Bug Fix Skill

Trigger

• Keywords: bug, issue, fix, error, broken, failing

When NOT to Use

• New feature development (use feature-dev)
• Just want to understand code (use code-explore)

Workflow

Investigate ──→ Locate ──→ Fix ──→ Test ──→ Review
  │               │        │        │        │
  ▼               ▼        ▼        ▼        ▼
gh issue        Grep     Edit    Write    /codex-review-fast
/git-inv        Read     tests   /verify  /precommit

Phase 1: Investigation

Source	Action
GitHub Issue	gh issue view <number>
Error message	Grep("error message")
Code history	/git-investigate

Output root cause analysis:

• Problem location: src/xxx.ts:123
• Root cause:
• Impact scope:

Phase 2: Fix

Principle	Description
Minimal changes	Only modify what is necessary
No new issues	Confirm changes don't affect other features

Phase 3: Add Tests ⚠️

Bug fixes must have tests at the corresponding level

Bug Type	Required	Recommended
Logic error	Unit	-
Service issue	Unit	Integration
API issue	Integration	E2E
User flow	E2E	-

Detailed guide: testing-guide.md

Phase 4: Review

/verify              # Run tests
/codex-review-fast   # Code review
/codex-test-review   # Test review
/precommit           # Pre-commit checks

Review Loop

⚠️ Follow @rules/auto-loop.md

Fix → Review → Issues found → Fix again → ... → ✅ Pass

Output

## Bug Fix Report
- **Root cause**: <analysis>
- **Fix**: <description of changes>
- **Regression test**: <test result>
- **Gate**: ✅ Fixed / ⛔ Needs further investigation

Verification

• Issue confirmed fixed
• Tests at corresponding level written
• All tests passing
• Code review passed (Gate ✅)

Examples

Input: Fix issue #123 - calculation error
Action: gh issue view → locate → fix → write Unit Test → /verify → /codex-review-fast

Input: API returning 500 error
Action: Grep error → read code → fix → write Integration Test → /verify → /codex-review-fast