tdd

Start TDD Workflow

Begin Test-Driven Development (TDD) workflow for a new feature or bug fix.

Usage

/tdd

Workflow

🔴 RED Phase - Write Failing Tests

1. Understand the requirement:

   • What behavior needs to be implemented?
   • What are the expected inputs and outputs?
   • What edge cases need to be handled?

2. Write the test FIRST:

   # Example: tests/test_feature.py
   
   def test_feature_handles_valid_input():
       # GIVEN: Valid input
       input_data = {"key": "value"}
   
       # WHEN: Function is called
       result = my_feature(input_data)
   
       # THEN: Returns expected output
       assert result == expected_output
   

3. Run the test to verify it FAILS:

   pytest tests/test_feature.py::test_feature_handles_valid_input -xvs
   

   Expected: Test should FAIL with clear error message. Why: Proves the test is actually testing something and isn't a false positive.

4. Commit the failing test:

   git add tests/test_feature.py
   git commit -m "test: add failing test for feature X"
   

🟢 GREEN Phase - Implement Minimal Code

1. Write the simplest code to make test pass:

   # src/module/feature.py
   
   def my_feature(input_data):
       # Minimal implementation
       return expected_output
   

2. Run the test to verify it PASSES:

   pytest tests/test_feature.py::test_feature_handles_valid_input -xvs
   

   Expected: Test should PASS.

3. Run all tests to ensure no regressions:

   make test-unit
   

4. Commit the implementation:

   git add src/module/feature.py
   git commit -m "feat: implement feature X
   
   Adds minimal implementation to make test pass.
   
   Closes #123"
   

♻️ REFACTOR Phase - Improve Code Quality

1. Refactor for better design:
   • Extract functions for clarity
   • Add type hints
   • Improve variable names
   • Add docstrings
   • Remove duplication