Agent Skills: code-refactor

When to Use This Skill

| Use this skill when... | Use something else when... | |------------------------|---------------------------| | A file or directory has mixed side effects and business logic | Deduplicating code across files → /code:dry-consolidation | | Functions mutate state or parameters | Detecting code smells without fixing → /code:antipatterns | | Business logic is tangled with I/O or logging | Reviewing overall quality and architecture → /code:review | | Imperative loops can be replaced with map/filter/reduce | Large multi-phase refactor spanning 10+ files → /workflow:checkpoint-refactor | | Deep nesting obscures intent | |

Context

• Target path: !echo "$1"

Parameters

• $1: Required file path or directory to refactor

Your task

Delegate this task to the code-refactoring agent.

Use the Agent tool with subagent_type: code-refactoring to refactor the specified code. Pass all the context gathered above to the agent.

The code-refactoring agent should:

1. Identify refactoring opportunities — look for these FP code smells:

   • Side effects (mutation, I/O, logging) mixed into computation functions
   • Parameters or external state mutated in place
   • Imperative loops (for, while) that could be map, filter, reduce, or flatMap
   • Shared mutable state accessed across functions
   • Deep nesting where early returns or guard clauses would clarify intent
   • Business logic entangled with I/O at call sites
   • Duplicated transformation logic

2. Apply functional programming principles:

   • Pure functions: Extract computation into functions with no side effects — same input always produces same output
   • Immutability: Replace in-place mutation with data transformations (spread, map, Object.assign, structural copies)
   • Composition: Build complex behavior from small, focused, single-purpose functions
   • Higher-order functions: Replace imperative loops with map, filter, reduce, flatMap, find
   • Explicit effects: Push I/O, logging, and mutations to the outermost boundary; keep inner functions pure
   • Early returns / guard clauses: Validate preconditions at the top, return early to avoid deep nesting
   • DRY / KISS: Eliminate repetition; prefer the simplest shape that works

3. Preserve functionality:

   • Ensure all existing tests pass
   • Maintain the external API contract
   • No behavioral changes

4. Output the refactored code with clear structure

Provide the agent with:

• The target file or directory path
• The detected programming language
• Any style guide examples from the project

The agent has expertise in:

• Behavior-preserving code transformations
• Functional refactoring patterns
• Code smell detection and remediation
• Semantic code search for similar patterns