test-driven-development

Start test-driven development by writing a failing test before any implementation, then write minimal code to pass the test, and finally refactor the code while keeping tests green.

The Red-Green-Refactor cycle is a test-driven development practice where you write a failing test, write minimal code to pass it, and then refactor the implementation to improve code quality without breaking functionality.

Writing tests after implementation often leads to poor code quality because it rationalizes existing design flaws rather than preventing regressions, whereas strict test-driven development forces better modular design by verifying test failures first.

Prevent testing anti-patterns during refactoring by adhering strictly to the test-driven development cycle, which identifies common rationalizations and ensures minimal code passes tests before improving maintainability.

Yes, applying test-driven development to existing software improves maintainability by enforcing strict verification of test failures before coding, preventing regressions, and guiding systematic refactoring of current implementations.