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JavaScript Pro

Write, debug and refactor modern JavaScript with async patterns, ESM modules and Node.js APIs

Source Download skill
Repository
Jeffallan/claude-skills
Stars
12,176
Licence
MIT
Files
6 files

What it does

This skill gives an AI agent a specialist playbook for JavaScript work. Once installed, the agent writes code using modern ES2023+ syntax, async/await with explicit error handling, ES module conventions, and Node.js and browser APIs such as Fetch, Web Workers and fs/promises. It also loads reference notes on those topics when relevant and follows a workflow that runs a linter and Jest tests before finishing.

Great for

  • Developers building vanilla JavaScript or Node.js code who want consistent modern patterns
  • Teams wanting a reviewer that checks .js, .mjs or .cjs files for async error handling and correctness
  • Developers optimising browser or Node performance with Web Workers or streams

Skip it if

  • Projects that depend on CommonJS or TypeScript-only conventions, since the rules push ESM and forbid mixing module systems, which may clash with existing code
  • Users wanting quick throwaway scripts, because the workflow requires linting, 85%+ Jest coverage and bundle checks that add overhead

Try asking

  • “Refactor this callback-based Node script to use async/await with proper error handling”
  • “Review my fetch wrapper in src/api.mjs for unhandled promise rejections”
  • “Write a Web Worker that parses a large CSV without blocking the UI, with Jest tests”
  • “Explain why my ESM import fails when the package.json has type set to module”
Step-by-step guide: how to use JavaScript ProInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 6 original files, the MIT licence and an attribution note.

    javascript-pro.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip javascript-pro.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip javascript-pro.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • State your Node version and browser targets up front so the agent picks compatible syntax
  • Ask for a specific reference area (async, modules, browser APIs) to focus the guidance
  • Review generated code yourself, since the skill's rules are opinionated (e.g. no var, functional style) and may not match your codebase

What's inside

  • references/async-patterns.md
  • references/browser-apis.md
  • references/modern-syntax.md
  • references/modules.md
  • references/node-essentials.md
  • SKILL.md

Redistributed unmodified from Jeffallan/claude-skills under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.