javascript
Installation
SKILL.md
JavaScript
Conventions and rules for idiomatic JavaScript. TypeScript builds on these — when working in TS, apply both this skill and typescript.
Rules (always apply)
| Rule | File |
|---|---|
| Use JavaScript general conventions (naming, const/let, destructuring, template literals) | rules/js-general-conventions.md |
Prefer explicit context (params) over implicit this |
rules/prefer-explicit-context-over-this.md |
Do not use barrel files (index.js/index.ts re-exports) |
rules/no-barrel-files.md |
Avoid intermediate arrays on hot paths (filter().map() chains) |
rules/avoid-intermediate-arrays.md |
undefined for absence, null for API/external contracts |
rules/null-undefined.md |
Read On Demand
- ECMAScript edition history (ES1 1997 → ES2025): see
references/ecmascript-history.md. Use when judging which edition first shipped a feature, what needs a polyfill on older runtimes, or which syntax is safe for a target environment.