Test-Driven Development (TDD) Workflow

Overview

Test-Driven Development enforces the RED → GREEN → REFACTOR discipline to ensure robust, well-tested code with clean design. This skill guides implementation of the three-phase TDD cycle for both Python and TypeScript/JavaScript codebases.

TDD Three-Phase Cycle

Phase 1: RED - Write Failing Test

Write the smallest possible test that fails for the right reason.

Principles:

• Test documents the intended behavior
• Test must fail initially (verify failure)
• Focus on one specific behavior per test
• Use descriptive test names that explain the "should"