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1/**
2 * The `util` module supports the needs of Node.js internal APIs. Many of the
3 * utilities are useful for application and module developers as well. To access
4 * it:
5 *
6 * ```js
7 * const util = require('util');
8 * ```
9 * @see [source](https://github.com/nodejs/node/blob/v16.4.2/lib/util.js)
10 */
11declare module 'util' {
12 import * as types from 'node:util/types';
13 export interface InspectOptions {
14 /**
15 * If set to `true`, getters are going to be
16 * inspected as well. If set to `'get'` only getters without setter are going
17 * to be inspected. If set to `'set'` only getters having a corresponding
18 * setter are going to be inspected. This might cause side effects depending on
19 * the getter function.
20 * @default `false`
21 */
22 getters?: 'get' | 'set' | boolean | undefined;
23 showHidden?: boolean | undefined;
24 /**
25 * @default 2
26 */
27 depth?: number | null | undefined;
28 colors?: boolean | undefined;
29 customInspect?: boolean | undefined;
30 showProxy?: boolean | undefined;
31 maxArrayLength?: number | null | undefined;
32 /**
33 * Specifies the maximum number of characters to
34 * include when formatting. Set to `null` or `Infinity` to show all elements.
35 * Set to `0` or negative to show no characters.
36 * @default 10000
37 */
38 maxStringLength?: number | null | undefined;
39 breakLength?: number | undefined;
40 /**
41 * Setting this to `false` causes each object key
42 * to be displayed on a new line. It will also add new lines to text that is
43 * longer than `breakLength`. If set to a number, the most `n` inner elements
44 * are united on a single line as long as all properties fit into
45 * `breakLength`. Short array elements are also grouped together. Note that no
46 * text will be reduced below 16 characters, no matter the `breakLength` size.
47 * For more information, see the example below.
48 * @default `true`
49 */
50 compact?: boolean | number | undefined;
51 sorted?: boolean | ((a: string, b: string) => number) | undefined;
52 }
53 export type Style = 'special' | 'number' | 'bigint' | 'boolean' | 'undefined' | 'null' | 'string' | 'symbol' | 'date' | 'regexp' | 'module';
54 export type CustomInspectFunction = (depth: number, options: InspectOptionsStylized) => string;
55 export interface InspectOptionsStylized extends InspectOptions {
56 stylize(text: string, styleType: Style): string;
57 }
58 /**
59 * The `util.format()` method returns a formatted string using the first argument
60 * as a `printf`\-like format string which can contain zero or more format
61 * specifiers. Each specifier is replaced with the converted value from the
62 * corresponding argument. Supported specifiers are:
63 *
64 * If a specifier does not have a corresponding argument, it is not replaced:
65 *
66 * ```js
67 * util.format('%s:%s', 'foo');
68 * // Returns: 'foo:%s'
69 * ```
70 *
71 * Values that are not part of the format string are formatted using`util.inspect()` if their type is not `string`.
72 *
73 * If there are more arguments passed to the `util.format()` method than the
74 * number of specifiers, the extra arguments are concatenated to the returned
75 * string, separated by spaces:
76 *
77 * ```js
78 * util.format('%s:%s', 'foo', 'bar', 'baz');
79 * // Returns: 'foo:bar baz'
80 * ```
81 *
82 * If the first argument does not contain a valid format specifier, `util.format()`returns a string that is the concatenation of all arguments separated by spaces:
83 *
84 * ```js
85 * util.format(1, 2, 3);
86 * // Returns: '1 2 3'
87 * ```
88 *
89 * If only one argument is passed to `util.format()`, it is returned as it is
90 * without any formatting:
91 *
92 * ```js
93 * util.format('%% %s');
94 * // Returns: '%% %s'
95 * ```
96 *
97 * `util.format()` is a synchronous method that is intended as a debugging tool.
98 * Some input values can have a significant performance overhead that can block the
99 * event loop. Use this function with care and never in a hot code path.
100 * @since v0.5.3
101 * @param format A `printf`-like format string.
102 */
103 export function format(format?: any, ...param: any[]): string;
104 /**
105 * This function is identical to {@link format}, except in that it takes
106 * an `inspectOptions` argument which specifies options that are passed along to {@link inspect}.
107 *
108 * ```js
109 * util.formatWithOptions({ colors: true }, 'See object %O', { foo: 42 });
110 * // Returns 'See object { foo: 42 }', where `42` is colored as a number
111 * // when printed to a terminal.
112 * ```
113 * @since v10.0.0
114 */
115 export function formatWithOptions(inspectOptions: InspectOptions, format?: any, ...param: any[]): string;
116 /**
117 * Returns a Map of all system error codes available from the Node.js API.
118 * The mapping between error codes and error names is platform-dependent.
119 * See `Common System Errors` for the names of common errors.
120 *
121 * ```js
122 * fs.access('file/that/does/not/exist', (err) => {
123 * const errorMap = util.getSystemErrorMap();
124 * const name = errorMap.get(err.errno);
125 * console.error(name); // ENOENT
126 * });
127 * ```
128 * @since v16.0.0
129 */
130 export function getSystemErrorMap(): Map<number, [string, string]>;
131 /**
132 * The `util.log()` method prints the given `string` to `stdout` with an included
133 * timestamp.
