code

/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, output the declaration below verbatim.

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
"Red test doesn't need verification"	Untested Red = writing blind. Run it; confirm failure matches the intent

Input

• $ARGUMENTS holds the implementation description (required, prompt if empty)

Flags

Flag	Effect
--no-storybook	Disable Storybook auto-detection (default: auto-detect)

Auto-detects when project has Storybook + component file. See Storybook Phase.

SOW Context

See ${CLAUDE_SKILL_DIR}/../_lib/sow-resolution.md

Scope Guard

After reading OUTCOME.md and SOW, check (a) Phase file counts and (b) outcome alignment. If any Phase has Files ≥ 5, stop and ask user to split via /think before proceeding. If the implementation steps into Non-goals or conflicts with Constraints from OUTCOME.md, stop and confirm with user. If no SOW exists and $ARGUMENTS implies ≥ 5 files, suggest running /think first.

Target Languages

JS/TS is first-class. Rust / Go / Python work via generator-test framework detection. When detection fails, specify the test runner explicitly in the task prompt. Storybook/E2E phases auto-skip for non-JS/TS via their existing conditions. Quality Gates are language-agnostic (T-NNN coverage, gates hook per language pre/post-edit).

External References

Reference	When read	If not found / unclear
.claude/OUTCOME.md	Step 0 Outcome Anchor	Generate stub via /outcome
${CLAUDE_SKILL_DIR}/../_lib/sow-resolution.md	Step 1 SOW detect	No SOW state, apply Scope Guard inline only
${CLAUDE_SKILL_DIR}/references/csf3-patterns.md	Storybook Phase all conditions pass	Use minimal CSF3 stories format
/goal (optional)	Step 4 autonomous loop	gates auto-retry; manual otherwise
generator-test agent	Step 2 spawn	Error Handling: Leader generates tests directly
evaluator-test agent	Step 8 Quality Gates, Spec exists	Skip Test Quality gate
reviewer-readability agent	Step 5 Review Gate	Skip for /fix; continue with manual review

Notation

Symbol	Meaning	Usage
T-NNN	T-\d{3} three-digit zero-padded spec scenario ID (e.g. T-001)	Embed in test function name, describe/it string, or inline comment
TaskOutput	Synchronous receive from run_in_background: true spawn	Wait for completion before proceeding

Execution

Step	Action	Detail
0	Outcome Anchor	Read .claude/OUTCOME.md; if absent, generate the stub via /outcome
1	SOW Context	Detect and read SOW/spec → Scope Guard
2	Spawn generator-test	subagent_type: generator-test, run_in_background: true
3	Receive test results	TaskOutput (wait for completion before implementation)
4	RGRC cycle	gates auto-retry per Green; optional /goal wrapper. Condition pairs target with preserved invariants (e.g. "0 failures, no test deleted/skipped")
5	Review Gate	Spawn reviewer-readability (skip for /fix)
6	Storybook Phase	Conditional
7	E2E Phase	Conditional
8	Quality Gates	See use-workflow-code

Spec Evolution

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

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

evaluator-test uses T-NNN mappings to compute coverage and other quality metrics.

Storybook Phase (Conditional)

Conditions

All must pass, evaluated in order, skip on first fail.

#	Check	How	On fail
1	--no-storybook flag not set	Parse $ARGUMENTS	skip (silent)
2	Project has Storybook	.storybook/ exists OR @storybook/* in package.json deps	skip (silent)
3	Implementation includes component file(s)	.tsx/.jsx with PascalCase export in changed files	skip (silent)

Declare

When conditions match, announce before generating.

[auto-detect] Storybook detected + {File}.tsx appears to be a component.
Will generate {File}.stories.tsx. Opt out with --no-storybook.

Execution

For each detected component, generate {Component}.stories.tsx per ${CLAUDE_SKILL_DIR}/references/csf3-patterns.md. Source props from Spec's Component API section when present, otherwise infer from the component.

Existing Stories Handling

Option	Action
[O]	Overwrite existing file
[S]	Skip - keep existing
[M]	Merge - show diff, manual
[D]	Diff only - append new

E2E Phase (Conditional)

Conditions

All must pass, evaluated in order, skip on first fail.

#	Check	How	On fail
1	Spec has Type: e2e scenarios	ugrep 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

Detected from package.json scripts.

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

Quality Gates

Check	Condition	How
AC met	After RGRC	Manual (skip if no SOW)
Test Quality (per-metric)	Spec exists	evaluator-test agent
Iteration enforcement	Every Write/Edit/MultiEdit	gates hook (PostToolUse)

See use-workflow-code for invocation details.

Error Handling

Error	Action
generator-test timeout	Leader generates tests directly
generator-test produces 0 tests	Verify spec exists, ask user
/goal loop stalls	/goal clear, then fix manually
Quality gates fail	Fix issues before commit
Evaluator metric below threshold	Fix uncovered/excess/duplicate/granularity/intent issues
Evaluator timeout	Skip gate, log warning
Spec not found	Proceed without T-NNN trace, skip Test Quality gate (or ask user to create spec)
agent-browser crash	Skip E2E, advisory, continue
Dev server unreachable	Skip E2E, advisory, continue
E2E tests fail	Advisory (do not block)
Storybook phase error	Skip phase, advisory, continue