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name: tdd description: Enforce test-driven development workflow. Use when implementing new features or fixing bugs — write the test first, then the implementation.

TDD Workflow

Follow this cycle for every change:

1. RED — Write a failing test

• Write the test BEFORE any implementation
• Test should describe the desired behavior
• Run the test — it MUST fail
• If it passes, the test is wrong or the feature already exists

2. GREEN — Make it pass

• Write the MINIMUM code to make the test pass
• Don't optimize, don't refactor, don't add extras
• Just make the test green

3. REFACTOR — Clean up

• Now improve the code
• Extract functions, rename variables, reduce duplication
• Run tests after each refactor — they must stay green

Rules

• Never write implementation before the test
• One test at a time
• Each test should test ONE behavior
• Use descriptive test names: "should return 404 when user not found"
• Don't test implementation details — test behavior