134 *
135 * ```js
136 * const util = require('util');
137 *
138 * util.log('Timestamped message.');
139 * ```
140 * @since v0.3.0
141 * @deprecated Since v6.0.0 - Use a third party module instead.
142 */
143 export function log(string: string): void;
144 /**
145 * The `util.inspect()` method returns a string representation of `object` that is
146 * intended for debugging. The output of `util.inspect` may change at any time
147 * and should not be depended upon programmatically. Additional `options` may be
148 * passed that alter the result.`util.inspect()` will use the constructor's name and/or `@@toStringTag` to make
149 * an identifiable tag for an inspected value.
150 *
151 * ```js
152 * class Foo {
153 * get [Symbol.toStringTag]() {
154 * return 'bar';
155 * }
156 * }
157 *
158 * class Bar {}
159 *
160 * const baz = Object.create(null, { [Symbol.toStringTag]: { value: 'foo' } });
161 *
162 * util.inspect(new Foo()); // 'Foo [bar] {}'
163 * util.inspect(new Bar()); // 'Bar {}'
164 * util.inspect(baz); // '[foo] {}'
165 * ```
166 *
167 * Circular references point to their anchor by using a reference index:
168 *
169 * ```js
170 * const { inspect } = require('util');
171 *
172 * const obj = {};
173 * obj.a = [obj];
174 * obj.b = {};
175 * obj.b.inner = obj.b;
176 * obj.b.obj = obj;
177 *
178 * console.log(inspect(obj));
179 * // <ref *1> {
180 * // a: [ [Circular *1] ],
181 * // b: <ref *2> { inner: [Circular *2], obj: [Circular *1] }
182 * // }
183 * ```
184 *
185 * The following example inspects all properties of the `util` object:
186 *
187 * ```js
188 * const util = require('util');
189 *
190 * console.log(util.inspect(util, { showHidden: true, depth: null }));
191 * ```
192 *
193 * The following example highlights the effect of the `compact` option:
194 *
195 * ```js
196 * const util = require('util');
197 *
198 * const o = {
199 * a: [1, 2, [[
200 * 'Lorem ipsum dolor sit amet,\nconsectetur adipiscing elit, sed do ' +
201 * 'eiusmod \ntempor incididunt ut labore et dolore magna aliqua.',
202 * 'test',
203 * 'foo']], 4],
204 * b: new Map([['za', 1], ['zb', 'test']])
205 * };
206 * console.log(util.inspect(o, { compact: true, depth: 5, breakLength: 80 }));
207 *
208 * // { a:
209 * // [ 1,
210 * // 2,
211 * // [ [ 'Lorem ipsum dolor sit amet,\nconsectetur [...]', // A long line
212 * // 'test',
213 * // 'foo' ] ],
214 * // 4 ],
215 * // b: Map(2) { 'za' => 1, 'zb' => 'test' } }
216 *
217 * // Setting `compact` to false or an integer creates more reader friendly output.
218 * console.log(util.inspect(o, { compact: false, depth: 5, breakLength: 80 }));
219 *
220 * // {
221 * // a: [
222 * // 1,
223 * // 2,
224 * // [
225 * // [
226 * // 'Lorem ipsum dolor sit amet,\n' +
227 * // 'consectetur adipiscing elit, sed do eiusmod \n' +
228 * // 'tempor incididunt ut labore et dolore magna aliqua.',
229 * // 'test',
230 * // 'foo'
231 * // ]
232 * // ],
233 * // 4
234 * // ],
235 * // b: Map(2) {
236 * // 'za' => 1,
237 * // 'zb' => 'test'
238 * // }
239 * // }
240 *
241 * // Setting `breakLength` to e.g. 150 will print the "Lorem ipsum" text in a
242 * // single line.
243 * ```
244 *
245 * The `showHidden` option allows [`WeakMap`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap) and
246 * [`WeakSet`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet) entries to be
247 * inspected. If there are more entries than `maxArrayLength`, there is no
248 * guarantee which entries are displayed. That means retrieving the same[`WeakSet`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet) entries twice may
249 * result in different output. Furthermore, entries
250 * with no remaining strong references may be garbage collected at any time.
251 *
252 * ```js
253 * const { inspect } = require('util');
254 *
255 * const obj = { a: 1 };
256 * const obj2 = { b: 2 };
257 * const weakSet = new WeakSet([obj, obj2]);
258 *
259 * console.log(inspect(weakSet, { showHidden: true }));
260 * // WeakSet { { a: 1 }, { b: 2 } }
261 * ```
262 *
263 * The `sorted` option ensures that an object's property insertion order does not
264 * impact the result of `util.inspect()`.
265 *
266 * ```js
267 * const { inspect } = require('util');
268 * const assert = require('assert');
269 *
270 * const o1 = {
271 * b: [2, 3, 1],
272 * a: '`a` comes before `b`',
273 * c: new Set([2, 3, 1])
274 * };
275 * console.log(inspect(o1, { sorted: true }));
276 * // { a: '`a` comes before `b`', b: [ 2, 3, 1 ], c: Set(3) { 1, 2, 3 } }
277 * console.log(inspect(o1, { sorted: (a, b) => b.localeCompare(a) }));
278 * // { c: Set(3) { 3, 2, 1 }, b: [ 2, 3, 1 ], a: '`a` comes before `b`' }
279 *
280 * const o2 = {
281 * c: new Set([2, 1, 3]),
282 * a: '`a` comes before `b`',
283 * b: [2, 3, 1]
284 * };
285 * assert.strict.equal(
286 * inspect(o1, { sorted: true }),
287 * inspect(o2, { sorted: true })
288 * );
289 * ```
290 *
291 * `util.inspect()` is a synchronous method intended for debugging. Its maximum
292 * output length is approximately 128 MB. Inputs that result in longer output will
293 * be truncated.
