Tdd Go

Parsing Rules

• Unchecked test: - [ ] test: ...
• Checked test: - [x] test: ... # passed @...
• Next test: First unchecked test from top
• Metadata: Extract file: and name: from parentheses

Instructions

Step 1: Select Next Test

1. Read plan.md
2. Find first - [ ] test: line
3. Extract metadata: file: (test file path) and name: (test function name)
4. Only process this one test (do not skip ahead)

Step 2: RED Phase

1. Check if test already exists in the file
2. If not, write the simplest failing test:

   def test_example():
       assert False  # Intentionally failing
   

3. Run test to confirm it fails:

   pytest tests/test_file.py::test_name -v
   # or
   cargo test test_name
   

4. Verify failure message is clear

Step 3: GREEN Phase

1. Implement minimum code to make test pass
2. Hardcoding is acceptable initially
3. Run test to confirm it passes:

   pytest tests/test_file.py::test_name -v
   

4. Run all tests to ensure nothing broke:

   pytest -q
   # or
   cargo test
   

Step 4: REFACTOR Phase

1. Only refactor if all tests pass
2. Improve structure without changing behavior:
   • Extract methods/functions
   • Rename variables
   • Remove duplication
   • Improve naming
3. Behavior must remain identical
4. Run all tests after each refactoring step:

   pytest -q
   

Step 5: Update plan.md

1. Mark test as completed:

   - [x] test: <description> (file: <path>, name: <name>) # passed @2026-01-28 <commit:abcd1234>
   

2. Use actual date and commit hash (or placeholder if not committed yet)

Integration Points

Works With

• implementer agent: Automatically called for code implementation
• verifier agent: Validates test execution and results
• plan.md: Source of truth for test queue

Workflow

User: "go"
  → tdd-go skill
    → Read plan.md (select next test)
    → RED: Write failing test
    → implementer agent (GREEN: minimal code)
    → REFACTOR: Structure improvement
    → verifier agent (validate all tests)
    → Update plan.md

TDD Principles

RED Phase

• Write the simplest failing test
• Test should clearly express the requirement
• Failure message should be informative
• One test at a time

GREEN Phase

• Write minimum code to pass
• Hardcoding is fine initially
• No premature optimization
• Just make it pass

REFACTOR Phase

• Only when all tests pass
• Improve structure, not behavior
• Small, incremental changes
• Run tests after each change
• Behavior must remain identical

Example Workflow

Input (plan.md)

## Tests
- [ ] test: CLI report works on temp dir (file: tests/test_cli_smoke.py, name: test_cli_report_smoke)

RED Phase

# tests/test_cli_smoke.py
def test_cli_report_smoke():
    result = run_cli_report()
    assert result.status == "ok"  # This will fail

GREEN Phase

# src/inventory_master/cli.py
def report_command():
    return {"status": "ok"}  # Minimal implementation

REFACTOR Phase

# Extract to function, improve naming
def generate_report(root: Path) -> ReportResult:
    return ReportResult(status="ok", files=0)

Output (plan.md updated)

## Tests
- [x] test: CLI report works on temp dir (file: tests/test_cli_smoke.py, name: test_cli_report_smoke) # passed @2026-01-28 <commit:abcd1234>

Output Format

ExecSummary

• Test selected from plan.md
• Phase completed (RED/GREEN/REFACTOR)
• Files modified
• Test status

Diff Summary

• Minimal changes only
• Test file changes
• Implementation changes
• plan.md update

Verification Commands

# Run specific test
pytest tests/test_file.py::test_name -v

# Run all tests
pytest -q

# Check coverage (if applicable)
pytest --cov=src --cov-report=term-missing

Restrictions

Must Follow

• One test at a time: Never skip ahead
• All tests pass: Before refactoring
• Behavior preservation: Refactoring must not change behavior
• plan.md is SoT: Always read from plan.md, update after completion

Commit Discipline

• Structural commits: Refactoring only (no behavior change)
  • Example: [Structural] Extract method for clarity
• Behavioral commits: New functionality or bug fixes
  • Example: [Behavioral] Add report command to pass test
• Never mix: Structural and behavioral in same commit

Troubleshooting

Test Already Exists

• If test exists but fails → proceed to GREEN phase
• If test exists and passes → check plan.md, may need to mark as complete

All Tests Fail After Change

• Revert to last green state
• Make smaller incremental changes
• Run tests more frequently

plan.md Format Error

• Verify format matches expected structure
• Check for proper - [ ] or - [x] syntax
• Ensure metadata (file:, name:) is present

Additional Resources

• For TDD methodology: Kent Beck's "Test-Driven Development"
• For implementer details: .cursor/agents/implementer.md
• For verification: .cursor/agents/verifier.md
• For workflow examples: docs/AGENTS_AND_SKILLS_GUIDE.md