Refactor Code

Analyze a file or class for refactoring opportunities including helper class extraction, helper method extraction, nested function extraction, and test factory creation.

Usage

• •/do-refactor-code <filepath> - Analyze a specific file
• •/do-refactor-code <filepath>:<classname> - Analyze a specific class

Instructions

1. •

   Read the target file:

   • •Parse $ARGUMENTS to extract filepath and optional class name
   • •Read the file contents
2. •

   Analyze for Helper Class Extraction opportunities: Look for signs that a class should be split:

   • •Methods that only operate on a subset of the class's fields
   • •Method name prefixes suggesting a separate concern (e.g., inventory_check, inventory_update)
   • •Large classes with distinct groups of related functionality

   Report findings like:

   code

   HELPER CLASS EXTRACTION OPPORTUNITIES:
   - Methods `check_inventory`, `update_inventory`, `reserve_stock` all operate on `inventory_levels` field
     → Consider extracting to `InventoryManager` class
   

3. •

   Analyze for Helper Method Extraction opportunities: Look for signs of duplicated code within a class:

   • •Similar code blocks appearing in multiple methods
   • •Object creation with repeated parameters
   • •Setup/teardown logic duplicated across methods

   Report findings like:

   code

   HELPER METHOD EXTRACTION OPPORTUNITIES:
   - Lines 45-52 and 78-85 both create DataProcessor with identical parameters
     → Extract to `_create_processor(datasets, output_format)` helper
   

4. •

   Analyze for Nested Function Extraction opportunities (Python): Look for functions defined inside other functions:

   • •Named def statements inside another def
   • •Closures that don't actually need enclosing scope

   Report findings like:

   code

   NESTED FUNCTION EXTRACTION OPPORTUNITIES:
   - `format_value` defined inside `process_data` at line 12
     → Extract to module-level `_format_value` helper
   

5. •

   Analyze for Test Factory opportunities (if test file): Look for repeated test object creation:

   • •Multiple tests creating similar objects with different values
   • •Complex object construction with many required fields

   Report findings like:

   code

   TEST FACTORY OPPORTUNITIES:
   - `Order` objects created in 5 tests with mostly identical fields
     → Create `make_order(**overrides)` factory function
   

6. •

   Analyze for Module to Package Extraction (Python, large files): Look for monolithic files that should be split:

   • •Files exceeding 500-1000 lines
   • •Distinct sections (constants, models, utilities, main logic)
   • •Multiple unrelated classes or function groups

   Report findings like:

   code

   MODULE TO PACKAGE EXTRACTION:
   - `pipeline.py` (1089 lines) contains distinct sections:
     • Constants (lines 667-688)
     • Data classes (lines 33-359)
     • Utility functions (lines 362-623)
     • Main class (lines 787-1089)
     → Split into `pipeline/` package with focused modules
   

7. •

   Present summary and ask user:

   code

   Found X refactoring opportunities:
   - N helper class extractions
   - M helper method extractions
   - O nested function extractions
   - P test factory opportunities
   - Q module to package extractions
   
   Which refactoring would you like to apply? (Enter number or 'all')
   

8. •

   Apply selected refactoring(s):

   • •For helper class extraction: Create new file with extracted class, update imports
   • •For helper method extraction: Add private method, replace duplicated code with calls
   • •For nested function extraction: Move to module/class level with _ prefix
   • •For test factories: Add factory function at module level, update test usages
   • •For module to package: Create package directory, split into submodules, create __init__.py with re-exports (see templates/package-init.py.template)
9. •

   Run validation:

   bash

   uv run ruff check <filepath> --fix
   uv run ruff format <filepath>
   uv run pytest <test_filepath> -v
   

Reference

• •refactoring-patterns.md - Detailed patterns and examples
• •templates/package-init.py.template - Template for package __init__.py re-exports

Important Notes

• •Always read the file before suggesting changes
• •Preserve existing functionality - refactoring should not change behavior
• •Follow project conventions (private methods use _ prefix in Python)
• •Run tests after each refactoring to verify correctness