294 * @since v0.3.0
295 * @param object Any JavaScript primitive or `Object`.
296 * @return The representation of `object`.
297 */
298 export function inspect(object: any, showHidden?: boolean, depth?: number | null, color?: boolean): string;
299 export function inspect(object: any, options: InspectOptions): string;
300 export namespace inspect {
301 let colors: NodeJS.Dict<[number, number]>;
302 let styles: {
303 [K in Style]: string;
304 };
305 let defaultOptions: InspectOptions;
306 /**
307 * Allows changing inspect settings from the repl.
308 */
309 let replDefaults: InspectOptions;
310 const custom: unique symbol;
311 }
312 /**
313 * Alias for [`Array.isArray()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray).
314 *
315 * Returns `true` if the given `object` is an `Array`. Otherwise, returns `false`.
316 *
317 * ```js
318 * const util = require('util');
319 *
320 * util.isArray([]);
321 * // Returns: true
322 * util.isArray(new Array());
323 * // Returns: true
324 * util.isArray({});
325 * // Returns: false
326 * ```
327 * @since v0.6.0
328 * @deprecated Since v4.0.0 - Use `isArray` instead.
329 */
330 export function isArray(object: unknown): object is unknown[];
331 /**
332 * Returns `true` if the given `object` is a `RegExp`. Otherwise, returns `false`.
333 *
334 * ```js
335 * const util = require('util');
336 *
337 * util.isRegExp(/some regexp/);
338 * // Returns: true
339 * util.isRegExp(new RegExp('another regexp'));
340 * // Returns: true
341 * util.isRegExp({});
342 * // Returns: false
343 * ```
344 * @since v0.6.0
345 * @deprecated Since v4.0.0 - Deprecated
346 */
347 export function isRegExp(object: unknown): object is RegExp;
348 /**
349 * Returns `true` if the given `object` is a `Date`. Otherwise, returns `false`.
350 *
351 * ```js
352 * const util = require('util');
353 *
354 * util.isDate(new Date());
355 * // Returns: true
356 * util.isDate(Date());
357 * // false (without 'new' returns a String)
358 * util.isDate({});
359 * // Returns: false
360 * ```
361 * @since v0.6.0
362 * @deprecated Since v4.0.0 - Use {@link types.isDate} instead.
363 */
364 export function isDate(object: unknown): object is Date;
365 /**
366 * Returns `true` if the given `object` is an `Error`. Otherwise, returns`false`.
367 *
368 * ```js
369 * const util = require('util');
370 *
371 * util.isError(new Error());
372 * // Returns: true
373 * util.isError(new TypeError());
374 * // Returns: true
375 * util.isError({ name: 'Error', message: 'an error occurred' });
376 * // Returns: false
377 * ```
378 *
379 * This method relies on `Object.prototype.toString()` behavior. It is
380 * possible to obtain an incorrect result when the `object` argument manipulates`@@toStringTag`.
381 *
382 * ```js
383 * const util = require('util');
384 * const obj = { name: 'Error', message: 'an error occurred' };
385 *
386 * util.isError(obj);
387 * // Returns: false
388 * obj[Symbol.toStringTag] = 'Error';
389 * util.isError(obj);
390 * // Returns: true
391 * ```
392 * @since v0.6.0
393 * @deprecated Since v4.0.0 - Use {@link types.isNativeError} instead.
394 */
395 export function isError(object: unknown): object is Error;
396 /**
397 * Usage of `util.inherits()` is discouraged. Please use the ES6 `class` and`extends` keywords to get language level inheritance support. Also note
398 * that the two styles are [semantically incompatible](https://github.com/nodejs/node/issues/4179).
399 *
400 * Inherit the prototype methods from one [constructor](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/constructor) into another. The
401 * prototype of `constructor` will be set to a new object created from`superConstructor`.
402 *
403 * This mainly adds some input validation on top of`Object.setPrototypeOf(constructor.prototype, superConstructor.prototype)`.
404 * As an additional convenience, `superConstructor` will be accessible
405 * through the `constructor.super_` property.
406 *
407 * ```js
408 * const util = require('util');
409 * const EventEmitter = require('events');
410 *
411 * function MyStream() {
412 * EventEmitter.call(this);
413 * }
414 *
415 * util.inherits(MyStream, EventEmitter);
416 *
417 * MyStream.prototype.write = function(data) {
418 * this.emit('data', data);
419 * };
420 *
421 * const stream = new MyStream();
422 *
423 * console.log(stream instanceof EventEmitter); // true
424 * console.log(MyStream.super_ === EventEmitter); // true
425 *
426 * stream.on('data', (data) => {
427 * console.log(`Received data: "${data}"`);
428 * });
429 * stream.write('It works!'); // Received data: "It works!"
