ui/file_manager/base/js/mock_chrome.js

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/**
 * Installs a mock object to replace window.chrome in a unit test.
 * @param {Object} mockChrome
 */
function installMockChrome(mockChrome) {
  /** @suppress {const|checkTypes} */
  chrome = mockChrome;
}

/**
 * Mocks chrome.commandLinePrivate.
 */
class MockCommandLinePrivate {
  constructor() {
    this.flags_ = {};
    if (!chrome) {
      installMockChrome({});
    }

    if (!chrome.commandLinePrivate) {
      /** @suppress {checkTypes} */
      chrome.commandLinePrivate = {};
    }
    chrome.commandLinePrivate.hasSwitch = (name, callback) => {
      window.setTimeout(() => {
        callback(name in this.flags_);
      }, 0);
    };
  }

  /**
   * Add a switch.
   * @param {string} name of the switch to add.
   */
  addSwitch(name) {
    this.flags_[name] = true;
  }
}

/**
 * Stubs the chrome.storage API.
 */
class MockChromeStorageAPI {
  constructor() {
    /** @type {Object<?>} */
    this.state = {};

    /** @suppress {const} */
    window.chrome = window.chrome || {};
    /** @suppress {const} */
    window.chrome.runtime = window.chrome.runtime || {};  // For lastError.
    /** @suppress {checkTypes} */
    window.chrome.storage = {
      local: {
        get: this.get_.bind(this),
        set: this.set_.bind(this),
      }
    };
  }

  /**
   * @param {Array<string>|string} keys
   * @param {function(Object<?>)} callback
   * @private
   */
  get_(keys, callback) {
    var keys = keys instanceof Array ? keys : [keys];
    var result = {};
    keys.forEach((key) => {
      if (key in this.state) {
        result[key] = this.state[key];
      }
    });
    callback(result);
  }

  /**
   * @param {Object<?>} values
   * @param {function()=} opt_callback
   * @private
   */
  set_(values, opt_callback) {
    for (var key in values) {
      this.state[key] = values[key];
    }
    if (opt_callback) {
      opt_callback();
    }
  }
}