react-native/Libraries/Utilities/__mocks__/BackHandler.js

51 lines
1.1 KiB
JavaScript

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @format
*/
'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;