/code - TDD Implementation

NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST.

Violation → delete the code, write the test, then rewrite.

Announce at Start

Before writing any code, declare:

Starting TDD RGRC cycle. Every code change begins with a failing test.

Rationalization Counters

Excuse	Counter
"This is too simple for TDD"	Simple changes hide regressions. One test line prevents hours of debug
"I'll add tests later"	"Later" never comes. Test debt compounds with interest
"This is just a refactor"	Refactors without tests are the #1 cause of silent regressions
"Existing tests already cover"	If they do, Red phase will confirm it. Run it
"Testing this would be too slow"	A slow test is faster than a production bug

Input

Implementation description: $1 (required, prompt if empty) Flags: --frontend, --principles, --storybook

Flag	Loads
--frontend	applying-frontend-patterns
--principles	applying-code-principles
--storybook	integrating-storybook

SOW Context

[@../skills/lib/sow-resolution.md]

Skills & Agents

• Agent: test-generator (TDD test generation, standalone background)
• Agent: e2e-test-generator (E2E test generation, conditional background)
• Agent: code-quality-reviewer (review gate, post-RGRC)
• Skill: orchestrating-workflows (RGRC cycle)
• Hook: gates (completion gate + review enforcement, auto-iteration)

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Scope Guard

After reading SOW, check Phase file counts. If any Phase has Files ≥ 5, stop and ask user to split via /think before proceeding. If no SOW exists and $1 implies ≥ 5 files, suggest running /think first.

Execution

1. SOW Context: detect and read SOW/spec → Scope Guard
2. Spawn test-gen as standalone background agent (subagent_type: test-generator, run_in_background: true)
3. Receive test results via TaskOutput
4. RGRC cycle with ralph-loop --max-iterations 10 auto-iteration
5. Review Gate: spawn code-quality-reviewer (skip for /fix)
6. E2E Phase (conditional)
7. Quality Gates

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Spec Evolution

During implementation, new requirements may be discovered (edge cases, error handling, integration concerns). When this happens:

1. Update Spec first: Add T-NNN to the Test Scenarios table in spec.md
2. Then write the test: Reference the new T-NNN in the test name/comment
3. Never add tests without a Spec trace: Every test must map to a T-NNN

This keeps the Spec as the single source of truth. The test-quality-evaluator agent uses T-NNN mappings to compute coverage scores.

E2E Phase (Conditional)

After Review Gate, before Quality Gates. Skip entirely if any condition fails.

Conditions (all must pass, evaluate in order, skip on first fail)

#	Check	How	On fail
1	Spec has Type: e2e scenarios	Grep Spec Test Scenarios table	skip (silent)
2	agent-browser installed	which agent-browser	skip + advisory
3	Dev server detected in package.json	Match dev, start:dev, start scripts	skip + advisory
4	Dev server running (user confirms)	AskUserQuestion: "Dev server at {url}?"	skip + advisory

Dev Server Detection

From package.json scripts (same pattern as /feature Phase 4.5):

Priority	Script name pattern	Default URL
1	dev, start:dev	http://localhost:5173
2	start	http://localhost:3000
3	storybook, storybook:dev	http://localhost:6006

Extract port from script value if specified (--port, -p, PORT=).

Execution

Agent(subagent_type: "e2e-test-generator",
      prompt: "spec_path: <path>\ndev_server_url: <url>",
      run_in_background: true)

Results: generated tests run and pass → proceed. Failures → advisory (do not block Quality Gates).

Quality Gates

After RGRC cycle, verify each AC is met (implemented + tested). Skip if no SOW.

If Spec exists, run via Agent(subagent_type: "test-quality-evaluator") in background. Score ≥70 required. See orchestrating-workflows for gate details.

Error Handling

Error	Action
test-gen background timeout	Leader generates tests directly
test-gen produces 0 tests	Verify spec exists, ask user
Ralph-loop stalls	Stop loop, fix manually
Quality gates fail	Fix issues before commit
Evaluator score <70	Fix uncovered/excess/intent issues
Evaluator timeout	Skip gate, log warning
Spec not found	Create spec.md or ask user
agent-browser crash	Skip E2E, advisory, continue
Dev server unreachable	Skip E2E, advisory, continue
E2E tests fail	Advisory (do not block)