TDD: Test-Driven Development

🥷 Sub-agent orchestrated red-green-refactor, one acceptance criterion at a time.

Outcome Contract

• Outcome: Feature implemented with passing tests, verified through independent sub-agent perspectives and human review gates (mode-dependent: Full/Fast/Batch)
• Done when: All acceptance criteria (from input Issue, PRD, or confirmed in Step 1) pass their cycle; unified refactor complete; all tests GREEN
• Evidence: Tests turn GREEN per cycle; human approved scenario design and test code at each gate; final refactor passes full suite
• Output: Per-cycle results with test locations, test statistics, refactor summary, next step to /review

Core Principles

Behavior testing through public interfaces. Tests verify what the system does, not how. Code can change completely; tests should not.

Sub-agent independence. Sub-agents are independent (anti-patterns #34, #35); the shared re-read checklist lives in REFERENCE.md Sub-Agent Common.

Two-stage human review (recommended default). Each acceptance criterion passes through two synchronous gates — Scenario Review Gate (scenario design quality) and Test Code Review Gate (code quality and fidelity). Both gates are blocking; execution halts until the human responds. See Gate Modes — Fast and Batch are offered per-cycle, not hidden behind a user request.