v8/test/mjsunit/es8/async-arrow-lexical-new.target.js

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flags: --allow-natives-syntax

function assertEqualsAsync(expected, run, msg) {
  var actual;
  var hadValue = false;
  var hadError = false;
  var promise = run();

  if (typeof promise !== "object" || typeof promise.then !== "function") {
    throw new MjsUnitAssertionError(
        "Expected " + run.toString() +
        " to return a Promise, but it returned " + PrettyPrint(promise));
  }

  promise.then(function(value) { hadValue = true; actual = value; },
               function(error) { hadError = true; actual = error; });

  assertFalse(hadValue || hadError);

  %RunMicrotasks();

  if (hadError) throw actual;

  assertTrue(
      hadValue, "Expected '" + run.toString() + "' to produce a value");

  assertEquals(expected, actual, msg);
};

class BaseClass {
  constructor() {
    return async () => new.target;
  }
}

class ChildClass extends BaseClass {}

assertEqualsAsync(BaseClass, () => new BaseClass()());
assertEqualsAsync(ChildClass, () => new ChildClass()());