Node.js

When to Use

• Real-time Apps: Chat, Gaming, Collaboration (WebSockets).
• API Servers: High concurrency with non-blocking I/O.
• Tooling: The foundation of modern frontend toolchains (Vite, Next.js).

Quick Start (Native Features)

// Native Test Runner (No Jest needed)
import { test, assert } from "node:test";

test("synchronous passing test", (t) => {
  assert.strictEqual(1, 1);
});

// Native WebSocket
const ws = new WebSocket("ws://example.com/socket");
ws.onopen = () => console.log("Connected");

Core Concepts

Event Loop

Streams

Native APIs (2025)

fetch

test

watch

.env

Best Practices (2025)

• Use

  node:test

  : Drop Jest/Mocha for simple projects.
• Use

  node --env-file

  : Drop

  dotenv

  dependency.
• Use Async/Await: Callbacks are dead. Long live Promises.

• Don't block the Event Loop: Don't run Crypto or Image processing on the main thread. Use Worker Threads.
• Don't use

  require

  : New projects should use ESM (

  import

  ).

References

• Node.js Documentation