Node.js Rules

Manage Node.js environment variables properly — validate at startup, fail fast on missing required vars, use typed config objects, and never access process.env scattered through code.

Handle errors properly in Node.js — always catch promise rejections, use custom error classes, implement global error handlers, and never swallow errors silently.

All new Node.js projects must use ECMAScript modules (ESM) — set type: module in package.json, use import/export syntax, and handle the CJS interop correctly for legacy dependencies.

Apply essential security practices for Node.js applications — validate all input, prevent injection attacks, secure HTTP headers, manage secrets properly, and audit dependencies.