tdd

To start writing unit tests before production code, follow the red-green-refactor method: write a failing test, implement minimal code to pass, then refactor while keeping tests green. This test-first workflow ensures correct behavior and catches regressions early.

The red-green-refactor workflow is a test-driven development cycle where you write a failing test, verify the failure, implement minimal code to make it pass, and then refactor the code while keeping all tests green.

Apply test-driven development to API handlers and data transformations by writing explicit failing tests that clarify requirements first. Run mandatory verifications to confirm test failure before implementing the minimal logic needed to pass.

Verifying a test failure before implementing the feature is a mandatory step in test-driven development to ensure the test itself is valid and that the production code actually causes it to pass, preventing false positives.

Yes, test-driven development is specifically recommended for tasks involving algorithms, business logic, data transformations, and API handlers, using stage gating and refactoring to drive reliable code design and robust quality assurance.

Test-first development may not suit exploratory prototyping where requirements are undefined, as the methodology requires explicit failing tests and clear requirements before any production code implementation can begin.