Bug Fix En

Language: Always interact with the user in 日本語.

bug-fix-en

Prerequisites

• Claude Code environment
• git, gh CLI

Arguments

• Issue number (e.g., /bug-fix-en #42): Fetch bug report from GitHub Issue
• Issue URL (e.g., /bug-fix-en https://github.com/owner/repo/issues/42): Same as above
• Text (e.g., /bug-fix-en 500 error on login): Use text as bug report
• No arguments: Interview the user about symptoms

Phase 1: Bug Report Organization and Branch Creation

1. Retrieve bug report from arguments
   • Issue: Read body, comments, and labels via gh issue view
   • Text: Use as bug report
   • No arguments: Interview the user
2. Organize the following (confirm missing info with user):
   • Symptoms: What is happening
   • Expected behavior: What should happen
   • Reproduction steps: How to reproduce
   • Environment: Browser, OS, environment (production/staging/local)
   • Frequency: Always / sometimes / under specific conditions
3. Record the current branch as the base branch (PR merge target)
   • Run git branch --show-current and display to user: "Base branch: "
   • Retain this name until PR creation in Phase 4
4. Create a working branch
   • Issue: fix/#<issue-number> (e.g., fix/#42)
   • Text / no arguments: fix/<bug-summary> (e.g., fix/login-500-error)
5. Create tasks with TaskCreate

Phase 2: Root Cause Investigation

1. Reproduce — Follow reproduction steps. If not reproducible, ask user for more info
2. Identify impact scope — Search related code with Explore agent or Grep/Glob. Check related tests
3. Identify root cause — Pinpoint the root cause with code flow evidence. Report cause and fix plan to user for agreement

Phase 3: Fix Cycle

3-1: Create Regression Test

• Before fixing, create a test that reproduces the bug and confirm it fails

3-2: Fix

• Fix the bug with minimal changes

3-3: Verify

• Confirm regression test + all existing tests pass

3-4: Review

• Review the fix with the review agent

3-5: Improvement Cycle

• If review issues found -> fix -> re-review -> repeat until no issues

3-6: Format & Lint

• Run format/lint per project settings. Skip if no settings found

3-7: Commit

• Follow commit message conventions in CLAUDE.md

Phase 4: Pull Request

1. Create PR with gh pr create --base <base-branch>
   • Use the base branch recorded in Phase 1. Never fall back to main or master.
   • If unclear, check fork point with git log --oneline --graph HEAD...main
   • With Issue: Include Issue number in title, then link via gh pr edit <PR#> --add-issue <Issue URL> after creation (do not use Closes keyword)
   • PR body: Bug symptoms, cause, fix summary + manual checklist (see templates/pr-checklist.md)
2. Report fix summary to user

Rules

• Never fix by guessing. Identify the root cause before fixing
• Always write a regression test before fixing (test fails -> fix -> test passes)
• Keep fixes minimal. Never mix unrelated refactoring
• Always report cause and fix plan to user for agreement
• Always fix review issues at severity levels. For lower severity, fix only if clear benefit
• Track progress with TaskCreate/TaskUpdate