High Cohesion

          
            ## Guidelines for High Cohesion

Cohesion refers to the degree to which elements within a module belong together. High cohesion means that the methods and properties of a class, component, or module are closely related and focused on a single purpose.

1. **Core Principles:**

   - Each module, component, or function should have a single, well-defined purpose
   - Related functionality should be grouped together
   - Unrelated functionality should be separated
   - Elements that change together should stay together
   - Elements that don't change together should be separated

2. **Signs of Good Cohesion:**

   - Clear, focused component and function names that describe a single responsibility
   - Methods in a class that operate on the same data
   - Functions that work toward a common goal
   - Easy-to-write unit tests that don't require excessive mocking
   - Components that can be explained in a single sentence

3. **Types of Cohesion (from highest to lowest):**

   - **Functional Cohesion:** All elements contribute to a single, well-defined task
   - **Sequential Cohesion:** Output from one element serves as input to another
   - **Communicational Cohesion:** Elements operate on the same data
   - **Procedural Cohesion:** Elements follow a specified sequence of execution
   - **Temporal Cohesion:** Elements are related by when they're executed
   - **Logical Cohesion:** Elements perform similar functions but are otherwise unrelated
   - **Coincidental Cohesion:** Elements have no meaningful relationship (avoid this)

4. **Implementation Strategies:**

   - Apply the Single Responsibility Principle
   - Create utility modules that focus on specific domains
   - Use component composition instead of large monolithic components
   - Organize code around business domains or features
   - Extract unrelated functionality into separate modules

5. **Benefits of High Cohesion:**

   - Improved maintainability and readability
   - Better testability
   - Easier debugging
   - Enhanced reusability
   - Simpler code navigation

6. **Practical Applications:**
   - Split large files into smaller, more focused ones
   - Create helper/utility files organized by domain
   - Separate UI, business logic, and data access concerns
   - Group related components in directories with clear purposes
   - Use hooks to extract and isolate related functionality

By maintaining high cohesion throughout your codebase, you create a more organized, maintainable, and understandable system that's easier to extend and modify over time.