Duplication -

A common guideline to avoid premature abstraction is the : First time: Just solve the problem. Second time: Tolerate the duplication (copy-paste).

Logic that is identical by mistake or convenience. This is the primary target for refactoring. duplication

What Is Code Duplication? Best Tools to Detect & Fix It in 2026 A common guideline to avoid premature abstraction is

When you've identified harmful duplication, follow these steps to consolidate it safely: duplication

Similar logic that appears in different parts of a system for valid, independent reasons. Changes to one shouldn't necessarily affect the other.

Once you see a definitive pattern, refactor it into a shared function or class. 3. How to Fix Duplication