JavaScript Language Expertise

Overview

Idiomatic ES2022+ JavaScript on Node.js 22+ (or Bun): ES modules, async/await, JSDoc types checked by tsc, the built-in node: APIs, and a small tool set. Assumes the reader knows the language. The content is decision rules and the traps that survive review: a floating promise, == on mixed types, a lost this, JSON.parse output merged into an object (prototype pollution), a catch that swallows the error, a test runner that finds zero files and exits 0. TypeScript syntax is covered by loom-typescript.

Tooling

Use the package manager the repository's lockfile names. For new work prefer Bun: bun add, bun remove, bunx. Do not run npm or npx commands in this workflow.