What are the differences between stubs and mocks in testing?

What are the differences between stubs and mocks in testing?

Stubs and mocks are both used in testing to isolate components, but they serve different purposes. Stubs provide predefined responses to calls made during the test, while mocks are used to verify interactions between components.

Can you give me an example of when to use a stub?

Sure! You might use a stub when you want to simulate a database call that returns a fixed set of data without actually hitting the database.

And what about mocks? When should I use them?

Mocks are useful when you want to ensure that a specific method was called with the correct parameters. For example, if you're testing a service that sends notifications, you can mock the notification service to verify that it was called.

Are there any tools that can help with stubs and mocks?

Yes, there are several tools like Mockito for Java, Sinon.js for JavaScript, and unittest.mock for Python that can help you create stubs and mocks easily.