What are mocks and how do I use them in integration tests?

What are mocks and how do I use them in integration tests?

Mocks are simulated objects that mimic the behavior of real objects in controlled ways. In integration tests, they help isolate the system under test by replacing dependencies with mock objects.

Can you give me an example of how to implement mocks in a test?

Sure! If you're using a testing framework like Jest, you can create a mock function using jest.fn(). Then, you can pass this mock to your function under test to verify interactions.

What are the benefits of using mocks in integration tests?

Using mocks can speed up tests, reduce flakiness, and allow you to test edge cases without relying on external systems.

Are there any downsides to using mocks?

Yes, overusing mocks can lead to tests that are too tightly coupled to implementation details, making them brittle and harder to maintain.