google-closure-library/closure/goog/testing/events/events.js

Google's common JavaScript library

/**
 * @license
 * Copyright The Closure Library Authors.
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @fileoverview Event Simulation.
 *
 * Utility functions for simulating events at the Closure level. All functions
 * in this package generate events by calling goog.events.fireListeners,
 * rather than interfacing with the browser directly. This is intended for
 * testing purposes, and should not be used in production code.
 *
 * The decision to use Closure events and dispatchers instead of the browser's
 * native events and dispatchers was conscious and deliberate. Native event
 * dispatchers have their own set of quirks and edge cases. Pure JS dispatchers
 * are more robust and transparent.
 *
 * If you think you need a testing mechanism that uses native Event objects,
 * please, please email closure-tech first to explain your use case before you
 * sink time into this.
 *
 * TODO(user): Migrate to explicitly non-nullable types. At present, many
 *     functions in this file expect non-null inputs but do not explicitly
 *     indicate this.
 */

goog.setTestOnly('goog.testing.events');
goog.provide('goog.testing.events');
goog.provide('goog.testing.events.Event');

goog.require('goog.Disposable');
goog.require('goog.asserts');
goog.require('goog.dom.NodeType');
goog.require('goog.events');
goog.require('goog.events.BrowserEvent');
goog.require('goog.events.EventTarget');
goog.require('goog.events.EventType');
goog.require('goog.events.KeyCodes');
goog.require('goog.object');
goog.require('goog.style');
goog.require('goog.userAgent');
goog.requireType('goog.math.Coordinate');



/**
 * goog.events.BrowserEvent expects an Event so we provide one for JSCompiler.
 *
 * This clones a lot of the functionality of goog.events.Event. This used to
 * use a mixin, but the mixin results in confusing the two types when compiled.
 *
 * @param {string} type Event Type.
 * @param {Object=} opt_target Reference to the object that is the target of
 *     this event.
 * @constructor
 * @extends {Event}
 */
goog.testing.events.Event = function(type, opt_target) {
  'use strict';
  this.type = type;

  this.target = /** @type {EventTarget} */ (opt_target || null);

  this.currentTarget = this.target;
};


/**
 * Whether to cancel the event in internal capture/bubble processing for IE.
 * @type {boolean}
 * @public
 * @suppress {underscore|visibility} Technically public, but referencing this
 *     outside this package is strongly discouraged.
 */
goog.testing.events.Event.prototype.propagationStopped_ = false;


/** @override */
goog.testing.events.Event.prototype.defaultPrevented = false;


/**
 * Return value for in internal capture/bubble processing for IE.
 * @type {boolean}
 * @public
 * @suppress {underscore|visibility} Technically public, but referencing this
 *     outside this package is strongly discouraged.
 */
goog.testing.events.Event.prototype.returnValue_ = true;


/** @override */
goog.testing.events.Event.prototype.stopPropagation = function() {
  'use strict';
  this.propagationStopped_ = true;
};


/** @override */
goog.testing.events.Event.prototype.preventDefault = function() {
  'use strict';
  this.defaultPrevented = true;
  this.returnValue_ = false;
};

/**
 * Asserts an event target exists.  This will fail if target is not defined.
 *
 * TODO(nnaze): Gradually add this to the methods in this file, and eventually
 *     update the method signatures to not take nullables.  See
 * http://b/8961907
 *
 * @param {EventTarget} target A target to assert.
 * @return {!EventTarget} The target, guaranteed to exist.
 * @private
 */
goog.testing.events.assertEventTarget_ = function(target) {
  'use strict';
  return goog.asserts.assert(target, 'EventTarget should be defined.');
};


/**
 * A static helper function that sets the mouse position to the event.
 * @param {Event} event A simulated native event.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @private
 */
goog.testing.events.setEventClientXY_ = function(event, opt_coords) {
  'use strict';
  if (!opt_coords && event.target &&
      /** @type {!Node} */ (event.target).nodeType ==
          goog.dom.NodeType.ELEMENT) {
    try {
      opt_coords = goog.style.getClientPosition(
          /** @type {!Element} **/ (event.target));
    } catch (ex) {
      // IE sometimes throws if it can't get the position.
    }
  }
  event.clientX = opt_coords ? opt_coords.x : 0;
  event.clientY = opt_coords ? opt_coords.y : 0;

