Avoid Code Duplication

          
            ## Guidelines for Avoiding Code Duplication

1. **DRY Principle (Don't Repeat Yourself):**

   - Write code once and reuse it instead of copying and pasting
   - Extract repeated code into functions, components, or utilities
   - Centralize common logic in shared modules
   - Use inheritance, composition, or mixins where appropriate

2. **Common Duplication Patterns to Avoid:**

   - Repeated validation logic
   - Duplicate UI components with minor variations
   - Copy-pasted utility functions
   - Similar API call handling
   - Redundant data transformation code
   - Repeated configuration settings

3. **Abstraction Strategies:**

   - Create utility functions for common operations
   - Build reusable components with props for variations
   - Use higher-order components or custom hooks for shared behavior
   - Implement services or helpers for repeated business logic
   - Create configuration files for repeated settings

4. **Balance Considerations:**

   - Avoid premature abstraction - don't over-engineer for anticipated duplication
   - Consider the "Rule of Three" - abstract after the third occurrence
   - Balance DRY principles against code readability and simplicity
   - Ensure abstractions actually reduce complexity rather than increasing it

5. **Code Review Focus:**

   - Identify patterns of duplication across the codebase
   - Look for opportunities to consolidate similar code
   - Check for inconsistent implementations of the same functionality
   - Review new code against existing utilities before accepting duplication

6. **Testing Implications:**
   - Consolidated code only needs to be tested once
   - Tests can serve as documentation for reusable code
   - Fewer code paths means more thorough test coverage

By avoiding code duplication, you'll create a more maintainable codebase that's easier to update, has fewer bugs, and promotes consistent behavior across your application.