/**
 * Copyright 2018 Google Inc. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

async function run() {
  await new Promise(resolve => {
    const w = new Worker("./worker_a.js");
    w.addEventListener("message", ev => {
      if (ev.data === "a") {
        resolve();
      }
    });
  });
  await new Promise(resolve => {
    const w = new Worker("./worker_b.js");
    w.addEventListener("message", ev => {
      if (ev.data === "b") {
        resolve();
      }
    });
  });
  window.parent.postMessage("a", "*");
}

run();