Feature Development Skill

Trigger

• Keywords: develop feature, implement, write code, verify, precommit, refactor, simplify

When NOT to Use

• Just want to understand code (use Explore)
• Review code only (use codex-code-review)
• Review documents only (use doc-review)
• Pure test-only tasks without feature changes (use /codex-test-review directly)

Prohibited Actions

❌ git add | git commit | git push — per @rules/git-workflow.md

This skill implements features but does not commit. /precommit-fast and /precommit are quality gates only. To commit, the user must invoke /smart-commit --execute separately.

Workflow

Requirements → Design → Implement → Test + Review → Precommit Gate → Doc Sync
                │          │            │                  │               │
                ▼          ▼            ▼                  ▼               ▼
           /codex-     /codex-    /verify              /precommit-fast  /update-docs
           architect   implement  /codex-test-review   (or /precommit)  /create-request --update
                                  /codex-review-fast

Commands

Phase	Command	Description
Design	/codex-architect	Get architecture advice
Implement	/codex-implement	Codex writes code
Test: Run	/verify	Run tests (lint → typecheck → unit → integration)
Test: Review	/codex-test-review	Mandatory — review test sufficiency (5 dimensions)
Test: Generate	/codex-test-gen	Generate unit tests for gaps
Test: Integration	/post-dev-test	Write missing integration/e2e tests
Review	/codex-review-fast	Code review (auto-loop)
Precommit	/precommit-fast	lint + test (auto-loop canonical path)
Precommit (full)	/precommit	lint + typecheck + test (important PRs)
Doc Sync	/update-docs	Sync docs with code
Doc Sync	/create-request --update	Update request progress
Refactor	/simplify	Final refactoring

Test + Review Phase (Detail)

This is the core of feature-dev — ensuring sufficient test coverage before code review.

Step 1: Run existing tests

/verify → all tests pass?
  Yes → Step 2
  No → fix failures → re-run /verify

Step 2: Test adequacy review (mandatory for code changes)

/codex-test-review → ✅ Tests sufficient?
  Yes → Step 3
  No → close gaps (Step 2a) → /codex-test-review --continue

Step 2a: Gap closure

Gap Type	Remediation Command
Unit test missing/insufficient	/codex-test-gen → write tests → /verify
Integration/E2E missing	/post-dev-test → write tests → /verify

Step 3: Code review (auto-loop)

/codex-review-fast → ✅ Ready?
  Yes → Precommit Gate
  No → fix issues → re-run /codex-review-fast (auto-loop)

Freshness rule

If code changes after the latest ✅ Tests sufficient gate (e.g., fixes from code review), rerun /verify then /codex-test-review --continue before proceeding to precommit gate.

Testing Requirements

Follow @rules/testing.md for conventions (AAA, naming, evidence model). Follow @rules/testing-project.md for project-specific overrides (directories, runner, adequacy mode).

Change Type	Test Requirements
New Service/Provider	Must have corresponding unit test
Modify existing logic	Existing tests pass + new logic tested
Bug fix	Must add regression test
New API endpoint	Integration test required
Cross-service change	E2E test required

Test File Mapping

Use project convention from @rules/testing-project.md. If no override is defined, follow ecosystem defaults:

Source Pattern	Test Pattern
src/<module>/	test/unit/<module>/ or test/<module>/
scripts/<name>.sh	test/scripts/<name>.test.js
skills/<name>/SKILL.md	test/commands/<name>.test.js
commands/<name>.md	test/commands/<name>.test.js

Output

• Implemented feature code + tests
• Test adequacy gate: ✅ Tests sufficient
• Review gate: ✅ Ready
• Precommit results: ✅ All Pass

Verification Checklist

• All tests pass (/verify)
• Test adequacy reviewed (/codex-test-review)
• Code review passed (/codex-review-fast ✅ Ready)
• Precommit passed (/precommit-fast ✅ All Pass)
• No git add/commit/push executed

Doc Sync (after precommit Pass)

⚠️ Auto-triggered by @rules/auto-loop.md — behavior-layer rule, not hook-enforced.

Only when change maps to a feature under docs/features/. Target detection uses 3-level fallback — see /update-docs for algorithm details.

precommit Pass
  → Locate feature docs (see /update-docs 3-level fallback)
  → /update-docs docs/features/<feature>/2-tech-spec.md
  → /create-request --update docs/features/<feature>/requests/<date>-<title>.md
  → /codex-review-doc (per updated file)
  → Safety valve: new code diff? → back to review loop (see /update-docs)

Review Loop

MUST re-review after fix until PASS (per @rules/auto-loop.md)

Review → Issues found → Fix → Re-review → ... → ✅ Pass → Next step

Examples

Input: Implement a fee calculation method
Action: /codex-architect → /codex-implement → /verify → /codex-test-review → /codex-review-fast → /precommit-fast

Input: This code needs refactoring
Action: /simplify → /verify → /codex-test-review → /codex-review-fast → /precommit-fast

Input: Feature dev, continue (resuming work)
Action: Check git status → identify remaining tasks → continue from current phase