polygerrit-ui/app/behaviors/async-foreach-behavior/async-foreach-behavior.js

/**
 * @license
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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.
 */
(function(window) {
  'use strict';

  window.Gerrit = window.Gerrit || {};

  /** @polymerBehavior Gerrit.AsyncForeachBehavior */
  Gerrit.AsyncForeachBehavior = {
    /**
     * @template T
     * @param {!Array<T>} array
     * @param {!Function} fn An iteratee function to be passed each element of
     *     the array in order. Must return a promise, and the following
     *     iteration will not begin until resolution of the promise returned by
     *     the previous iteration.
     *
     *     An optional second argument to fn is a callback that will halt the
     *     loop if called.
     * @return {!Promise<undefined>}
     */
    asyncForeach(array, fn) {
      if (!array.length) { return Promise.resolve(); }
      let stop = false;
      const stopCallback = () => { stop = true; };
      return fn(array[0], stopCallback).then(exit => {
        if (stop) { return Promise.resolve(); }
        return this.asyncForeach(array.slice(1), fn);
      });
    },
  };

  // eslint-disable-next-line no-unused-vars
  function defineEmptyMixin() {
    // This is a temporary function.
    // Polymer linter doesn't process correctly the following code:
    // class MyElement extends Polymer.mixinBehaviors([legacyBehaviors], ...) {...}
    // To workaround this issue, the mock mixin is declared in this method.
    // In the following changes, legacy behaviors will be converted to mixins.

    /**
     * @polymer
     * @mixinFunction
     */
    Gerrit.AsyncForeachMixin = base =>
      class extends base {
      };
  }
})(window);