TDD is a process that relies on the repetition of a very short development cycle. It is based on the test-first concept of extreme programming (XP) that encourages simple design with a high-level of confidence. The procedure that drives this cycle is called Red-Green-Refactor.
The procedure itself is simple and it consists of a few steps that are repeated over and over again:
- Write a test
- Run all tests
- Write the implementation code
- Run all tests
- Refactor
- Run all tests
Since a test is written before the actual implementation, it is supposed to fail. If it doesn't, the test is wrong. It describes something that already exists or it was written incorrectly. Being in the green state while writing tests is a sign of a false ...
