al-mighty/Drop-Nodejs14

Drop Node.js 14 support

Drop Node.js 14 support in your projects

• Now: April 2023, we have Node.js 18.16.0 LTS, 16.20.0 (maintenance) and 20.0.0 (latest)
• Going to drop Node.js 14 support in all HowProgrammingWorks and Node.js courses, Metarhia codebase
• Now we can rely on Node.js 16.20.0 capabilities
• See release schedule: https://github.com/nodejs/release#release-schedule

Refactoring checklist as of April 2023

• Due to the move from npm 6 to npm 8, convert package_lock.json to lockfileVersion 2
• Now we can use true #privateField syntax instead of _pseudoPrivateField or closures for "Information Hiding" principle
• Change deprecated cluster.isMaster to cluster.isPrimary, change cluster.setupMaster to cluster.setupPrimary
• Check all require calls to use node: prefix for all internal node.js modules, for example: node:fs
• Use crypto.randomUUID() to generate UUID instead of manual generation or third-party modules
• Stop using fs.exists; use fs.stat or fs.access instead
• Stop using fs.rmdir(path, { recursive: true }); use fs.rm(path, { recursive: true }) instead, see docs: https://nodejs.org/api/fs.html#fsrmpath-options-callback
• Check stream.destroyed instead of the .aborted property, and listen for close event instead of abort and aborted events for ClientRequest, ServerResponse, and IncomingMessage
• Stop using deprecated Server.connections; use Server.getConnections() instead, see docs: https://nodejs.org/api/net.html#servergetconnectionscallback
• Do not use default index.js as of Node.js 16.0.0; the main entry point should be explicitly defined
• Stop using emitter.listeners; use events.getEventListeners(emitter, eventName) instead, see docs: https://nodejs.org/api/events.html#eventsgeteventlistenersemitterortarget-eventname
• Now response (http.ServerResponse) has a reference to request instance (http.IncomingMessage): response.req
• Stop using node:url API; use JavaScript URL class instead
• Note that unhandled promise rejections are deprecated and will terminate the process with a non-zero exit code. Add a process.on('uncaughtException', (reason, origin) => {}) handler to prevent process termination
• Stop using deprecated process.on('multipleResolves', handler)
• Stop using deprecated process.config
• Check for deprecated Thenable support in streams
• Ensure only integer values are used for process.exit(code) and process.exitCode
• The well-known MODP groups modp1, modp2, and modp5 are deprecated due to their lack of security against practical attacks
• Use http.createServer({ noDelay, keepAlive, keepAliveInitialDelay }), no need in request.setNoDelay anymore
• New os.machine() returns one of machine types as a string: arm, arm64, aarch64, mips, mips64, ppc64, ppc64le, s390, s390x, i386, i686, x86_64

Explore new features

Available in all currently supported Node.js versions as of April 2023

• Use error.cause to chain errors like: new Error('message', { cause: error }), see docs: https://nodejs.org/api/errors.html#errorcause
• Use AbortController and AbortSignal in different async I/O APIs: exec/fork/spawn, events.once, readFile, stream.Writable/Readable, and so on
• Use AsyncLocalStorage, AsyncResource, see docs: https://nodejs.org/api/async_context.html
• Use multiple new promisified APIs: node:stream/promises, node:dns/promises, node:assert/strict
• Use node:timers/promises, for example await setTimeout(100)
• Use WeakReferences and FinalizationRegistry
• Use new Promise method any
• Use node:http improvements: server.maxRequestsPerSocket, response.strictContentLength, message.headersDistinct, message.trailersDistinct, outgoingMessage.appendHeader, http.setMaxIdleHTTPParsers, see docs: https://nodejs.org/api/http.html
• Discover multiple improvements in node:crypto
• Discover multiple improvements in Event API: Event and EventTarget classes: https://nodejs.org/api/events.html#eventtarget-and-event-api
• Discover class BlockList from node:net: https://nodejs.org/api/net.html#class-netblocklist
• Discover perf_hooks improvements like createHistogram, PerformanceMark, getEntries, PerformanceMeasure, PerformanceResourceTiming, multiple changes of PerformanceObserver and Histogram, new perf_hooks.performance: https://nodejs.org/api/perf_hooks.html
• Discover new Web Crypto API: https://nodejs.org/api/webcrypto.html
• Discover new node:worker_threads features getEnvironmentData and setEnvironmentData, new classes BroadcastChannel, EventTarget, and MessagePort, see docs: https://nodejs.org/api/worker_threads.html
• Discover Node.js native test runner from node:test: https://nodejs.org/api/test.html
• Take a look at the Diagnostics Channel API: https://nodejs.org/api/diagnostics_channel.html
• See node:net changes: Server event drop, socket.connect options: noDelay, keepAlive, and keepAliveInitialDelay, socket.localFamily, and socket.resetAndDestroy
• Discover Promise hooks API from node:v8m see docs: https://nodejs.org/api/v8.html#promise-hooks

Note that you can't freely use

• Following features are still experimental in at least one of supported node.js versions --watch, process.getActiveResourcesInfo, fs.cp, and fsPromises.cp, Readable methods map, filter, compose, iterator, forEach and so on
• ESM and CJS loaders API is currently being redesigned and will still change
• Startup Snapshot API and Web Streams API are still experimental, see docs: https://nodejs.org/api/v8.html#startup-snapshot-api