modern-javascript-patterns

modern-javascript-patterns is a skill for Claude Code, Codex from punkadillo/figma-code-composer. It costs 64 tokens per session (461 once invoked), scanned A, a copy of modern-javascript-patterns, MIT.

A reference for modern JavaScript features and coding patterns, including promises, async and await, modules, and functional programming.

In plain words
What is it for?
Use it when refactoring older JavaScript, handling asynchronous work, transforming data, or writing modern web application code.
Why use it?
It helps replace older or repetitive JavaScript code with clearer patterns that are easier to maintain.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when refactoring older JavaScript, handling asynchronous work, transforming data, or writing modern web application code.

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Install with agentmods
npx agentmods add skills/punkadillo/figma-code-composer/modern-javascript-patterns
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add punkadillo/figma-code-composer --skill modern-javascript-patterns
Clone the repo
git clone --depth 1 https://github.com/punkadillo/figma-code-composer

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for modern-javascript-patterns

README.md
[![agentmods](https://agentmods.dev/badge/skills/punkadillo/figma-code-composer/modern-javascript-patterns.svg)](https://agentmods.dev/skills/punkadillo/figma-code-composer/modern-javascript-patterns)
Your own site
<a href="https://agentmods.dev/skills/punkadillo/figma-code-composer/modern-javascript-patterns"><img src="https://agentmods.dev/badge/skills/punkadillo/figma-code-composer/modern-javascript-patterns.svg" alt="Measured on agentmods" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 461 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00064 $0.00461
Opus 5 $0.00032 $0.00230
Sonnet 5 $0.00013 $0.00092
Haiku 4.5 $0.00006 $0.00046

Measured 4d ago against content hash 32e203b8d944, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

modern-javascript-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to modern-javascript-patterns — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.figma-pipeline/skills/modern-javascript-patterns/SKILL.md · 44 lines

What it actually says

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.

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 44 lines · 64 tokens per session scan A 32e203b8d944

Subscribe to this mod's changes

modern-javascript-patterns is a skill published in the GitHub repository punkadillo/figma-code-composer (3 stars, last pushed 19d ago), licensed MIT. It adds 64 tokens to every session and 461 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to modern-javascript-patterns, differing in 0 lines, and is treated as a copy.

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