tdd.md

Start a TDD (Test-Driven Development) cycle for the requested feature or function.

Process

1. Red Phase - Write a Failing Test

• Ask what behavior to implement if not specified.
• Identify the test framework in use (Jest, Vitest, pytest, Go testing).
• Write a single focused test that describes the desired behavior.
• Run the test to confirm it fails for the right reason.
• The test should fail because the feature does not exist yet, not because of a syntax error.

2. Green Phase - Make It Pass

• Write the minimum code necessary to make the test pass.
• Do not optimize or generalize yet. Just make it work.
• Run the test to confirm it passes.
• If it fails, fix the implementation, not the test.

3. Refactor Phase - Clean Up

• Look for duplication, unclear naming, or unnecessary complexity.
• Extract helper functions if logic is repeated.
• Improve variable and function names for clarity.
• Run the full test suite to verify nothing broke.

4. Repeat

• Ask what the next behavior to implement is.
• Start another Red-Green-Refactor cycle.

Rules

• Each cycle targets exactly one behavior. Do not batch multiple behaviors.
• Tests must be independent and not depend on execution order.
• Use descriptive test names: should <expected behavior> when <condition>.
• Mock external dependencies (HTTP, database, filesystem) at boundaries.
• Keep each cycle under 5 minutes of implementation time.
• If a cycle takes longer, the scope is too large. Break it down.