test-driven-development

The red-green-refactor cycle in test-driven development means writing a failing test, implementing minimal code to pass it, and then refactoring for clarity. This workflow enforces immediate feedback to guide design and prevent regressions.

To start test-driven development, write a failing test that defines the desired behavior, implement the minimal code required to make it pass, and then refactor the implementation for clarity while keeping the test green.

Test-driven development in this workflow requires real tests rather than mocks to verify correct behavior. It applies to bug fixes and refactors across unit, integration, and system levels where actual outcomes must be validated.

Test-driven development guards code quality during refactoring by basing implementation on concrete test outcomes. Starting with failing tests provides early validation that catches regressions and encourages safer architecture changes.

Test-driven development works across unit, integration, and system levels to verify correct behavior before coding. It enforces the red-green-refactor cycle to ensure features and refactors are validated through real tests.

A test-first coding approach may not suit contexts where correct behavior cannot be clearly specified in advance or where rapid prototyping without regression guards is prioritized over enforced test-driven design and quality validation.