  // Pretend the browser window is at (0, 0) of the screen.
  event.screenX = event.clientX;
  event.screenY = event.clientY;

  // Assume that there was no page scroll.
  event.pageX = event.clientX;
  event.pageY = event.clientY;
};


/**
 * Simulates a mousedown, mouseup, and then click on the given event target,
 * with the left mouse button.
 * @param {EventTarget} target The target for the event.
 * @param {goog.events.BrowserEvent.MouseButton=} opt_button Mouse button;
 *     defaults to `goog.events.BrowserEvent.MouseButton.LEFT`.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the sequence: false if preventDefault()
 *     was called on any of the events, true otherwise.
 */
goog.testing.events.fireClickSequence = function(
    target, opt_button, opt_coords, opt_eventProperties) {
  'use strict';
  // Fire mousedown, mouseup, and click. Then return the bitwise AND of the 3.
  return goog.testing.events.eagerAnd_(
      goog.testing.events.fireMouseDownEvent(
          target, opt_button, opt_coords, opt_eventProperties),
      goog.testing.events.fireMouseUpEvent(
          target, opt_button, opt_coords, opt_eventProperties),
      goog.testing.events.fireClickEvent(
          target, opt_button, opt_coords, opt_eventProperties));
};


/**
 * Simulates the sequence of events fired by the browser when the user double-
 * clicks the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the sequence: false if preventDefault()
 *     was called on any of the events, true otherwise.
 */
goog.testing.events.fireDoubleClickSequence = function(
    target, opt_coords, opt_eventProperties) {
  'use strict';
  // Fire mousedown, mouseup, click, mousedown, mouseup, click, dblclick.
  // Then return the bitwise AND of the 7.
  const btn = goog.events.BrowserEvent.MouseButton.LEFT;
  return goog.testing.events.eagerAnd_(
      goog.testing.events.fireMouseDownEvent(
          target, btn, opt_coords, opt_eventProperties),
      goog.testing.events.fireMouseUpEvent(
          target, btn, opt_coords, opt_eventProperties),
      goog.testing.events.fireClickEvent(
          target, btn, opt_coords, opt_eventProperties),
      // IE fires a selectstart instead of the second mousedown in a
      // dblclick, but we don't care about selectstart.
      (goog.userAgent.IE ||
       goog.testing.events.fireMouseDownEvent(
           target, btn, opt_coords, opt_eventProperties)),
      goog.testing.events.fireMouseUpEvent(
          target, btn, opt_coords, opt_eventProperties),
      // IE doesn't fire the second click in a dblclick.
      (goog.userAgent.IE ||
       goog.testing.events.fireClickEvent(
           target, btn, opt_coords, opt_eventProperties)),
      goog.testing.events.fireDoubleClickEvent(
          target, opt_coords, opt_eventProperties));
};


/**
 * A non-exhaustive mapping of keys to keyCode. These are not localized and
 * are specific to QWERTY keyboards, but are used to augment our testing key
 * events as much as possible in order to simulate real browser events. This
 * will be used to fill out the `keyCode` field for key events when the `key`
 * value is present in this map.
 * @private {!Object<number>}
 * @final
 */
goog.testing.events.KEY_TO_KEYCODE_MAPPING_ = {
  '0': goog.events.KeyCodes.ZERO,
  '1': goog.events.KeyCodes.ONE,
  '2': goog.events.KeyCodes.TWO,
  '3': goog.events.KeyCodes.THREE,
  '4': goog.events.KeyCodes.FOUR,
  '5': goog.events.KeyCodes.FIVE,
  '6': goog.events.KeyCodes.SIX,
  '7': goog.events.KeyCodes.SEVEN,
  '8': goog.events.KeyCodes.EIGHT,
  '9': goog.events.KeyCodes.NINE,
  'a': goog.events.KeyCodes.A,
  'b': goog.events.KeyCodes.B,
  'c': goog.events.KeyCodes.C,
  'd': goog.events.KeyCodes.D,
  'e': goog.events.KeyCodes.E,
  'f': goog.events.KeyCodes.F,
  'g': goog.events.KeyCodes.G,
  'h': goog.events.KeyCodes.H,
  'i': goog.events.KeyCodes.I,
  'j': goog.events.KeyCodes.J,
  'k': goog.events.KeyCodes.K,
  'l': goog.events.KeyCodes.L,
  'm': goog.events.KeyCodes.M,
  'n': goog.events.KeyCodes.N,
  'o': goog.events.KeyCodes.O,
  'p': goog.events.KeyCodes.P,
  'q': goog.events.KeyCodes.Q,
  'r': goog.events.KeyCodes.R,
  's': goog.events.KeyCodes.S,
  't': goog.events.KeyCodes.T,
  'u': goog.events.KeyCodes.U,
  'v': goog.events.KeyCodes.V,
  'w': goog.events.KeyCodes.W,
  'x': goog.events.KeyCodes.X,
  'y': goog.events.KeyCodes.Y,
  'z': goog.events.KeyCodes.Z
};