430 * ```
431 *
432 * ES6 example using `class` and `extends`:
433 *
434 * ```js
435 * const EventEmitter = require('events');
436 *
437 * class MyStream extends EventEmitter {
438 * write(data) {
439 * this.emit('data', data);
440 * }
441 * }
442 *
443 * const stream = new MyStream();
444 *
445 * stream.on('data', (data) => {
446 * console.log(`Received data: "${data}"`);
447 * });
448 * stream.write('With ES6');
449 * ```
450 * @since v0.3.0
451 * @deprecated Legacy: Use ES2015 class syntax and `extends` keyword instead.
452 */
453 export function inherits(constructor: unknown, superConstructor: unknown): void;
454 export type DebugLoggerFunction = (msg: string, ...param: unknown[]) => void;
455 export interface DebugLogger extends DebugLoggerFunction {
456 enabled: boolean;
457 }
458 /**
459 * The `util.debuglog()` method is used to create a function that conditionally
460 * writes debug messages to `stderr` based on the existence of the `NODE_DEBUG`environment variable. If the `section` name appears within the value of that
461 * environment variable, then the returned function operates similar to `console.error()`. If not, then the returned function is a no-op.
462 *
463 * ```js
464 * const util = require('util');
465 * const debuglog = util.debuglog('foo');
466 *
467 * debuglog('hello from foo [%d]', 123);
468 * ```
469 *
470 * If this program is run with `NODE_DEBUG=foo` in the environment, then
471 * it will output something like:
472 *
473 * ```console
474 * FOO 3245: hello from foo [123]
475 * ```
476 *
477 * where `3245` is the process id. If it is not run with that
478 * environment variable set, then it will not print anything.
479 *
480 * The `section` supports wildcard also:
481 *
482 * ```js
483 * const util = require('util');
484 * const debuglog = util.debuglog('foo-bar');
485 *
486 * debuglog('hi there, it\'s foo-bar [%d]', 2333);
487 * ```
488 *
489 * if it is run with `NODE_DEBUG=foo*` in the environment, then it will output
490 * something like:
491 *
492 * ```console
493 * FOO-BAR 3257: hi there, it's foo-bar [2333]
494 * ```
495 *
496 * Multiple comma-separated `section` names may be specified in the `NODE_DEBUG`environment variable: `NODE_DEBUG=fs,net,tls`.
497 *
498 * The optional `callback` argument can be used to replace the logging function
499 * with a different function that doesn't have any initialization or
500 * unnecessary wrapping.
501 *
502 * ```js
503 * const util = require('util');
504 * let debuglog = util.debuglog('internals', (debug) => {
505 * // Replace with a logging function that optimizes out
506 * // testing if the section is enabled
507 * debuglog = debug;
508 * });
509 * ```
510 * @since v0.11.3
511 * @param section A string identifying the portion of the application for which the `debuglog` function is being created.
512 * @param callback A callback invoked the first time the logging function is called with a function argument that is a more optimized logging function.
513 * @return The logging function
514 */
515 export function debuglog(section: string, callback?: (fn: DebugLoggerFunction) => void): DebugLogger;
516 /**
517 * Returns `true` if the given `object` is a `Boolean`. Otherwise, returns `false`.
518 *
519 * ```js
520 * const util = require('util');
521 *
522 * util.isBoolean(1);
523 * // Returns: false
524 * util.isBoolean(0);
525 * // Returns: false
526 * util.isBoolean(false);
527 * // Returns: true
528 * ```
529 * @since v0.11.5
530 * @deprecated Since v4.0.0 - Use `typeof value === 'boolean'` instead.
531 */
532 export function isBoolean(object: unknown): object is boolean;
533 /**
534 * Returns `true` if the given `object` is a `Buffer`. Otherwise, returns `false`.
535 *
536 * ```js
537 * const util = require('util');
538 *
539 * util.isBuffer({ length: 0 });
540 * // Returns: false
541 * util.isBuffer([]);
542 * // Returns: false
543 * util.isBuffer(Buffer.from('hello world'));
544 * // Returns: true
545 * ```
546 * @since v0.11.5
547 * @deprecated Since v4.0.0 - Use `isBuffer` instead.
548 */
549 export function isBuffer(object: unknown): object is Buffer;
550 /**
551 * Returns `true` if the given `object` is a `Function`. Otherwise, returns`false`.
552 *
553 * ```js
554 * const util = require('util');
555 *
556 * function Foo() {}
557 * const Bar = () => {};
558 *
559 * util.isFunction({});
560 * // Returns: false
561 * util.isFunction(Foo);
562 * // Returns: true
563 * util.isFunction(Bar);
564 * // Returns: true
565 * ```
566 * @since v0.11.5
567 * @deprecated Since v4.0.0 - Use `typeof value === 'function'` instead.
568 */
569 export function isFunction(object: unknown): boolean;
570 /**
571 * Returns `true` if the given `object` is strictly `null`. Otherwise, returns`false`.
572 *
573 * ```js
574 * const util = require('util');
575 *
576 * util.isNull(0);
577 * // Returns: false
578 * util.isNull(undefined);
579 * // Returns: false
580 * util.isNull(null);
581 * // Returns: true
582 * ```
583 * @since v0.11.5
584 * @deprecated Since v4.0.0 - Use `value === null` instead.
585 */
586 export function isNull(object: unknown): object is null;
587 /**
588 * Returns `true` if the given `object` is `null` or `undefined`. Otherwise,
589 * returns `false`.
