test-driven-development

To start writing failing tests before implementation, follow the Red-Green-Refactor cycle by writing a failing test first, creating minimal code to pass it, and then refactoring. This test-first approach ensures code reliability and prevents bugs.

The London School TDD methodology is a test-first software development approach emphasizing mock-first strategies. It isolates the unit under test by mocking collaborators, ensuring rigorous code quality and preventing regressions when building new features or fixing bugs.

The Red-Green-Refactor cycle works by first writing a failing test for new features or bug fixes, then writing minimal implementation code to make it pass, and finally cleaning up the code through refactoring while ensuring the tests continue to pass.

Yes, you need to use mocking to isolate units when following this test-first approach. The methodology emphasizes the London School of TDD, advocating for mocking collaborators to strictly isolate the unit under test and ensure accurate code quality verification.

You should not avoid a test-first strategy for refactoring, as this methodology mandates it. It enforces a test-first approach for all software development tasks, including new features, bug fixes, and refactoring, to strictly prevent regressions and maintain code quality.