tdd

Test-driven development for feature development is guided through a structured red-green-refactor workflow. It enforces writing public-interface tests first to validate user-visible behavior, followed by minimal implementation per cycle to incrementally build reliable features.

The red-green-refactor workflow in TDD is a cycle of writing a failing test, implementing minimal code to pass it, and then refactoring. This process separates behavior from internal structure, ensuring incremental design and reducing regressions.

Writing TDD tests for public behavior involves focusing assertions on user-visible interfaces rather than internal module structure. The workflow guides you to validate actual functional output first, ensuring tests remain robust against internal refactoring.

TDD is suitable for both bug fixes and learning environments. It guides developers through a strict test-first cycle to reproduce and resolve bugs reliably, while also serving as a structured practice method for mastering incremental implementation.

The best way to start a TDD cycle is by writing a tracer bullet, which is one failing test for a public interface. You then implement the minimal code required to pass that test, establishing a clear separation of behavior from internal structure.

Test-driven development may be avoided when internal implementation details are highly volatile or user-visible public interfaces are undefined. Since TDD enforces writing public-interface tests first, lacking a clear behavioral target limits its effectiveness for incremental design.