At praktisere TDD effektivt går ud over at kende Red-Green-Refactor-cyklussen — det handler om at tage små skridt, skrive de rigtige tests, udføre refactor-trinnet korrekt, og vurdere, hvornår TDD er passende. Når det gøres godt, driver det et god design og højkvalitets, veltestaet kode.
Den disciplinerede cyklus
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.
