Ethan Arrowood Ethan-Arrowood

Module 1 - Introduction to WebSockets

Resources:

Lesson 1 - Upgrading HTTP

This lesson will discuss the natural progression from HTTP to WebSockets. It should cover topics such as the Upgrade header, the client/server handshake, transfer of data, and connection persistance. All of these concepts and more are covered in the MDN documentation. Security should also be covered in this lesson

	import { createServer } from 'node:http';
	import { Client } from 'undici';

	const server = createServer(
	{ keepAlive: true, keepAliveTimeout: 20 * 1000 },
	(req, res) => {
	res.writeHead(200, {
	'Content-Type': 'text/plain',
	connection: 'keep-alive',
	'keep-alive': 'timeout=20',

	import { createServer } from 'node:http';
	import { Pool } from 'undici';

	// Create a simple HTTP server that is configured with a 15s keep-alive timeout
	// And includes the 'Keep-Alive' header in responses
	const server = createServer(
	{ joinDuplicateHeaders: true, keepAlive: true, keepAliveTimeout: 15 * 1000 },
	(req, res) => {
	res.writeHead(200, {
	'Content-Type': 'text/plain',

	import { setInterval } from 'node:timers/promises';
	import assert from 'node:assert/strict';
	/**
	* A simple time-based polling function with a default timeout of 100ms.
	*
	* Some of the tests in this file require waiting for the file watcher to detect changes.
	* Files systems are not precise, and this is the best way to test file watcher behavior.
	*
	* If a test is flaky because of this mechanism, first consider what might be causing the file system to be slow (i.e. blocking I/O).
	* 100ms is quite short so for large operations (such as a large file write), it may be necessary to provide a longer timeout.

	const { Machine, interpret, send, sendParent } = require("xstate");
	const https = require('https');

	const CONNECTION_MONITOR_IPC_CHANNEL = 'connection-monitor'
	const PING_IPC_CHANNEL = 'ping'

	const CONNECTION_MONITOR_EVENTS = {
	TOGGLE_PING: 'toggle ping',
	CONNECT: 'connect',
	DISCONNECT: 'disconnect'


	// Available variables:
	// - Machine
	// - interpret
	// - assign
	// - send
	// - sendParent
	// - spawn
	// - raise
	// - actions

	Benchmark results for Headers class
	Tested modules: undici-fetch, node-fetch, ./implementations/mapHeaders.js

	Benchmark Suite results for operation: append
	┌─────────┬───────────────────────────────────┬───────────────────────┬────────────────────────────────────┐
	│ (index) │ Module │ Total Time │ Result │
	├─────────┼───────────────────────────────────┼───────────────────────┼────────────────────────────────────┤
	│ 0 │ 'undici-fetch' │ '552168ns (0.552ms)' │ null │
	│ 1 │ 'node-fetch' │ '1095718ns (1.096ms)' │ '98.439% slower than undici-fetch' │
	│ 2 │ './implementations/mapHeaders.js' │ '624987ns (0.625ms)' │ '13.188% slower than undici-fetch' │

	type ConnectionContext = {
	state: 'disconnected'
	methods: {
	connect: () => Promise<void>
	}
	} \| {
	state: 'connected',
	data: {
	endpoint: string
	},

	import { deepStrictEqual } from 'assert/strict';
	import { EventEmitter } from 'events';

	class StopLight extends EventEmitter {
	static _data = new Map([
	[ 'GO', { color: 'green' } ],
	[ 'STOP', { color: 'red' } ],
	[ 'SLOW', { color: 'yellow' } ]
	])