/**
 * Simulates a complete keystroke (keydown, keypress, and keyup). Note that
 * if preventDefault is called on the keydown, the keypress will not fire.
 *
 * @param {EventTarget} target The target for the event.
 * @param {string|number} keyOrKeyCode The key value or keycode of the key
 *     pressed.
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the sequence: false if preventDefault()
 *     was called on any of the events, true otherwise.
 */
goog.testing.events.fireKeySequence = function(
    target, keyOrKeyCode, opt_eventProperties) {
  'use strict';
  return goog.testing.events.fireNonAsciiKeySequence(
      target, keyOrKeyCode, keyOrKeyCode, opt_eventProperties);
};


/**
 * Simulates a complete keystroke (keydown, keypress, and keyup) when typing
 * a non-ASCII character. Same as fireKeySequence, the keypress will not fire
 * if preventDefault is called on the keydown.
 *
 * @param {EventTarget} target The target for the event.
 * @param {string|number} keyOrKeyCode The key value or keycode of the keydown
 *     and keyup events.
 * @param {string|number} keyPressKeyOrKeyCode The key value or keycode of the
 *     keypress event.
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the sequence: false if preventDefault()
 *     was called on any of the events, true otherwise.
 */
goog.testing.events.fireNonAsciiKeySequence = function(
    target, keyOrKeyCode, keyPressKeyOrKeyCode, opt_eventProperties) {
  'use strict';
  const keydown =
      /** @type {!KeyboardEvent} */ (
          /** @type {!Event} */ (new goog.testing.events.Event(
              goog.events.EventType.KEYDOWN, target)));
  const keyup =  //
      /** @type {!KeyboardEvent} */ (
          /** @type {!Event} */ (new goog.testing.events.Event(
              goog.events.EventType.KEYUP, target)));
  const keypress =
      /** @type {!KeyboardEvent} */ (
          /** @type {!Event} */ (new goog.testing.events.Event(
              goog.events.EventType.KEYPRESS, target)));

  if (typeof keyOrKeyCode === 'string') {
    keydown.key = keyup.key = /** @type {string} */ (keyOrKeyCode);
    keypress.key = /** @type {string} */ (keyPressKeyOrKeyCode);

    // Try to fill the keyCode field for the key events if we have a known key.
    // This is to try and make these mock simulated event as close to real
    // browser events as possible.
    const mappedKeyCode =
        goog.testing.events
            .KEY_TO_KEYCODE_MAPPING_[/** @type {string} */ (keyOrKeyCode)
                                         .toLowerCase()];
    if (mappedKeyCode) {
      keydown.keyCode = keyup.keyCode = mappedKeyCode;
    }

    const mappedKeyPressKeyCode =
        goog.testing.events.KEY_TO_KEYCODE_MAPPING_[/** @type {string} */ (
                                                        keyPressKeyOrKeyCode)
                                                        .toLowerCase()];
    if (mappedKeyPressKeyCode) {
      keypress.keyCode = mappedKeyPressKeyCode;
    }
  } else {
    keydown.keyCode = keyup.keyCode = /** @type {number} */ (keyOrKeyCode);
    keypress.keyCode = /** @type {number} */ (keyPressKeyOrKeyCode);
  }

  if (opt_eventProperties) {
    goog.object.extend(keydown, opt_eventProperties);
    goog.object.extend(keyup, opt_eventProperties);
    goog.object.extend(keypress, opt_eventProperties);
  }

