Refactoring Legacy
Domain: Refactoring
🎯 Motivation
Legacy code cannot be rewritten overnight. Safe refactoring strategies — seeding tests, wrapping, and incremental extraction — let you improve it without freezing development.
📋 Concrete Example
Before touching a legacy InvoiceProcessor, write characterization tests recording its current outputs. Then use Extract Function to pull out calculate_total() with tests guarding behavior.
🔗 Analogy
Restoring a classic painting: you do not paint over it. You clean a small corner, check the result, and proceed section by section, preserving the original while bringing it back to life.