test-driven-development

Test-driven development prevents regressions by enforcing a failing test before production code implementation, verifying minimal changes pass tests, and actively avoiding mock-only assertions or test-after validation.

A test-first workflow fixes bugs by requiring a failing test demonstrating the incorrect behavior, implementing the minimal fix to pass it, and confirming the test passes to prevent future regressions.

The red-green-refactor cycle in unit testing enforces TDD discipline by requiring a failing test, implementing minimal code to pass, and refactoring while keeping tests green to prevent accidental feature creep.

Test-after validation fails to ensure software quality because TDD actively discourages it as proof, mandating failing tests before production code implementation to prevent mock-only assertions and incomplete mocking.

You cannot use mock-only assertions to verify new features in TDD, as it actively discourages this anti-pattern alongside test-only production methods, requiring mandatory failing and passing verification for behavior updates.