Step 3 / Select topic Node.js Medium

What this bank covers

• What setTimeout returns in Node
• Extra arguments passed to a timer callback
• unref'd timers and process lifetime
• setTimeout returns a Timeout object in Node
• unref removes a timer's hold on the event loop
• Extra setTimeout arguments are forwarded to the callback
• UTF-8 byte length vs character count
• Base64 encoding of a 4-byte buffer
• Lenient hex decoding
• latin1 encoding is not UTF-8
• byteLength depends on the encoding
• Partial writes never split a UTF-8 character
• Decoding a truncated UTF-8 sequence
• Buffers compare by bytes, not by source encoding
• Buffer.from(arrayBuffer) creates a view, not a copy
• The 'ascii' decoder masks the high bit
• Resolving a relative URL against a base
• get versus getAll on URLSearchParams
• URL origin excludes credentials
• Root-relative references ignore the base directory
• URLSearchParams uses form encoding for spaces
• Default ports are dropped from a URL
• The URL parser removes dot segments from the path
• AggregateError from Promise.any
• uncaughtException keeps the loop alive
• Custom error subclasses and err.name
• unhandledRejection timing
• process.env stores only strings
• Assigning null to an environment variable
• delete removes a key from process.env
• The first element of process.argv
• The exit event handler is synchronous only
• process.version vs process.versions.node
• process.hrtime.bigint returns a BigInt
• process.env is live, a spread is a snapshot
• Assigning undefined to an environment variable
• process.env coerces values to strings
• for await over an array of promises
• Promise.allSettled result statuses
• Async function body before the first await
• Async functions reject instead of throwing
• Promise.race settles with the first result
• setImmediate vs setTimeout inside an I/O callback
• What setTimeout returns in Node.js
• setTimeout return value and extra arguments
• prependListener puts a listener at the front
• emit iterates over a snapshot of the listeners
• Unhandled 'error' events are thrown
• eventNames() only lists events that still have listeners
• once fires for a single emit and receives spread arguments
• Return value of emitter.emit
• once() fires at most one time
• listeners() vs rawListeners() for once handlers
• The newListener event fires before registration
• Readable.from defaults to object mode
• Transform callbacks push one chunk each
• write() return value and backpressure
• pipeline rejects and cleans up
• 'end' requires the data to be consumed
• setEncoding decodes chunks to strings
• 'finish' fires before 'close'
• highWaterMark is advisory, flowing starts as null
• The flush hook appends a trailing chunk
• writableEnded versus writableFinished
• readFileSync without an encoding
• Return value of recursive mkdirSync
• Error shape for a missing file
• The 'wx' exclusive write flag
• fs.writeSync with a position
• fs.truncateSync length argument
• renameSync over an existing destination
• readdirSync entries
• What fs/promises writeFile resolves to
• appendFileSync on a missing file
• path.join normalizes but keeps the trailing separator
• URL.host drops the default port for the scheme
• path.posix.join normalizes and clamps at root
• exports vs module.exports
• Module bodies run once
• Cached exports are shared state
• Invalidating require.cache
• Circular requires see partial exports
• The node: prefix for builtins
• The CommonJS module wrapper
• require.resolve does not load
• Failed loads are not cached
• Directory resolution and package.json main
• Node AssertionError fields
• events.errorMonitor does not consume 'error'
• stream/promises pipeline error propagation
• Errors from the WHATWG URL parser in Node
• Callback-style fs errors bypass try/catch
• util.promisify keeps only the first success value
• events.once resolves with an array of emitted arguments
• AsyncLocalStorage propagates across async boundaries
• Array.prototype.forEach does not await async callbacks
• nextTick drains between immediate callbacks