Safe Code Refactoring

Context

!git status --short 2>/dev/null !git stash list 2>/dev/null

---

Refactoring Process

Step 1: Analyze — Identify Code Smells

Read the target code and identify issues from this list:

• Long Method/Function (>40 lines): Extract smaller, focused functions
• Deep Nesting (>3 levels): Use early returns, guard clauses, or extract methods
• Code Duplication: Extract shared logic into reusable functions
• God Class/Module: Split into focused, single-responsibility modules
• Feature Envy: Move logic to the class/module that owns the data
• Primitive Obsession: Replace related primitives with a proper type/struct/class
• Long Parameter List (>4 params): Use an options/config object or builder pattern
• Dead Code: Remove unused functions, imports, variables, and commented-out code
• Magic Numbers/Strings: Extract into named constants
• Inconsistent Naming: Align with project conventions
• Missing Abstractions: Introduce interfaces/traits where concrete types are overused
• Tight Coupling: Introduce dependency injection or interface boundaries

Step 2: Plan — Define the Refactoring Strategy

For each identified issue:

1. Name the specific refactoring technique (Extract Method, Move Function, Introduce Parameter Object, etc.)
2. Describe the before and after state
3. Assess the risk (High/Medium/Low) — does it touch public API? Does it cross module boundaries?
4. List affected files

Present the plan to the user before executing.

Step 3: Verify — Check for Existing Tests

• Find all tests that cover the code being refactored
• Run them to establish a green baseline
• If no tests exist, flag this as a risk and recommend writing tests first

Step 4: Execute — Apply Changes

• Make one refactoring change at a time
• After each change, verify:
  • The code still compiles/parses
  • Existing tests still pass
  • No new linting errors
• If a change breaks something, revert it immediately

Step 5: Validate — Final Checks

• Run the full test suite for the affected area
• Verify no regressions via git diff
• Ensure the refactored code is actually simpler/cleaner than before
• If it isn't, consider reverting — refactoring should reduce complexity, not just move it

---

Rules

• Never change behavior — refactoring is about structure, not features
• Never skip tests — if tests don't exist, say so and suggest writing them first
• Small steps — one technique per commit if possible
• Respect scope — don't refactor code outside the requested area
• Keep the diff minimal — don't reformat untouched code