如何在 React Native jest 测试中模拟推送通知本机模块？

Question

使用模块时react-native-push-notification，我遇到了这个错误：

 FAIL  __tests__/index.android.js
  ? Test suite failed to run

    Invariant Violation: Native module cannot be null.

      at invariant (node_modules/fbjs/lib/invariant.js:44:15)
      at new NativeEventEmitter (node_modules/react-native/Libraries/EventEmitter/NativeEventEmitter.js:32:1)
      at Object.<anonymous> (node_modules/react-native/Libraries/PushNotificationIOS/PushNotificationIOS.js:18:29)
      at Object.get PushNotificationIOS [as PushNotificationIOS] (node_modules/react-native/Libraries/react-native/react-native.js:97:34)
      at Object.<anonymous> (node_modules/react-native-push-notification/component/index.ios.js:10:23)

我试图通过创建__mocks__/react-native.js并将此代码放入其中来模拟模块：

const rn = require('react-native')

jest.mock('PushNotificationIOS', () => ({
  addEventListener: jest.fn(),
  requestPermissions: jest.fn(),
  then: jest.fn()
}));

module.exports = rn

现在，我有这个错误：

 FAIL  __tests__/index.android.js
  ? Test suite failed to run

    TypeError: Cannot read property 'then' of null

      at Object.<anonymous>.Notifications.popInitialNotification (node_modules/react-native-push-notification/index.js:278:42)
      at Object.<anonymous>.Notifications.configure (node_modules/react-native-push-notification/index.js:93:6)
      at Object.<anonymous> (app/utils/localPushNotification.js:4:39)
      at Object.<anonymous> (app/actions/trip.js:5:28)

我如何以正确的方式完全模拟这个模块？

Answer 1

我PushNotificationIOS通过创建一个安装文件来模拟模块jest/setup.js：

jest.mock('PushNotificationIOS', () => {
  return {
    addEventListener: jest.fn(),
    requestPermissions: jest.fn(() => Promise.resolve()),
    getInitialNotification: jest.fn(() => Promise.resolve()),
  }
});

我已经配置了 jest 来运行这个设置文件，方法是将这一行添加到packages.json：

  "jest": {
    ...
    "setupFiles": ["./jest/setup.js"],
  }