  // Fire keydown, keypress, and keyup. Note that if the keydown is
  // prevent-defaulted, then the keypress will not fire.
  let result = goog.testing.events.fireBrowserEvent(keydown);
  if (typeof keyOrKeyCode === 'string') {
    if (/** @type {string} */ (keyPressKeyOrKeyCode) != '' && result) {
      result = goog.testing.events.eagerAnd_(
          result, goog.testing.events.fireBrowserEvent(keypress));
    }
  } else {
    if (goog.events.KeyCodes.firesKeyPressEvent(
            /** @type {number} */ (keyOrKeyCode), undefined, keydown.shiftKey,
            keydown.ctrlKey, keydown.altKey, keydown.metaKey) &&
        result) {
      result = goog.testing.events.eagerAnd_(
          result, goog.testing.events.fireBrowserEvent(keypress));
    }
  }
  return goog.testing.events.eagerAnd_(
      result, goog.testing.events.fireBrowserEvent(keyup));
};


/**
 * Simulates a mouseenter event on the given target.
 * @param {!EventTarget} target The target for the event.
 * @param {?EventTarget} relatedTarget The related target for the event (e.g.,
 *     the node that the mouse is being moved out of).
 * @param {!goog.math.Coordinate=} opt_coords Mouse position. Defaults to
 *     event's target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseEnterEvent = function(
    target, relatedTarget, opt_coords) {
  'use strict';
  const mouseenter =
      new goog.testing.events.Event(goog.events.EventType.MOUSEENTER, target);
  mouseenter.relatedTarget = relatedTarget;
  goog.testing.events.setEventClientXY_(mouseenter, opt_coords);
  return goog.testing.events.fireBrowserEvent(mouseenter);
};


/**
 * Simulates a mouseleave event on the given target.
 * @param {!EventTarget} target The target for the event.
 * @param {?EventTarget} relatedTarget The related target for the event (e.g.,
 *     the node that the mouse is being moved into).
 * @param {!goog.math.Coordinate=} opt_coords Mouse position. Defaults to
 *     event's target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseLeaveEvent = function(
    target, relatedTarget, opt_coords) {
  'use strict';
  const mouseleave =
      new goog.testing.events.Event(goog.events.EventType.MOUSELEAVE, target);
  mouseleave.relatedTarget = relatedTarget;
  goog.testing.events.setEventClientXY_(mouseleave, opt_coords);
  return goog.testing.events.fireBrowserEvent(mouseleave);
};


/**
 * Simulates a mouseover event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {EventTarget} relatedTarget The related target for the event (e.g.,
 *     the node that the mouse is being moved out of).
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseOverEvent = function(
    target, relatedTarget, opt_coords) {
  'use strict';
  const mouseover =
      new goog.testing.events.Event(goog.events.EventType.MOUSEOVER, target);
  mouseover.relatedTarget = relatedTarget;
  goog.testing.events.setEventClientXY_(mouseover, opt_coords);
  return goog.testing.events.fireBrowserEvent(mouseover);
};


/**
 * Simulates a mousemove event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseMoveEvent = function(target, opt_coords) {
  'use strict';
  const mousemove =
      new goog.testing.events.Event(goog.events.EventType.MOUSEMOVE, target);

  goog.testing.events.setEventClientXY_(mousemove, opt_coords);
  return goog.testing.events.fireBrowserEvent(mousemove);
};


/**
 * Simulates a mouseout event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {EventTarget} relatedTarget The related target for the event (e.g.,
 *     the node that the mouse is being moved into).
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseOutEvent = function(
    target, relatedTarget, opt_coords) {
  'use strict';
  const mouseout =
      new goog.testing.events.Event(goog.events.EventType.MOUSEOUT, target);
  mouseout.relatedTarget = relatedTarget;
  goog.testing.events.setEventClientXY_(mouseout, opt_coords);
  return goog.testing.events.fireBrowserEvent(mouseout);
};


