add mock

README.md

@@ -239,6 +239,16 @@ Read [iOS documentation](https://developers.google.com/identity/sign-in/ios/back
 
 Read [iOS documentation](https://developers.google.com/identity/sign-in/ios/offline-access) and [Android documentation](https://developers.google.com/identity/sign-in/android/offline-access) for more information
 
+## Jest module mock
+
+If you use Jest for testing, you may need to mock the functionality of this native module. This library ships with a Jest mock that you can add to the `setupFiles` array in the Jest config. By default, it behaves as if the calls were successful and returns mock user data.
+
+```
+"setupFiles": [
+ "./node_modules/react-native-google-signin/jest/RNGoogleSigninMock.js"
+],
+```
+
 ## Additional scopes
 
 The default requested scopes are `email` and `profile`.

jest/RNGoogleSigninMock.js

@@ -0,0 +1,26 @@
+const mockUserInfo = {
+  idToken: 'mockIdToken',
+  accessToken: null,
+  accessTokenExpirationDate: null, // DEPRECATED, on iOS it's a time interval since now in seconds, on Android it's always null
+  serverAuthCode: 'mockServerAuthCode',
+  scopes: [], // on iOS this is empty array if no additional scopes are defined
+  user: {
+    email: 'mockEmail',
+    id: 'mockId',
+    givenName: 'mockGivenName',
+    familyName: 'mockFamilyName',
+    photo: 'mockPhotoUtl',
+    name: 'mockFullName',
+  },
+};
+
+jest.mock('react-native-google-signin', () => ({
+  GoogleSignin: {
+    configure: jest.fn(),
+    hasPlayServices: jest.fn(() => Promise.resolve(true)),
+    signIn: jest.fn(() => Promise.resolve(mockUserInfo)),
+    signInSilently: jest.fn(() => Promise.resolve(mockUserInfo)),
+    revokeAccess: jest.fn(() => Promise.resolve(true)),
+    signOut: jest.fn(() => Promise.resolve(true)),
+  },
+}));