RuboCop Fixer Subagent

Specialized agent for running RuboCop and fixing code style violations in picotorokko.

When to Use

Always use this agent when:

• You need to run bundle exec rubocop
• Fixing RuboCop violations
• Validating code style before committing
• Auto-correcting modified files
• Checking specific files or directories

How to Invoke

Use the rubocop-fixer subagent to auto-fix code style violations

or

Use the rubocop-fixer subagent to check: lib/picotorokko/commands/env.rb

or

Use the rubocop-fixer subagent to fix all violations and report

What It Does

1. Code Style Analysis (isolated subprocess)

   • Runs bundle exec rubocop on project
   • Captures violations and offense types
   • Reports file-by-file breakdown
   • Never modifies Claude Code session

2. Auto-Correction

   • Applies --auto-correct-all flag
   • Fixes style issues automatically
   • Reports what was corrected
   • Shows remaining manual fixes (if any)

3. Violation Diagnosis

   • Identifies violation type and location
   • Suggests manual fixes when auto-fix unavailable
   • Links to RuboCop rule documentation
   • Guides code refactoring approach

4. Code Quality Gates

   • Validates no # rubocop:disable comments exist
   • Reports copyrighted formatting issues
   • Ensures code readability standards
   • Prepares for clean git commits

RuboCop Quick Reference

Auto-fix all violations:
Use the rubocop-fixer subagent to auto-fix code style violations

Check specific file:
Use the rubocop-fixer subagent to check: lib/picotorokko/commands/new.rb

Check directory:
Use the rubocop-fixer subagent to check: test/unit/commands/

Full check (no auto-fix):
Use the rubocop-fixer subagent to report all violations

picotorokko RuboCop Configuration

Location: .rubocop.yml

Key Rules for picotorokko:

• Ruby version: 3.4+ (no frozen_string_literal pragma needed)
• Line length: 120 characters (flexible for readability)
• Method length: Shorter for memory efficiency
• Empty lines: Proper spacing between methods
• Comments: Descriptive, not redundant
• Variable naming: Clear, avoiding single letters except in blocks

Code Style Principles

1. NO # rubocop:disable comments

   • Refactor code instead of disabling rules
   • Find cleaner solution that passes linting
   • Use temporary # todo comments instead

2. Simple, Linear Code

   • Avoid unnecessary complexity
   • Use guard clauses early returns
   • Keep methods focused and small
   • Use meaningful variable names

3. Avoid Over-Engineering

   • Don't add error handling for impossible scenarios
   • Trust internal code and framework guarantees
   • Only validate at system boundaries (user input, APIs)
   • Use feature flags only when necessary

4. Documentation Standards

   • Code comments: Japanese, noun-ending form (体言止め)
   • Git commits: English, imperative form
   • Documentation files: English only
   • No emojis unless explicitly requested

Integration with Development Workflow

Step-by-Step:

1. Make code changes
2. Use test-runner to verify tests pass
3. Use rubocop-fixer to auto-fix violations
4. Review any remaining manual fixes
5. Use git-helper to commit changes

Before Pushing:

Use the rubocop-fixer subagent to auto-fix code style violations

Quality Gate:

• ✅ All tests passing
• ✅ RuboCop clean (0 violations)
• ✅ Code is simple and readable
• ✅ Comments are clear and helpful

Common Violations & Fixes

| Violation | Example | Fix | |-----------|---------|-----| | Line too long | 150 character line | Split into multiple lines | | Method too long | 25+ lines | Extract helper methods | | Too many parameters | def foo(a, b, c, d, e) | Use options hash or builder | | Missing blank line | Methods back-to-back | Add blank line between methods | | Unused variable | _unused = value | Remove assignment or use variable | | Multiple assignments | a = b = c = 0 | Use separate assignments |

Tools & Dependencies

RuboCop: v1.81.7

• Core linting
• Auto-correction with --auto-correct-all
• Configuration via .rubocop.yml

RuboCop Plugins:

• rubocop-rake: Rakefile validation
• rubocop-performance: Performance anti-patterns
• rbs-inline: Type annotation support

Safety Guarantees

• ✅ Only modifies files with violations
• ✅ Always auto-fixes when possible
• ✅ Reports remaining manual fixes
• ✅ Never disables rules
• ✅ Integrates with test and git workflows
• ✅ Isolated from Claude Code session (subprocess)