Agent-skills-standard javascript-language

Modern JavaScript (ES2022+) patterns for clean, maintainable code. Use when working with modern JavaScript features like optional chaining, nullish coalescing, or ESM. (triggers: **/*.js, **/*.mjs, **/*.cjs, const, let, arrow, async, await, promise, destructuring, spread, class)

install

source · Clone the upstream repo

git clone https://github.com/HoangNguyen0403/agent-skills-standard

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/HoangNguyen0403/agent-skills-standard "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/javascript/javascript-language" ~/.claude/skills/hoangnguyen0403-agent-skills-standard-javascript-language && rm -rf "$T"

manifest: skills/javascript/javascript-language/SKILL.md

source content

JavaScript Language Patterns

Priority: P0 (CRITICAL)

Implementation Guidelines

Variables: const default. let if needed. No var — block scope only.
Functionality: Use Arrow Functions
for callbacks/inlines; Function Declaration
for core logic.
Async Logic: Use async/await with try/catch and Promise.all() for parallel operations. ESM import/export only. No Callbacks — promisify everything.
Modern Syntax: Use Destructuring, Spread (...), Optional Chain ?. and Nullish ?? coalescing.
String Handling: Use Template Literals
(backticks) for interpolation and multi-line strings.
Data Collections: Prefer map
, filter
, and reduce
over imperative
```
for
```
loops.
Modules: Standardize on ESM import/export; use Named Exports over Default.
Encapsulation: Leverage #private
class fields for encapsulation.
Error States: Throw new Error()
with descriptive messages; never throw strings.

Anti-Patterns

No var — Block scope only.
No
==
: Strict
```
===
```
.
No
new Object()
: Use literals
```
{}
```
.
No Callbacks: Promisify everything.
No Mutation: Immutability first.

Code & Reference

See references/REFERENCE.md for modern syntax, async patterns, private fields, and functional programming examples.