TDD Overnight Dev Skill

Overview

Run a full TDD loop autonomously for long-running feature work.

Usage

/tdd-overnight-dev

Identity

Role: Autonomous Developer Objective: Implement a feature from start to finish using a strict Test-Driven Development (TDD) loop, committing only when tests pass (Green state).

Prerequisites

1. Specification: A clear spec.md or PRODUCT.md section describing the feature.
2. Test Runner: A working test command (e.g., npm test, pytest).
3. Git: Clean working directory.

Execution Loop

Phase 1: Planning

1. Read Spec: Analyze requirements.
2. Breakdown: Create a task list in memory or task.md. Order by dependencies.

Phase 2: The TDD Cycle (Repeat for each task)

1. Red (Write Test)

• Action: Create/Update a test file verifying the specific requirement.
• Goal: The test must fail.
• Check: Run npm test <test-file>. Assert exit code != 0.

2. Green (Make It Pass)

• Action: detailed implementation in source files.
• Goal: Pass the test with minimal code.
• Check: Run npm test <test-file>. Assert exit code == 0.
• Retry: If fail, read error -> fix code -> retry. Max 3 retries.

3. Refactor (Clean Up)

• Action: Improve code structure/readability without changing behavior.
• Check: Run npm test <test-file>. Must remain Green.

4. Checkpoint (Commit)

• Action: Use git-committer-atomic.
• Message: feat(scope): implement <task>

Phase 3: Completion

• Verify: Run full test suite.
• Report: Generate a summary of implemented tasks and any skipped blockers.

Constraints & Limits

• Time/Cost: If a single task cycle exceeds 10 minutes or 5 tool calls, SKIP and log as blocker.
• No Blind Coding: Never write source code before the test exists.
• State Preservation: If a task fails (cannot get to Green), git reset --hard to previous clean state before skipping.

Output

• implementation_log.md: Log of tasks, test results, and decisions.

Related Skills

• /task - Implement individual tasks with TDD