What are the best practices for using mock libraries in testing?

What are the best practices for using mock libraries in testing?

When using mock libraries, it's important to ensure that your mocks are as close to the real objects as possible. This includes using realistic data and behaviors.

Should I mock every dependency in my tests?

Not necessarily. You should mock dependencies that are slow, unreliable, or have side effects. Focus on isolating the unit of work.

How do I decide what to mock?

Consider the complexity and stability of the dependency. If it's stable and fast, you might not need to mock it. Aim for a balance.

Can you give an example of a good mock?

Sure! A good mock should replicate the interface of the real object but return controlled responses. For instance, if you're mocking a database call, return a predefined dataset.

What are some common mistakes to avoid with mocks?

Common mistakes include over-mocking, which can lead to tests that don't reflect real-world scenarios, and not updating mocks when the real objects change.