Package-level reference for debug on npm — namespace pattern, DEBUG env enable, browser vs Node, and production wrapping.
Package-level reference for form-data on npm — file uploads, streaming, headers, and the modern FormData web standard alternative.
Package-level reference for helmet on npm — default headers, CSP customization, per-route overrides, HSTS, and v7→v8 migration.
Package-level reference for lodash on npm — modular imports, ES2020+ replacements, lodash/fp, debounce/throttle, and the honest 'you might not need this' framing.
Package-level reference for node-fetch on npm — v2 (CJS) vs v3 (ESM), why Node 18+ built-in fetch obviates it, and migration paths.
Package-level reference for openai on npm — Chat Completions, the Responses API, streaming, tool calls, structured outputs, embeddings, and the v4→v5 migration.
Package-level reference for qs on npm — nested objects, arrays, allowDots, prototype-pollution history, and URLSearchParams comparison.
Package-level reference for uuid on npm — v4 random, v5 namespace, v7 sortable, ESM-only since v9, and namespace pattern.
Package-level reference for ws on npm — client/server, broadcast, heartbeat, compression, and security pitfalls.
Package-level reference for yargs on npm — command builders, middleware, prototype-pollution history, and alternatives like commander.
Astro is a multi-page, content-first web framework with an islands architecture — server-render Markdown, MDX, and component pages to static HTML, then hydrate interactive widgets selectively with React, Vue, Svelte, or Solid.
Rust-based all-in-one linter and formatter for JS/TS/JSON/CSS/GraphQL. Single binary, single config, 10-100x faster than ESLint+Prettier.
Bun is a fast all-in-one JavaScript runtime, package manager, bundler, and test runner written in Zig — a drop-in replacement for Node.js and npm with built-in TypeScript and JSX support.
Apply ANSI colours, backgrounds, and text styles to terminal output in Node.js using Chalk's chainable API, plus comparisons with picocolors and patterns for building polished CLI UX.
Build full-featured Node.js CLIs with positional arguments, typed options, subcommands, auto-generated help, lifecycle hooks, and a distributable bin in package.json.
Parse, format, manipulate, compare, and convert timezones for dates in JavaScript using Day.js — a 2 kB Moment-compatible alternative with a plugin-based architecture.
Deno is a secure, modern JavaScript and TypeScript runtime built on V8 with permission-based sandboxing, built-in TypeScript, a curated standard library on JSR, and a complete toolchain (fmt, lint, test, bench, compile).
Load configuration and secrets from .env files into process.env at startup, with multi-environment files, variable expansion, schema validation, and Node 20.6+ built-in --env-file alternatives.
Fastify is a high-performance Node.js web framework with schema-driven validation, plugin encapsulation, hooks, decorators, and built-in Pino logging — covering routes, plugins, hooks, error handling, and production hardening.
Node.js file system module — the three APIs (callback, sync, promises), reading and writing files, directory operations, watchers, atomic writes, and path module pairing.
Node.js streams — Readable, Writable, Duplex, and Transform, the modern pipeline() API, backpressure, async iterators, Web Streams interop, and patterns for piping files, HTTP bodies, and gzip compression.
Cross-browser end-to-end test runner from Microsoft with auto-waiting, role-based selectors, trace viewer, and codegen.
Schema-first ORM for Node.js with auto-generated typed client, declarative migrations, relations, transactions, and seeding — for PostgreSQL, MySQL, SQLite, MongoDB, and more.
Foundational React patterns — function components, JSX, props, hooks (useState, useEffect, useRef, useContext), list rendering, and form handling — with TypeScript throughout.
TypeScript-first runtime validation library. Define schemas, validate inputs, infer static types — works at API boundaries, env config, forms, and tRPC.
Cheat sheets for Node.js modules from the npm registry — HTTP clients, validation, CLI builders, utility libraries, and more.
Node.js runtime, package managers, async patterns, array methods, and frontend tooling — a complete JavaScript reference for the command line and the browser.
JavaScript arrays have ~30 built-in methods for transforming, searching, and reducing data. Covers mutation, non-mutation, search, boolean, iteration, and static methods with real examples.
async/await syntax, error handling, parallel execution with Promise.all, sequential vs parallel loops, top-level await, AbortController, and common mistakes.
JavaScript error handling with try/catch/finally, built-in error types, custom error classes, error chaining with cause (ES2022), async errors, and practical patterns like result objects.
The standard JavaScript/TypeScript linter. Covers flat config (v9), legacy .eslintrc, running, rules, plugins, TypeScript integration, VS Code, and pre-commit hooks.
The browser and Node 18+ built-in HTTP client that returns Promises. Covers GET/POST/PUT/DELETE, headers, error handling, streaming, AbortController, uploads, credentials, and CORS.
Install Node.js on Windows, macOS, and Linux using winget, Homebrew, apt, nvm, Volta, or fnm. Covers version managers, LTS vs current, and verifying your install.
CommonJS vs ES Modules in Node.js — syntax, how Node chooses the module system, dynamic import, top-level await, CJS/ESM interop, and common pitfalls.
How to use the Node.js runtime — REPL, running scripts, CLI flags, ESM vs CJS modules, built-in node: modules, the process object, and modern globals like fetch and structuredClone.
Complete npm reference — installing packages, scripts, workspaces, package.json anatomy, audit, publish, link, lockfiles, and registry configuration.
Run npm package binaries without global installs using npx. Covers resolution order, version pinning, --yes, --no-install, npm exec, scaffolders, and cache management.
Complete reference for the Node.js package manifest — name, version, scripts, dependencies, exports, workspaces, and the packageManager field for Corepack.
Fast, disk-efficient package manager using a content-addressable store and hard-links. Covers install, add, remove, scripts, dlx, exec, the pnpm store, and workspaces.
Opinionated code formatter for JS/TS/CSS/HTML/JSON/Markdown. Covers config options, .prettierignore, VS Code integration, ESLint compatibility, lint-staged, and CI usage.
JavaScript Promises represent the eventual completion or failure of an async operation. Covers states, chaining, combinators, callback conversion, AbortController, and common anti-patterns.
JavaScript has built-in RegExp support (ES2018+ with named groups, lookbehind, dotAll). Covers literal syntax, flags, character classes, methods, named captures, and common patterns.
Next-generation frontend build tool using native ES modules for near-instant dev server startup and Rollup for production bundles. Covers setup, config, HMR, env vars, assets, CSS, and plugins.
Vite-native unit test framework with a Jest-compatible API. Covers setup, writing tests, matchers, mocking, timers, async testing, coverage, and UI mode.
Yarn is a fast, deterministic package manager from Meta. Covers Yarn Classic (v1) vs Yarn Berry (v4), install, add, remove, workspaces, Plug'n'Play, and migration tips.
A reference hub for programming languages and their ecosystems — Python, JavaScript, and TypeScript, with package managers, runtimes, and tooling.
Static typing for JavaScript — tsconfig reference, the full type system, generics, utility types, narrowing, and common compiler errors explained.
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