590 *
591 * ```js
592 * const util = require('util');
593 *
594 * util.isNullOrUndefined(0);
595 * // Returns: false
596 * util.isNullOrUndefined(undefined);
597 * // Returns: true
598 * util.isNullOrUndefined(null);
599 * // Returns: true
600 * ```
601 * @since v0.11.5
602 * @deprecated Since v4.0.0 - Use `value === undefined || value === null` instead.
603 */
604 export function isNullOrUndefined(object: unknown): object is null | undefined;
605 /**
606 * Returns `true` if the given `object` is a `Number`. Otherwise, returns `false`.
607 *
608 * ```js
609 * const util = require('util');
610 *
611 * util.isNumber(false);
612 * // Returns: false
613 * util.isNumber(Infinity);
614 * // Returns: true
615 * util.isNumber(0);
616 * // Returns: true
617 * util.isNumber(NaN);
618 * // Returns: true
619 * ```
620 * @since v0.11.5
621 * @deprecated Since v4.0.0 - Use `typeof value === 'number'` instead.
622 */
623 export function isNumber(object: unknown): object is number;
624 /**
625 * Returns `true` if the given `object` is strictly an `Object`**and** not a`Function` (even though functions are objects in JavaScript).
626 * Otherwise, returns `false`.
627 *
628 * ```js
629 * const util = require('util');
630 *
631 * util.isObject(5);
632 * // Returns: false
633 * util.isObject(null);
634 * // Returns: false
635 * util.isObject({});
636 * // Returns: true
637 * util.isObject(() => {});
638 * // Returns: false
639 * ```
640 * @since v0.11.5
641 * @deprecated Since v4.0.0 - Deprecated: Use `value !== null && typeof value === 'object'` instead.
642 */
643 export function isObject(object: unknown): boolean;
644 /**
645 * Returns `true` if the given `object` is a primitive type. Otherwise, returns`false`.
646 *
647 * ```js
648 * const util = require('util');
649 *
650 * util.isPrimitive(5);
651 * // Returns: true
652 * util.isPrimitive('foo');
653 * // Returns: true
654 * util.isPrimitive(false);
655 * // Returns: true
656 * util.isPrimitive(null);
657 * // Returns: true
658 * util.isPrimitive(undefined);
659 * // Returns: true
660 * util.isPrimitive({});
661 * // Returns: false
662 * util.isPrimitive(() => {});
663 * // Returns: false
664 * util.isPrimitive(/^$/);
665 * // Returns: false
666 * util.isPrimitive(new Date());
667 * // Returns: false
668 * ```
669 * @since v0.11.5
670 * @deprecated Since v4.0.0 - Use `(typeof value !== 'object' && typeof value !== 'function') || value === null` instead.
671 */
672 export function isPrimitive(object: unknown): boolean;
673 /**
674 * Returns `true` if the given `object` is a `string`. Otherwise, returns `false`.
675 *
676 * ```js
677 * const util = require('util');
678 *
679 * util.isString('');
680 * // Returns: true
681 * util.isString('foo');
682 * // Returns: true
683 * util.isString(String('foo'));
684 * // Returns: true
685 * util.isString(5);
686 * // Returns: false
687 * ```
688 * @since v0.11.5
689 * @deprecated Since v4.0.0 - Use `typeof value === 'string'` instead.
690 */
691 export function isString(object: unknown): object is string;
692 /**
693 * Returns `true` if the given `object` is a `Symbol`. Otherwise, returns `false`.
694 *
695 * ```js
696 * const util = require('util');
697 *
698 * util.isSymbol(5);
699 * // Returns: false
700 * util.isSymbol('foo');
701 * // Returns: false
702 * util.isSymbol(Symbol('foo'));
703 * // Returns: true
704 * ```
705 * @since v0.11.5
706 * @deprecated Since v4.0.0 - Use `typeof value === 'symbol'` instead.
707 */
708 export function isSymbol(object: unknown): object is symbol;
709 /**
710 * Returns `true` if the given `object` is `undefined`. Otherwise, returns `false`.
711 *
712 * ```js
713 * const util = require('util');
714 *
715 * const foo = undefined;
716 * util.isUndefined(5);
717 * // Returns: false
718 * util.isUndefined(foo);
719 * // Returns: true
720 * util.isUndefined(null);
721 * // Returns: false
722 * ```
723 * @since v0.11.5
724 * @deprecated Since v4.0.0 - Use `value === undefined` instead.
725 */
726 export function isUndefined(object: unknown): object is undefined;
727 /**
728 * The `util.deprecate()` method wraps `fn` (which may be a function or class) in
729 * such a way that it is marked as deprecated.
730 *
731 * ```js
732 * const util = require('util');
733 *
734 * exports.obsoleteFunction = util.deprecate(() => {
735 * // Do something here.
736 * }, 'obsoleteFunction() is deprecated. Use newShinyFunction() instead.');
737 * ```
738 *
739 * When called, `util.deprecate()` will return a function that will emit a`DeprecationWarning` using the `'warning'` event. The warning will
740 * be emitted and printed to `stderr` the first time the returned function is
741 * called. After the warning is emitted, the wrapped function is called without
742 * emitting a warning.
743 *
744 * If the same optional `code` is supplied in multiple calls to `util.deprecate()`,
745 * the warning will be emitted only once for that `code`.
