Step 3 / Select topic Node.js Easy

What this bank covers

• process.nextTick runs before timers
• Microtasks run before timer callbacks
• setTimeout returns a Timeout object in Node
• clearTimeout cancels a pending timer
• setInterval repeats until cleared
• Extra setTimeout arguments are passed to the callback
• nextTick queue beats the check phase
• A 0 ms timer still waits for the call stack to clear
• Timers fire in order of expiry, not registration
• process.nextTick vs setImmediate ordering
• Buffer.byteLength vs String.length
• Converting a Buffer to a hex string
• Base64 encoding a Buffer
• Indexing a Buffer yields a byte number
• latin1 encoding uses one byte per character
• Buffer.concat with an explicit totalLength
• Resolving a relative URL against a base
• URLSearchParams.get with repeated keys
• URL host vs hostname
• Error cause option
• unhandledRejection hook
• try/catch does not wrap async callbacks
• Rejections skip then handlers
• Environment values are strings
• Reading an unset environment variable
• Strict comparison against an env value
• process.pid
• process.version format
• Assigning undefined to process.env
• Deleting a process.env key
• process.argv contents
• Promise.all keeps input order
• Promise.race settles with the first result
• allSettled reports every outcome
• try/catch around await
• Microtasks drain before the check phase
• catch returning a value resumes the chain
• await always yields to a microtask
• once() listeners fire a single time
• The return value of emit()
• listenerCount counts one event name
• Listeners run in registration order
• prependListener puts a listener first
• removeListener needs the same function reference
• emit() calls listeners synchronously
• The default max listeners limit
• events.once() resolves with the emit arguments
• removeAllListeners with an event name
• Async iteration over a readable stream
• Return value of readable.pipe()
• Counting calls to a writable's _write
• Transform streams rewrite every chunk
• pipe() does not forward errors
• PassThrough forwards bytes unchanged
• Object mode preserves JavaScript values
• pipeline rejects on a stream error
• setEncoding on a readable stream
• PassThrough collects every written chunk
• buf.write returns bytes actually written
• subarray shares memory with the original buffer
• appendFileSync adds to the end of a file
• readFileSync without an encoding returns a Buffer
• stat().size reports the byte length of the file
• fs/promises readFile with an encoding resolves to a string
• mkdirSync with recursive: true is idempotent
• readdirSync returns names, not paths
• renameSync moves a file rather than copying it
• Missing files give an ENOENT error to the callback
• Stats.isFile() and Stats.isDirectory()
• appendFileSync creates the file when needed
• path.join normalizes segments
• path.extname takes only the last dot
• path.basename with a suffix argument
• path.resolve restarts at absolute segments
• require returns the cached exports object
• Reassigning exports does not change the export
• exports starts as an alias of module.exports
• A module body runs only once
• Assigning module.exports replaces earlier properties
• require parses .json files
• __filename inside a required module
• Circular require returns partial exports
• module.exports can be any value
• The cache is keyed by resolved filename
• AggregateError from Promise.any
• System error codes in fs callbacks
• try/catch does not cover async callbacks
• name on Error subclasses
• Unhandled 'error' events throw synchronously
• events.once resolves with an array of emitted arguments
• timers/promises setTimeout resolves with its value argument
• process.env key case sensitivity
• process.nextTick extra arguments