test-driven-development

The red-green-refactor workflow in test-driven development iterates code by writing a failing test, implementing minimal production code to pass it, then refactoring while keeping tests green.

To write failing tests before production code, define expected feature behavior with a unit test, run it to observe failure, then implement minimal code to pass.

Use test-first discipline for bug fixes by writing a failing test that reproduces the bug before changing production code, ensuring the fix resolves the specific defect.

Test-driven development works for refactoring existing software projects by maintaining green tests while restructuring code, ensuring minimal production code changes preserve functionality.

Writing minimal production code to pass unit testing in TDD prevents over-engineering, ensures every code path is test-covered, and strictly satisfies the failing test requirements.