/**
 * Simulates a mousedown event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.events.BrowserEvent.MouseButton=} opt_button Mouse button;
 *     defaults to `goog.events.BrowserEvent.MouseButton.LEFT`.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseDownEvent = function(
    target, opt_button, opt_coords, opt_eventProperties) {
  'use strict';
  let button = opt_button || goog.events.BrowserEvent.MouseButton.LEFT;
  return goog.testing.events.fireMouseButtonEvent_(
      goog.events.EventType.MOUSEDOWN, target, button, opt_coords,
      opt_eventProperties);
};


/**
 * Simulates a mouseup event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.events.BrowserEvent.MouseButton=} opt_button Mouse button;
 *     defaults to `goog.events.BrowserEvent.MouseButton.LEFT`.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireMouseUpEvent = function(
    target, opt_button, opt_coords, opt_eventProperties) {
  'use strict';
  let button = opt_button || goog.events.BrowserEvent.MouseButton.LEFT;
  return goog.testing.events.fireMouseButtonEvent_(
      goog.events.EventType.MOUSEUP, target, button, opt_coords,
      opt_eventProperties);
};


/**
 * Simulates a click event on the given target. IE only supports click with
 * the left mouse button.
 * @param {EventTarget} target The target for the event.
 * @param {goog.events.BrowserEvent.MouseButton=} opt_button Mouse button;
 *     defaults to `goog.events.BrowserEvent.MouseButton.LEFT`.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireClickEvent = function(
    target, opt_button, opt_coords, opt_eventProperties) {
  'use strict';
  return goog.testing.events.fireMouseButtonEvent_(
      goog.events.EventType.CLICK, target, opt_button, opt_coords,
      opt_eventProperties);
};


/**
 * Simulates a double-click event on the given target. Always double-clicks
 * with the left mouse button since no browser supports double-clicking with
 * any other buttons.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireDoubleClickEvent = function(
    target, opt_coords, opt_eventProperties) {
  'use strict';
  return goog.testing.events.fireMouseButtonEvent_(
      goog.events.EventType.DBLCLICK, target,
      goog.events.BrowserEvent.MouseButton.LEFT, opt_coords,
      opt_eventProperties);
};


/**
 * Helper function to fire a mouse event.
 * with the left mouse button since no browser supports double-clicking with
 * any other buttons.
 * @param {string} type The event type.
 * @param {EventTarget} target The target for the event.
 * @param {number=} opt_button Mouse button; defaults to
 *     `goog.events.BrowserEvent.MouseButton.LEFT`.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 * @private
 */
goog.testing.events.fireMouseButtonEvent_ = function(
    type, target, opt_button, opt_coords, opt_eventProperties) {
  'use strict';
  const e = new goog.testing.events.Event(type, target);
  e.button = opt_button || goog.events.BrowserEvent.MouseButton.LEFT;
  goog.testing.events.setEventClientXY_(e, opt_coords);
  if (opt_eventProperties) {
    goog.object.extend(e, opt_eventProperties);
  }
  return goog.testing.events.fireBrowserEvent(e);
};


/**
 * Simulates a contextmenu event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireContextMenuEvent = function(target, opt_coords) {
  'use strict';
  const button = (goog.userAgent.MAC && goog.userAgent.WEBKIT) ?
      goog.events.BrowserEvent.MouseButton.LEFT :
      goog.events.BrowserEvent.MouseButton.RIGHT;
  const contextmenu =
      new goog.testing.events.Event(goog.events.EventType.CONTEXTMENU, target);
  contextmenu.button = button;
  contextmenu.ctrlKey = goog.userAgent.MAC;
  goog.testing.events.setEventClientXY_(contextmenu, opt_coords);
  return goog.testing.events.fireBrowserEvent(contextmenu);
};


/**
 * Simulates a mousedown, contextmenu, and the mouseup on the given event
 * target, with the right mouse button.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Mouse position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @return {boolean} The returnValue of the sequence: false if preventDefault()
 *     was called on any of the events, true otherwise.
 */
goog.testing.events.fireContextMenuSequence = function(target, opt_coords) {
  'use strict';
  const props = goog.userAgent.MAC ? {ctrlKey: true} : {};
  const button = (goog.userAgent.MAC && goog.userAgent.WEBKIT) ?
      goog.events.BrowserEvent.MouseButton.LEFT :
      goog.events.BrowserEvent.MouseButton.RIGHT;

  let result =
      goog.testing.events.fireMouseDownEvent(target, button, opt_coords, props);
  if (goog.userAgent.WINDOWS) {
    // All browsers are consistent on Windows.
    result = goog.testing.events.eagerAnd_(
        result,
        goog.testing.events.fireMouseUpEvent(target, button, opt_coords),
        goog.testing.events.fireContextMenuEvent(target, opt_coords));
  } else {
    result = goog.testing.events.eagerAnd_(
        result, goog.testing.events.fireContextMenuEvent(target, opt_coords));