746 *
747 * ```js
748 * const util = require('util');
749 *
750 * const fn1 = util.deprecate(someFunction, someMessage, 'DEP0001');
751 * const fn2 = util.deprecate(someOtherFunction, someOtherMessage, 'DEP0001');
752 * fn1(); // Emits a deprecation warning with code DEP0001
753 * fn2(); // Does not emit a deprecation warning because it has the same code
754 * ```
755 *
756 * If either the `--no-deprecation` or `--no-warnings` command-line flags are
757 * used, or if the `process.noDeprecation` property is set to `true`_prior_ to
758 * the first deprecation warning, the `util.deprecate()` method does nothing.
759 *
760 * If the `--trace-deprecation` or `--trace-warnings` command-line flags are set,
761 * or the `process.traceDeprecation` property is set to `true`, a warning and a
762 * stack trace are printed to `stderr` the first time the deprecated function is
763 * called.
764 *
765 * If the `--throw-deprecation` command-line flag is set, or the`process.throwDeprecation` property is set to `true`, then an exception will be
766 * thrown when the deprecated function is called.
767 *
768 * The `--throw-deprecation` command-line flag and `process.throwDeprecation`property take precedence over `--trace-deprecation` and`process.traceDeprecation`.
769 * @since v0.8.0
770 * @param fn The function that is being deprecated.
771 * @param msg A warning message to display when the deprecated function is invoked.
772 * @param code A deprecation code. See the `list of deprecated APIs` for a list of codes.
773 * @return The deprecated function wrapped to emit a warning.
774 */
775 export function deprecate<T extends Function>(fn: T, msg: string, code?: string): T;
776 /**
777 * Returns `true` if there is deep strict equality between `val1` and `val2`.
778 * Otherwise, returns `false`.
779 *
780 * See `assert.deepStrictEqual()` for more information about deep strict
781 * equality.
782 * @since v9.0.0
783 */
784 export function isDeepStrictEqual(val1: unknown, val2: unknown): boolean;
785 /**
786 * Takes an `async` function (or a function that returns a `Promise`) and returns a
787 * function following the error-first callback style, i.e. taking
788 * an `(err, value) => ...` callback as the last argument. In the callback, the
789 * first argument will be the rejection reason (or `null` if the `Promise`resolved), and the second argument will be the resolved value.
790 *
791 * ```js
792 * const util = require('util');
793 *
794 * async function fn() {
795 * return 'hello world';
796 * }
797 * const callbackFunction = util.callbackify(fn);
798 *
799 * callbackFunction((err, ret) => {
800 * if (err) throw err;
801 * console.log(ret);
802 * });
803 * ```
804 *
805 * Will print:
806 *
807 * ```text
808 * hello world
809 * ```
810 *
811 * The callback is executed asynchronously, and will have a limited stack trace.
812 * If the callback throws, the process will emit an `'uncaughtException'` event, and if not handled will exit.
813 *
814 * Since `null` has a special meaning as the first argument to a callback, if a
815 * wrapped function rejects a `Promise` with a falsy value as a reason, the value
816 * is wrapped in an `Error` with the original value stored in a field named`reason`.
817 *
818 * ```js
819 * function fn() {
820 * return Promise.reject(null);
821 * }
822 * const callbackFunction = util.callbackify(fn);
823 *
824 * callbackFunction((err, ret) => {
825 * // When the Promise was rejected with `null` it is wrapped with an Error and
826 * // the original value is stored in `reason`.
827 * err &#x26;&#x26; err.hasOwnProperty('reason') &#x26;&#x26; err.reason === null; // true
828 * });
829 * ```
830 * @since v8.2.0
831 * @param original An `async` function
832 * @return a callback style function
833 */
834 export function callbackify(fn: () => Promise<void>): (callback: (err: NodeJS.ErrnoException) => void) => void;
835 export function callbackify<TResult>(fn: () => Promise<TResult>): (callback: (err: NodeJS.ErrnoException, result: TResult) => void) => void;
836 export function callbackify<T1>(fn: (arg1: T1) => Promise<void>): (arg1: T1, callback: (err: NodeJS.ErrnoException) => void) => void;
837 export function callbackify<T1, TResult>(fn: (arg1: T1) => Promise<TResult>): (arg1: T1, callback: (err: NodeJS.ErrnoException, result: TResult) => void) => void;
838 export function callbackify<T1, T2>(fn: (arg1: T1, arg2: T2) => Promise<void>): (arg1: T1, arg2: T2, callback: (err: NodeJS.ErrnoException) => void) => void;
839 export function callbackify<T1, T2, TResult>(fn: (arg1: T1, arg2: T2) => Promise<TResult>): (arg1: T1, arg2: T2, callback: (err: NodeJS.ErrnoException | null, result: TResult) => void) => void;
840 export function callbackify<T1, T2, T3>(fn: (arg1: T1, arg2: T2, arg3: T3) => Promise<void>): (arg1: T1, arg2: T2, arg3: T3, callback: (err: NodeJS.ErrnoException) => void) => void;
841 export function callbackify<T1, T2, T3, TResult>(
842 fn: (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>
843 ): (arg1: T1, arg2: T2, arg3: T3, callback: (err: NodeJS.ErrnoException | null, result: TResult) => void) => void;
844 export function callbackify<T1, T2, T3, T4>(
845 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>
846 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: NodeJS.ErrnoException) => void) => void;
847 export function callbackify<T1, T2, T3, T4, TResult>(
848 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>
849 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: NodeJS.ErrnoException | null, result: TResult) => void) => void;
850 export function callbackify<T1, T2, T3, T4, T5>(
851 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>
852 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: NodeJS.ErrnoException) => void) => void;
853 export function callbackify<T1, T2, T3, T4, T5, TResult>(
854 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>
855 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: NodeJS.ErrnoException | null, result: TResult) => void) => void;
856 export function callbackify<T1, T2, T3, T4, T5, T6>(
857 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6) => Promise<void>
858 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6, callback: (err: NodeJS.ErrnoException) => void) => void;
859 export function callbackify<T1, T2, T3, T4, T5, T6, TResult>(
860 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6) => Promise<TResult>
861 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6, callback: (err: NodeJS.ErrnoException | null, result: TResult) => void) => void;
862 export interface CustomPromisifyLegacy<TCustom extends Function> extends Function {
863 __promisify__: TCustom;
864 }
865 export interface CustomPromisifySymbol<TCustom extends Function> extends Function {
866 [promisify.custom]: TCustom;
867 }
868 export type CustomPromisify<TCustom extends Function> = CustomPromisifySymbol<TCustom> | CustomPromisifyLegacy<TCustom>;
869 /**
870 * Takes a function following the common error-first callback style, i.e. taking
871 * an `(err, value) => ...` callback as the last argument, and returns a version
872 * that returns promises.
