Refactoring

What it does

This skill refactors Python and Java backend code to improve readability, performance, and maintainability. It provides automated analysis and suggestions for safe restructuring, migrations, and modernization of existing codebases. The tool supports renaming identifiers, extracting methods into separate functions, and splitting large classes into smaller, more focused components. It prioritizes safety by checking dependencies and ensuring tests pass throughout the refactoring process.

When to use it

• When a code block exceeds 20 lines and needs to be broken down for clarity.
• To eliminate duplicated code segments within your project.
• When a class becomes too large (over 500 lines) and difficult to manage.
• To improve the testability of code by isolating functionality into smaller units.
• When renaming identifiers across a codebase is required, ensuring all references are updated safely.

Key capabilities

• Safe Renaming: Renames identifiers while finding all references, identifying scope (module-local, package-wide, public API), checking dependencies, and verifying with tests. Includes updating docstrings, comments, configuration files, and tests.
• Method Extraction: Extracts code blocks into separate functions based on length, duplication, single purpose, and testability.
• Class Splitting: Splits large classes into focused components when they have multiple responsibilities or require excessive mocking for testing.

Example prompts

• "Refactor this function: [paste function code]"
• "Extract the order validation logic from the process_order function."
• "Rename the class OrderManager to OrderService and update all references."

Tips & gotchas

• The skill uses grep for finding references, which may have limitations depending on code complexity.
• Consider a deprecation period when refactoring public APIs to ensure smooth transitions.
• For class splitting, the skill suggests strategies but requires developer oversight and potentially manual adjustments after automated extraction.