Mock

Mock Functions with jest.fn()

Learn how to create, configure, and inspect Jest mock functions to isolate units under test and verify how dependencies are called.

Mocking HTTP Requests

Learn how to mock network calls in Jest tests using axios/fetch stubs, interceptor libraries like nock and msw, and how to simulate error and timeout scenarios.

Mocking Modules with jest.mock()

Understand how jest.mock() replaces entire modules with automatic or manual mocks, and how to combine that with jest.requireActual for partial mocking.

Mock Servers

Postman Mock Servers simulate API responses from a collection's saved examples, letting frontend and backend teams work in parallel before the real API exists.