MyAsync.prototype), AsyncFunction.prototype);

var fn = new MyAsync("return await 'ok';");

// fn inherits from MyAsync.prototype.
assertEq(Object.getPrototypeOf(fn), MyAsync.prototype);

// Ensure the new async function can be executed.
var promise = fn();

// promise inherits from %Promise.prototype%.
assertEq(Object.getPrototypeOf(promise), Promise.prototype);

// Computes the expected result.
assertEventuallyEq(promise, "ok");

if (typeof reportCompare === "function")
    reportCompare(0, 0);