modern-javascript-patterns

SKILL.md

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

Use const by default: Only use let when reassignment is needed

Prefer arrow functions: Especially for callbacks

Use template literals: Instead of string concatenation

Destructure objects and arrays: For cleaner code

Use async/await: Instead of Promise chains

Avoid mutating data: Use spread operator and array methods

Use optional chaining: Prevent "Cannot read property of undefined"

Use nullish coalescing: For default values

Prefer array methods: Over traditional loops

Use modules: For better code organization

Write pure functions: Easier to test and reason about

Use meaningful variable names: Self-documenting code

Keep functions small: Single responsibility principle

Handle errors properly: Use try/catch with async/await

Use strict mode: 'use strict' for better error catching

For common pitfalls (this binding, promise anti-patterns, memory leaks), see references/advanced-patterns.md.