What problem does it solve? Writing and reviewing plain JavaScript (non-TypeScript) Node.js code often leads to inconsistent style, swallowed errors, unbounded retries, blocking I/O, and security vulnerabilities. This Skill provides a concrete, numbered rule set (JS-01 through JS-25) derived from production Node.js services so code reviews and refactors follow one consistent standard. ## Core Features & Use Cases - Strictness and style rules: const-first declarations, destructuring, async/await over raw Promises, CommonJS export patterns, and JSDoc for all public methods. - Error handling and performance: contextual error logging, bounded retries with backoff, Set/Map for O(1) lookups, single-pass hot-path algorithms, and streaming large I/O with pipeline. - Security checklist: bans eval/Function, innerHTML with user data, hardcoded secrets, Math.random for tokens, and unsafe NODE_TLS_REJECT_UNAUTHORIZED usage, with AbortController-based timeouts. - Use Case: When reviewing a Node.js service pull request, apply the vulnerability checklist to catch a writeFileSync blocking the event loop, an unbounded recursive retry, and an unmasked token in logs before merge. ## Quick Start Review my Node.js service code against the javascript-strict rules and list every violation with a fixed version.