code-simplifier

name	code-simplifier
description	Guide for simplifying and refining code after coding sessions. Use when cleaning up complex code, reviewing PRs for readability, or applying consistent refactoring patterns. Triggers on simplify code, refactor, clean up, code review, コード整理, リファクタ, 複雑さ削減, コードレビュー.
argument-hint	整理したいコードや PR、気になる複雑さ
user-invocable	true
license	CC BY-NC-SA 4.0
metadata	{"author":"yamapan (https://github.com/aktsmm)"}

Code Simplifier

A guide for simplifying and refining code while preserving functionality.

When to Use

• Refactor, simplify code, clean up, code review
• After completing a coding task or writing a logical chunk of code
• Cleaning up complex PRs before review
• Refactoring code for better readability and maintainability

Core Principles

1. Preserve Functionality

Never change what the code does - only how it does it.

• All original features, outputs, and behaviors must remain intact
• Test before and after to verify no regressions
• If unsure, ask before refactoring

2. Apply Project Standards

Follow established coding standards from project configuration (CLAUDE.md, .editorconfig, ESLint, etc.):

• Consistent import sorting and organization
• Preferred function styles (arrow vs function keyword)
• Explicit type annotations where required
• Component patterns and naming conventions

3. Enhance Clarity

Simplify code structure by:

• Reducing unnecessary complexity and nesting
• Eliminating redundant code and abstractions
• Improving readability through clear variable and function names
• Consolidating related logic
• Removing unnecessary comments that describe obvious code

Critical Rules:

• Avoid nested ternary operators - prefer switch statements or if/else chains
• Avoid overly compact one-liners - explicit code is often better
• Choose clarity over brevity

4. Maintain Balance

Avoid over-simplification that could:

• Reduce code clarity or maintainability
• Create overly clever solutions that are hard to understand
• Combine too many concerns into single functions
• Remove helpful abstractions that improve organization
• Make the code harder to debug or extend

5. Focus Scope

Only refine code that has been recently modified or touched, unless explicitly instructed to review a broader scope.

Refinement Process

1. Identify the recently modified code sections
2. Analyze for opportunities to improve elegance and consistency
3. Apply project-specific best practices and coding standards
4. Ensure all functionality remains unchanged
5. Verify the refined code is simpler and more maintainable
6. Document only significant changes that affect understanding

Refactoring Patterns

See references/refactoring-patterns.md for common patterns.

Quick Checklist

Before submitting refactored code:

• All tests pass
• No functionality changed
• Code follows project standards
• No nested ternaries introduced
• Variable names are clear and descriptive
• No unnecessary abstractions added
• Comments updated if logic changed
• Import statements organized

Example Usage

Trigger phrases:

• "Simplify this code"
• "Make this clearer"
• "Refine this implementation"
• "Clean up this function"
• "Review this PR for readability"

Workflow:

1. Write code → Complete feature
2. Run tests → Verify functionality
3. Apply code-simplifier → Improve clarity
4. Run tests again → Confirm no regressions
5. Submit PR → Ready for review

Done Criteria

• All tests pass after refactoring
• No functionality changed
• Code follows project standards
• No nested ternaries or overly complex one-liners