What is the difference between Mockito Mock and Spy?

What is the difference between Mockito Mock and Spy?

Mockito Mock creates a dummy object that simulates the behavior of a real object, while Spy wraps a real object to track interactions.

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

Use a Mock when you want to isolate the unit of work and don't need the actual implementation, like testing a service without hitting the database.

And when should I use a Spy?

Use a Spy when you want to test a real object but still need to verify interactions or modify behavior, like tracking method calls.

Are there any performance implications of using Mocks vs Spies?

Yes, Mocks can be faster since they don't involve real object behavior, while Spies may introduce overhead due to the real object's methods being called.

Can I use both Mock and Spy in the same test?

Yes, you can use both in the same test to isolate certain behaviors while still tracking interactions with real objects.