vcsdd-tdd

What

Runs the Red phase (Phase 2a): generates test cases for every requirement in the behavioral spec. Tests MUST FAIL before implementation begins. Records failure evidence.

When

Run after spec review gate (Phase 1c) passes. Requires active feature at phase 1c.

How

1. Read behavioral spec: extract all REQ-XXX requirements
2. Invoke vcsdd-builder agent to generate tests:
   • One test function per requirement minimum
   • Additional tests for each edge case in spec
   • Tests for error conditions and boundary values
3. Create test-case beads: one per test function, linked to corresponding REQ-XXX bead
4. Transition to 2a: this starts sprint N for the current implementation cycle (transitionPhase(feature, '2a'))
5. Run tests and verify they FAIL:

   npm test 2>&1 | tee .vcsdd/features/<name>/evidence/sprint-N-red-phase.log
   

6. Verify regression baseline: run existing tests separately to confirm they still pass
7. Record red phase evidence in the active sprint with explicit markers at the top of the log:

   new-feature-tests: FAIL
   regression-baseline: PASS
   

   For coverage-retrofit sprints (adding tests to already-implemented code):
   • Use coverage-retrofit: true instead of new-feature-tests: failing
   • Example:

     coverage-retrofit: true
     regression-baseline: PASS
     total-tests: 45
     new-tests-added: 3
     

8. Append the raw failing test output after those markers so the gate can prove both conditions
9. Display summary: sprint number, N tests generated, all failing as expected

CRITICAL: Red Phase Validation

If ANY new test passes before implementation, STOP. The test is invalid (it's testing the wrong thing or the implementation already exists). Fix the test first.

Examples

/vcsdd-tdd
/vcsdd-tdd --framework vitest    # specify test framework
/vcsdd-tdd --framework pytest