Test-Driven Development

Use this skill when implementing new features or fixing bugs.

Red-Green-Refactor Cycle

1. •Red: Write a failing test that defines the expected behavior
2. •Green: Write minimal code to make the test pass
3. •Refactor: Clean up while keeping tests green
4. •VERIFY: Actually run the code (not just tests)

Verification Checklist

After Green phase, ALWAYS:

# 1. Tests pass
pytest -x

# 2. Imports work
python -c "from my_project import *; print('ok')"

# 3. Actually run the code path you changed
my-project info  # or relevant command

# 4. Smoke tests pass
pytest tests/test_smoke.py -v

CRITICAL

Unit tests can be written to pass. They prove you wrote code that satisfies your test, NOT that the code actually works.

After implementing, you MUST:

• •Run the actual code path (not through tests)
• •Verify the output is correct
• •Check for warnings/errors

Example Usage

/tdd Add a function to validate email addresses

Then:

1. •Write test for valid email → RED (fails)
2. •Implement validation → GREEN (passes)
3. •Refactor if needed
4. •VERIFY: Run actual validation with real inputs