873 *
874 * ```js
875 * const util = require('util');
876 * const fs = require('fs');
877 *
878 * const stat = util.promisify(fs.stat);
879 * stat('.').then((stats) => {
880 * // Do something with `stats`
881 * }).catch((error) => {
882 * // Handle the error.
883 * });
884 * ```
885 *
886 * Or, equivalently using `async function`s:
887 *
888 * ```js
889 * const util = require('util');
890 * const fs = require('fs');
891 *
892 * const stat = util.promisify(fs.stat);
893 *
894 * async function callStat() {
895 * const stats = await stat('.');
896 * console.log(`This directory is owned by ${stats.uid}`);
897 * }
898 * ```
899 *
900 * If there is an `original[util.promisify.custom]` property present, `promisify`will return its value, see `Custom promisified functions`.
901 *
902 * `promisify()` assumes that `original` is a function taking a callback as its
903 * final argument in all cases. If `original` is not a function, `promisify()`will throw an error. If `original` is a function but its last argument is not
904 * an error-first callback, it will still be passed an error-first
905 * callback as its last argument.
906 *
907 * Using `promisify()` on class methods or other methods that use `this` may not
908 * work as expected unless handled specially:
909 *
910 * ```js
911 * const util = require('util');
912 *
913 * class Foo {
914 * constructor() {
915 * this.a = 42;
916 * }
917 *
918 * bar(callback) {
919 * callback(null, this.a);
920 * }
921 * }
922 *
923 * const foo = new Foo();
924 *
925 * const naiveBar = util.promisify(foo.bar);
926 * // TypeError: Cannot read property 'a' of undefined
927 * // naiveBar().then(a => console.log(a));
928 *
929 * naiveBar.call(foo).then((a) => console.log(a)); // '42'
930 *
931 * const bindBar = naiveBar.bind(foo);
932 * bindBar().then((a) => console.log(a)); // '42'
933 * ```
934 * @since v8.0.0
935 */
936 export function promisify<TCustom extends Function>(fn: CustomPromisify<TCustom>): TCustom;
937 export function promisify<TResult>(fn: (callback: (err: any, result: TResult) => void) => void): () => Promise<TResult>;
938 export function promisify(fn: (callback: (err?: any) => void) => void): () => Promise<void>;
939 export function promisify<T1, TResult>(fn: (arg1: T1, callback: (err: any, result: TResult) => void) => void): (arg1: T1) => Promise<TResult>;
940 export function promisify<T1>(fn: (arg1: T1, callback: (err?: any) => void) => void): (arg1: T1) => Promise<void>;
941 export function promisify<T1, T2, TResult>(fn: (arg1: T1, arg2: T2, callback: (err: any, result: TResult) => void) => void): (arg1: T1, arg2: T2) => Promise<TResult>;
942 export function promisify<T1, T2>(fn: (arg1: T1, arg2: T2, callback: (err?: any) => void) => void): (arg1: T1, arg2: T2) => Promise<void>;
943 export function promisify<T1, T2, T3, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: any, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>;
944 export function promisify<T1, T2, T3>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err?: any) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<void>;
945 export function promisify<T1, T2, T3, T4, TResult>(
946 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: any, result: TResult) => void) => void
947 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>;
948 export function promisify<T1, T2, T3, T4>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err?: any) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>;
949 export function promisify<T1, T2, T3, T4, T5, TResult>(
950 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: any, result: TResult) => void) => void
951 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>;
952 export function promisify<T1, T2, T3, T4, T5>(
953 fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err?: any) => void) => void
954 ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>;
955 export function promisify(fn: Function): Function;
956 export namespace promisify {
957 const custom: unique symbol;
958 }
959 /**
960 * An implementation of the [WHATWG Encoding Standard](https://encoding.spec.whatwg.org/)`TextDecoder` API.
