# Modern Javascript Patterns

> Master ES6+ features including async/await, destructuring, spread operators, arrow functions, promises, modules, iterators, generators, and functional programming patterns for writing clean, efficient JavaScript code. Use when refactoring legacy code, implementing modern patterns, or optimizing JavaScript applications.

Source: https://skillsagentes.com/skills/wshobson/agents/modern-javascript-patterns
Repository: https://github.com/wshobson/agents
Author: wshobson
License: MIT
Updated: hace 2 meses
Context cost: 80 tok installed, 547 tok once triggered, 5.7k tok with every bundled file
Bundle: 3 files, 22 KB
Permissions requested: none declared

## Install

```bash
npx -y skills add wshobson/agents --skill modern-javascript-patterns --agent claude-code
```

## What it does

- Aplica patrones ES6+ como async/await, destructuring, spread, arrow functions, promesas, módulos, iteradores y generadores
- Refactoriza código legacy hacia sintaxis moderna
- Aplica buenas prácticas: const por defecto, template literals, optional chaining, nullish coalescing
- Detecta anti-patrones comunes (this, promesas, memory leaks) usando referencias detalladas

## Use it when

- Refactorizar JavaScript legacy a sintaxis moderna
- Implementar patrones de programación funcional
- Migrar de callbacks a Promises/async-await
- Optimizar rendimiento o construir aplicaciones web modernas

## What triggers it

- "Refactoriza este código JavaScript a ES6+"
- "Convierte estos callbacks a async/await"
- "Ayúdame a aplicar patrones funcionales en este módulo"

## Files

- SKILL.md — 2 KB
- references/advanced-patterns.md — 10 KB
- references/details.md — 10 KB

## SKILL.md

Reproduced verbatim from wshobson/agents under MIT. This section is the upstream document and is in English.

# 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).

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Skills Agentes — https://skillsagentes.com/skills/wshobson/agents/modern-javascript-patterns