    // GECKO on Mac and Linux always fires the mouseup after the contextmenu.

    // WEBKIT is really weird.
    //
    // On Linux, it sometimes fires mouseup, but most of the time doesn't.
    // It's really hard to reproduce consistently. I think there's some
    // internal race condition. If contextmenu is preventDefaulted, then
    // mouseup always fires.
    //
    // On Mac, it always fires mouseup and then fires a click.
    result = goog.testing.events.eagerAnd_(
        result,
        goog.testing.events.fireMouseUpEvent(
            target, button, opt_coords, props));

    if (goog.userAgent.WEBKIT && goog.userAgent.MAC) {
      result = goog.testing.events.eagerAnd_(
          result,
          goog.testing.events.fireClickEvent(
              target, button, opt_coords, props));
    }
  }
  return result;
};


/**
 * Simulates a popstate event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {Object} state History state object.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.firePopStateEvent = function(target, state) {
  'use strict';
  const e = /** @type {!PopStateEvent} */ (/** @type {!Event} */ (
      new goog.testing.events.Event(goog.events.EventType.POPSTATE, target)));
  e.state = state;
  return goog.testing.events.fireBrowserEvent(e);
};


/**
 * Simulate a blur event on the given target.
 * @param {EventTarget} target The target for the event.
 * @return {boolean} The value returned by firing the blur browser event,
 *      which returns false iff 'preventDefault' was invoked.
 */
goog.testing.events.fireBlurEvent = function(target) {
  'use strict';
  const e = new goog.testing.events.Event(goog.events.EventType.BLUR, target);
  return goog.testing.events.fireBrowserEvent(e);
};


/**
 * Simulate a focus event on the given target.
 * @param {EventTarget} target The target for the event.
 * @return {boolean} The value returned by firing the focus browser event,
 *     which returns false iff 'preventDefault' was invoked.
 */
goog.testing.events.fireFocusEvent = function(target) {
  'use strict';
  const e = new goog.testing.events.Event(goog.events.EventType.FOCUS, target);
  return goog.testing.events.fireBrowserEvent(e);
};


/**
 * Simulate a focus-in event on the given target.
 * @param {!EventTarget} target The target for the event.
 * @return {boolean} The value returned by firing the focus-in browser event,
 *     which returns false iff 'preventDefault' was invoked.
 */
goog.testing.events.fireFocusInEvent = function(target) {
  'use strict';
  const e =
      new goog.testing.events.Event(goog.events.EventType.FOCUSIN, target);
  return goog.testing.events.fireBrowserEvent(e);
};


/**
 * Simulates an event's capturing and bubbling phases.
 * @param {Event} event A simulated native event. It will be wrapped in a
 *     normalized BrowserEvent and dispatched to Closure listeners on all
 *     ancestors of its target (inclusive).
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireBrowserEvent = function(event) {
  'use strict';
  event = /** @type {!goog.testing.events.Event} */ (event);

  event.returnValue_ = true;

  // generate a list of ancestors
  const ancestors = [];
  for (let current = event.target; current; current = current.parentNode) {
    ancestors.push(current);
  }

  // dispatch capturing listeners
  for (let j = ancestors.length - 1; j >= 0 && !event.propagationStopped_;
       j--) {
    goog.events.fireListeners(
        ancestors[j], event.type, true,
        new goog.events.BrowserEvent(event, ancestors[j]));
  }

  // dispatch bubbling listeners
  for (let j = 0; j < ancestors.length && !event.propagationStopped_; j++) {
    goog.events.fireListeners(
        ancestors[j], event.type, false,
        new goog.events.BrowserEvent(event, ancestors[j]));
  }

  return event.returnValue_;
};


