modern-javascript-patterns

# Modern JavaScript Patterns Comprehensive guide for mastering modern JavaScript (ES6+) features, functional programming patterns, and best practices for writing clean, maintainable, and performant code. ## When to Use This Skill - Refactoring legacy JavaScript to modern syntax - Implementing functional programming patterns - Optimizing JavaScript performance - Writing maintainable and readable code - Working with asynchronous operations - Building modern web applications - Migrating from callbacks to Promises/async-await - Implementing data transformation pipelines ## Detailed patterns and worked examples Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient. ## Best Practices 1. **Use const by default**: Only use let when reassignment is needed 2. **Prefer arrow functions**: Especially for callbacks 3. **Use template literals**: Instead of string concatenation 4. **Destructure objects and arrays**: For cleaner code 5. **Use async/await**: Instead of Promise chains 6. **Avoid mutating data**: Use spread operator and array methods 7. **Use optional chaining**: Prevent "Cannot read property of undefined" 8. **Use nullish coalescing**: For default values 9. **Prefer array methods**: Over traditional loops 10. **Use modules**: For better code organization 11. **Write pure functions**: Easier to test and reason about 12. **Use meaningful variable names**: Self-documenting code 13. **Keep functions small**: Single responsibility principle 14. **Handle errors properly**: Use try/catch with async/await 15. **Use strict mode**: `'use strict'` for better error catching For common pitfalls (this binding, promise anti-patterns, memory leaks), see [references/advanced-patterns.md](references/advanced-patterns.md).