test-driven-development

Test-driven development starts by writing a failing test that describes the behavior you want, then writing minimal production code to pass it. This red-green-refactor cycle ensures every line of code is backed by a test that validates actual behavior, preventing bugs and catching regressions early.

Test-driven development catches issues before they reach production by requiring failing tests first. Writing tests for edge cases and error conditions before implementation ensures comprehensive coverage and builds confidence that your code handles real-world scenarios correctly.

The red-green-refactor discipline in test-driven development lets you refactor with confidence. Since your tests already validate behavior, you can safely restructure code knowing tests will catch any regressions or broken functionality introduced during refactoring.

Yes, test-driven development applies to bug fixes by writing a failing test that reproduces the bug, then writing code to fix it. This ensures the bug doesn't reoccur and creates a regression test that catches the issue if it emerges again.

Writing tests first clarifies what behavior you need to build and validates that your implementation actually works. Tests written after code often miss edge cases and fail to catch regressions, while test-first development ensures every feature is thoroughly verified from the start.

Test-driven development guides you through implementing new features and behavior changes by writing failing tests for each behavior first, then adding minimal code to pass them. This applies consistently across feature development, bug fixes, and refactors using the same red-green-refactor cycle.