Alex Kotliarskyi ea7c5ab04b Add mock for BackHandler
Reviewed By: fkgozali

Differential Revision: D4861901

fbshipit-source-id: b1b74e63731328d2235bf86794aa481a8275ed8c
2017-04-11 12:25:38 -07:00

53 lines
1.2 KiB
JavaScript

/**
* Copyright (c) 2013-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
*/
'use strict';
const _backPressSubscriptions = new Set();
const BackHandler = {
exitApp: jest.fn(),
addEventListener: function (
eventName: BackPressEventName,
handler: Function
): {remove: () => void} {
_backPressSubscriptions.add(handler);
return {
remove: () => BackHandler.removeEventListener(eventName, handler),
};
},
removeEventListener: function(
eventName: BackPressEventName,
handler: Function
): void {
_backPressSubscriptions.delete(handler);
},
mockPressBack: function() {
let invokeDefault = true;
const subscriptions = [..._backPressSubscriptions].reverse();
for (let i = 0; i < subscriptions.length; ++i) {
if (subscriptions[i]()) {
invokeDefault = false;
break;
}
}
if (invokeDefault) {
BackHandler.exitApp();
}
},
};
module.exports = BackHandler;