This article explains the differences and appropriate use cases of Mock, Dummy, Spy, Stub, and Fake test doubles in PHP unit testing, providing clear code examples to help developers write effective and maintainable tests.
The article explains how continuous testing provides rapid feedback and balanced test coverage, introduces contract testing and test doubles to decouple service dependencies, describes the consumer‑driven contract testing approach with Pact, and outlines scenarios where Pact is appropriate or unsuitable.
The article explains why mocking external components you don’t control can introduce maintenance problems, such as hidden bugs and upgrade difficulties, and suggests using real implementations, library‑provided fakes, or wrapper classes instead, while offering code examples and practical guidance.
The article explains the different types of test doubles—Dumb, Fake, Stub, and Mock—provides guidelines on when to prefer real implementations, discusses the drawbacks of overusing Stubs and Mocks, and offers practical advice for writing and maintaining Fakes in software testing.
