I am trying to write unit tests using jest and trying to mock firebase-admin. Here is my application code:
import logger from './logger';
import admin from 'firebase-admin';
class NotificationService {
constructor() {
admin.initializeApp({
credential: admin.credential.cert({
projectId: 'FCM_PROJECT_ID',
privateKey: 'FCM_PRIVATE_KEY'
clientEmail: 'FCM_CLIENT_EMAIL'
}),
});
}
public async send(message: TokenMessage): Promise<ApiResponse<string>> {
try {
await admin.messaging().send(message)
} catch (e) {
logger.error(e);
}
}
}
I am trying to mock the code like below:
jest.mock('firebase-admin');
But it is erroring out with:
firebase_admin_1.default.messaging is not a function
What is the solution?
Issue: not mocking the member variables and methods(messaging, send) of firebase-admin.
Fix:
jest.mock('firebase-admin', () => ({
messaging: jest.fn().mockImplementation(() => {
return {
send: jest
.fn()
.mockReturnValue('message_id'),
};
}),
}));
Note: You would probably need to mock credential and initializeApp as well:
jest.mock('firebase-admin', () => ({
credential: {
cert: jest.fn(),
},
initializeApp: jest.fn(),
messaging: jest.fn().mockImplementation(() => {
return {
send: jest
.fn()
.mockReturnValue('message_id'),
};
}),
}));