What is the difference between stubs and fakes in testing?

What is the difference between stubs and fakes in testing?

Stubs and fakes are both types of test doubles used in software testing. Stubs provide predefined responses to calls made during tests, while fakes have working implementations but are simplified versions of the real components.

Can you give me an example of each?

Sure! A stub might return a fixed value when a method is called, like returning '10' when a function asks for a user's age. A fake, on the other hand, could be a lightweight database that simulates the behavior of a real database but stores data in memory.

When should I use stubs instead of fakes?

Use stubs when you need to isolate the unit of work and control the responses it receives. Fakes are better when you want to test interactions with a simplified version of a real component.

Are there any downsides to using stubs or fakes?

Yes, over-reliance on stubs can lead to tests that don't accurately reflect real-world scenarios, while fakes can introduce complexity if they are too close to the real implementation.