tdd

Test-driven development requires writing a failing test before implementation, then writing production code to pass it, and finally refactoring. This enforces the RED-GREEN-REFACTOR cycle to prevent regressions and ensure code quality.

The RED-GREEN-REFACTOR cycle is a test-driven development process where you first write a failing test (RED), implement code to make it pass (GREEN), then refactor the code while keeping tests green for better quality.

Fix bugs using TDD by first writing a test that reproduces the bug and fails, then implementing the fix to make it pass. This discipline prevents regressions and ensures the underlying issue is resolved.

Test-driven development fails when skipping the failing test step because it undermines discipline and allows rationalizations that compromise code quality. Verifying the test fails first ensures it actually validates the production code.

You cannot refactor before tests pass in test-driven development. The methodology requires a passing test (GREEN) before any refactoring begins, ensuring structural improvements do not alter behavior or introduce regressions.

You need test-driven development for software implementation when you want to prevent regressions and enforce code quality discipline. It ensures every feature is validated by failing tests before production code is written.