/**
 * Simulates a touchstart event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Touch position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireTouchStartEvent = function(
    target, opt_coords, opt_eventProperties) {
  'use strict';
  // TODO: Support multi-touch events with array of coordinates.
  const touchstart =
      new goog.testing.events.Event(goog.events.EventType.TOUCHSTART, target);
  goog.testing.events.setEventClientXY_(touchstart, opt_coords);
  if (opt_eventProperties) {
    goog.object.extend(touchstart, opt_eventProperties);
  }
  return goog.testing.events.fireBrowserEvent(touchstart);
};


/**
 * Simulates a touchmove event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Touch position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireTouchMoveEvent = function(
    target, opt_coords, opt_eventProperties) {
  'use strict';
  // TODO: Support multi-touch events with array of coordinates.
  const touchmove =
      new goog.testing.events.Event(goog.events.EventType.TOUCHMOVE, target);
  goog.testing.events.setEventClientXY_(touchmove, opt_coords);
  if (opt_eventProperties) {
    goog.object.extend(touchmove, opt_eventProperties);
  }
  return goog.testing.events.fireBrowserEvent(touchmove);
};


/**
 * Simulates a touchend event on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Touch position. Defaults to event's
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the event: false if preventDefault() was
 *     called on it, true otherwise.
 */
goog.testing.events.fireTouchEndEvent = function(
    target, opt_coords, opt_eventProperties) {
  'use strict';
  // TODO: Support multi-touch events with array of coordinates.
  const touchend =
      new goog.testing.events.Event(goog.events.EventType.TOUCHEND, target);
  goog.testing.events.setEventClientXY_(touchend, opt_coords);
  if (opt_eventProperties) {
    goog.object.extend(touchend, opt_eventProperties);
  }
  return goog.testing.events.fireBrowserEvent(touchend);
};


/**
 * Simulates a simple touch sequence on the given target.
 * @param {EventTarget} target The target for the event.
 * @param {goog.math.Coordinate=} opt_coords Touch position. Defaults to event
 *     target's position (if available), otherwise (0, 0).
 * @param {Object=} opt_eventProperties Event properties to be mixed into the
 *     BrowserEvent.
 * @return {boolean} The returnValue of the sequence: false if preventDefault()
 *     was called on any of the events, true otherwise.
 */
goog.testing.events.fireTouchSequence = function(
    target, opt_coords, opt_eventProperties) {
  'use strict';
  // TODO: Support multi-touch events with array of coordinates.
  // Fire touchstart, touchmove, touchend then return the AND of the 2.
  return goog.testing.events.eagerAnd_(
      goog.testing.events.fireTouchStartEvent(
          target, opt_coords, opt_eventProperties),
      goog.testing.events.fireTouchEndEvent(
          target, opt_coords, opt_eventProperties));
};


/**
 * Mixins a listenable into the given object. This turns the object
 * into a goog.events.Listenable. This is useful, for example, when
 * you need to mock a implementation of listenable and still want it
 * to work with goog.events.
 * @param {!Object} obj The object to mixin into.
 */
goog.testing.events.mixinListenable = function(obj) {
  'use strict';
  const listenable = new goog.events.EventTarget();

  listenable.setTargetForTesting(obj);

  const listenablePrototype = goog.events.EventTarget.prototype;
  const disposablePrototype = goog.Disposable.prototype;
  for (let key in listenablePrototype) {
    if (listenablePrototype.hasOwnProperty(key) ||
        disposablePrototype.hasOwnProperty(key)) {
      const member = listenablePrototype[key];
      if (typeof member === 'function') {
        obj[key] = goog.bind(member, listenable);
      } else {
        obj[key] = member;
      }
    }
  }
};

/**
 * Returns the boolean AND of all parameters.
 *
 * Unlike directly using `&&`, using this function cannot employ
 * short-circuiting; all side effects of resolving parameters will occur before
 * entering the function body.
 *
 * @param {boolean} first
 * @param {...boolean} rest
 * @return {boolean}
 * @private
 */
goog.testing.events.eagerAnd_ = function(first, rest) {
  'use strict';
  for (let i = 1; i < arguments.length; i++) {
    first = first && arguments[i];
  }
  return first;
};