Referencia de la API node:util

Los auxiliares habituales disponibles en node:util incluyen:

format, formatWithOptions, inspect y stripVTControlCharacters;
promisify, callbackify, inherits, deprecate y debuglog;
isDeepStrictEqual, parseArgs, parseEnv y styleText;
getSystemErrorName, getSystemErrorMessage y getSystemErrorMap;
getCallSites;
los constructores globales TextEncoder y TextDecoder.

toUSVString() y el auxiliar heredado log() están presentes, pero lanzan un error de implementación.

Ejemplos

const util = require("node:util");

util.inspect({ a: [1, 2] }); // "{ a: [ 1, 2 ] }"
util.format("%s:%d", "port", 8080); // "port:8080"
util.isDeepStrictEqual({ a: 1 }, { a: 1 }); // true

inspect() gestiona los contenedores habituales, arrays tipados, buffers, funciones, referencias circulares, promesas y util.inspect.custom. Están disponibles opciones como depth, breakLength, compact y maxArrayLength.

promisify() respeta util.promisify.custom.

util.types

La familia de predicados cubre arrays y vistas habituales, fechas, mapas, conjuntos, errores, promesas, proxies, expresiones regulares, colecciones débiles, primitivas envueltas, tipos de función, iteradores y especializaciones de arrays tipados. No todos los predicados de Node están presentes; compruebe la existencia de predicados más recientes como isCryptoKey antes de llamarlos.

Véase también

API de util de Node.js

Reference

Status: Partial · 9 of 18 suite tests pass (50.0%) · since 1.1.0

Exports

Export	Kind	Status	Notes
`format()`	function	Full	Formats a string using printf-style substitution patterns (%s, %d, %o, etc.)
`formatWithOptions()`	function	Full	Like format(), but accepts an explicit util.inspect options object for the first argument
`inspect()`	function	Full	Returns a string representation of an object for debugging
`promisify()`	function	Full	Wraps a callback-based function so it returns a Promise
`inherits()`	function	Full	Sets up prototype inheritance between a constructor and a superclass
`isDeepStrictEqual()`	function	Full	Returns true if two values are deeply equal using the strict equality algorithm
`deprecate()`	function	Full	Wraps a function to emit a deprecation warning when called
`debuglog()`	function	Full	Returns a logging function that writes to stderr only if the NODE_DEBUG env variable includes section
`callbackify()`	function	Full	Wraps an async function (or a function that returns a Promise) so it follows the error-first callback…
`getSystemErrorName()`	function	Full	Returns the string name for a numeric error code (the errno value)
`getSystemErrorMessage()`	function	Full	Returns the string message for a numeric error code (the errno value)
`getSystemErrorMap()`	function	Full	Returns a Map of all system error codes to [name, message] pairs
`toUSVString()`	function	Full	Returns a string after replacing any lone surrogates with the Unicode replacement character U+FFFD
`stripVTControlCharacters()`	function	Full	Removes ANSI escape codes (including color and cursor movement) from a string
`styleText()`	function	Full	Formats text with ANSI styling for terminal output
`getCallSites()`	function	Full	Returns an array of call site objects representing the current call stack
`parseEnv()`	function	Full	Parses a .env file content string into a key-value object
`log()`	function	Full	Writes a formatted timestamp + message to stdout (similar to console.log but with a timestamp)
`types`	property	Full	Object with type-checking predicates (e.g. util.types.isDate, util.types.isMap)
`TextEncoder`	property	Full	The WHATWG TextEncoder class
`TextDecoder`	property	Full	The WHATWG TextDecoder class

Not implemented

convertProcessSignalToExitCode, debug, diff, isArray, setTraceSigInt, transferableAbortController, transferableAbortSignal.

Tests: node-api node:util: 9 pass, 8 fail, 1 error, 12 skipped. Failing: test-util-callbackify.js, test-util-format.js, test-util-getcallsites-preparestacktrace.js, test-util-getcallsites-sourcemap.js, test-util-inspect-getters-accessing-this.js, test-util-inspect-long-running.js, test-util-inspect-namespace.js, test-util-inspect-regexp.js, and 1 more.