How do I mock dependencies in Express.js tests?

How do I mock dependencies in Express.js tests?

You can use libraries like Sinon or Jest to mock dependencies in your Express.js tests. Would you like a code example?

Yes, please provide a code example using Jest.

Sure! Here's a simple example:

const request = require('supertest');
const app = require('../app');
const User = require('../models/user');

jest.mock('../models/user');

describe('GET /users', () => {
  it('should return a list of users', async () => {
    User.find.mockResolvedValue([{ name: 'John Doe' }]);
    const response = await request(app).get('/users');
    expect(response.status).toBe(200);
    expect(response.body).toEqual([{ name: 'John Doe' }]);
  });
});

This mocks the User model's find method.

What if I want to mock an external API call?

You can use libraries like nock to mock HTTP requests. Would you like to see an example of that?