Vježbanje TDD-a učinkovito ide dalje od poznavanja Red-Green-Refactor ciklusa — uključuje poduzimanje malih koraka, pisanje pravih testova, pravilno obavljanje refactor koraka i primjenu prosudbe o tome kada se TDD primjenjuje. Kada se radi dobro, vodi dobrom dizajnu i visokokvalitetnom, dobro testiranom kodu.
Disciplinirani ciklus
1. RED — write ONE small failing test for the NEXT bit of behavior (run it, see it fail —
confirms the test works and the feature is missing)
2. GREEN — write the SIMPLEST code to pass (don't over-engineer; even "fake it" first)
3. REFACTOR — now improve the design (remove duplication, clean up) with tests as a safety net
→ SMALL steps; one behavior at a time; stay in short cycles.