961 *
962 * ```js
963 * const decoder = new TextDecoder('shift_jis');
964 * let string = '';
965 * let buffer;
966 * while (buffer = getNextChunkSomehow()) {
967 * string += decoder.decode(buffer, { stream: true });
968 * }
969 * string += decoder.decode(); // end-of-stream
970 * ```
971 * @since v8.3.0
972 */
973 export class TextDecoder {
974 /**
975 * The encoding supported by the `TextDecoder` instance.
976 */
977 readonly encoding: string;
978 /**
979 * The value will be `true` if decoding errors result in a `TypeError` being
980 * thrown.
981 */
982 readonly fatal: boolean;
983 /**
984 * The value will be `true` if the decoding result will include the byte order
985 * mark.
986 */
987 readonly ignoreBOM: boolean;
988 constructor(
989 encoding?: string,
990 options?: {
991 fatal?: boolean | undefined;
992 ignoreBOM?: boolean | undefined;
993 }
994 );
995 /**
996 * Decodes the `input` and returns a string. If `options.stream` is `true`, any
997 * incomplete byte sequences occurring at the end of the `input` are buffered
998 * internally and emitted after the next call to `textDecoder.decode()`.
999 *
1000 * If `textDecoder.fatal` is `true`, decoding errors that occur will result in a`TypeError` being thrown.
1001 * @param input An `ArrayBuffer`, `DataView` or `TypedArray` instance containing the encoded data.
1002 */
1003 decode(
1004 input?: NodeJS.ArrayBufferView | ArrayBuffer | null,
1005 options?: {
1006 stream?: boolean | undefined;
1007 }
1008 ): string;
1009 }
1010 export interface EncodeIntoResult {
1011 /**
1012 * The read Unicode code units of input.
1013 */
1014 read: number;
1015 /**
1016 * The written UTF-8 bytes of output.
1017 */
1018 written: number;
1019 }
1020 export { types };
1021 /**
1022 * An implementation of the [WHATWG Encoding Standard](https://encoding.spec.whatwg.org/)`TextEncoder` API. All
1023 * instances of `TextEncoder` only support UTF-8 encoding.
1024 *
1025 * ```js
1026 * const encoder = new TextEncoder();
1027 * const uint8array = encoder.encode('this is some data');
1028 * ```
1029 *
1030 * The `TextEncoder` class is also available on the global object.
1031 * @since v8.3.0
1032 */
1033 export class TextEncoder {
1034 /**
1035 * The encoding supported by the `TextEncoder` instance. Always set to `'utf-8'`.
1036 */
1037 readonly encoding: string;
1038 /**
1039 * UTF-8 encodes the `input` string and returns a `Uint8Array` containing the
1040 * encoded bytes.
1041 * @param [input='an empty string'] The text to encode.
1042 */
1043 encode(input?: string): Uint8Array;
1044 /**
1045 * UTF-8 encodes the `src` string to the `dest` Uint8Array and returns an object
1046 * containing the read Unicode code units and written UTF-8 bytes.
1047 *
1048 * ```js
1049 * const encoder = new TextEncoder();
1050 * const src = 'this is some data';
1051 * const dest = new Uint8Array(10);
1052 * const { read, written } = encoder.encodeInto(src, dest);
1053 * ```
1054 * @param src The text to encode.
1055 * @param dest The array to hold the encode result.
1056 */
1057 encodeInto(src: string, dest: Uint8Array): EncodeIntoResult;
1058 }
1059}
1060declare module 'util/types' {
1061 export * from 'util/types';
1062}
1063declare module 'util/types' {
1064 import { KeyObject, webcrypto } from 'node:crypto';
1065 /**
1066 * Returns `true` if the value is a built-in [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer)
1067 * or[`SharedArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer) instance.
1068 *
1069 * See also `util.types.isArrayBuffer()` and `util.types.isSharedArrayBuffer()`.
1070 *
1071 * ```js
1072 * util.types.isAnyArrayBuffer(new ArrayBuffer()); // Returns true
1073 * util.types.isAnyArrayBuffer(new SharedArrayBuffer()); // Returns true
1074 * ```
1075 * @since v10.0.0
1076 */
1077 function isAnyArrayBuffer(object: unknown): object is ArrayBufferLike;
1078 /**
1079 * Returns `true` if the value is an `arguments` object.
1080 *
1081 * ```js
1082 * function foo() {
1083 * util.types.isArgumentsObject(arguments); // Returns true
1084 * }
1085 * ```
1086 * @since v10.0.0
1087 */
1088 function isArgumentsObject(object: unknown): object is IArguments;
1089 /**
1090 * Returns `true` if the value is a built-in [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer) instance.
1091 * This does _not_ include [`SharedArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer) instances. Usually, it is
1092 * desirable to test for both; See `util.types.isAnyArrayBuffer()` for that.
1093 *
1094 * ```js
1095 * util.types.isArrayBuffer(new ArrayBuffer()); // Returns true
1096 * util.types.isArrayBuffer(new SharedArrayBuffer()); // Returns false
1097 * ```
1098 * @since v10.0.0
1099 */
1100 function isArrayBuffer(object: unknown): object is ArrayBuffer;
1101 /**
1102 * Returns `true` if the value is an instance of one of the [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer)views, such as typed array
1103 * objects or [`DataView`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView). Equivalent
1104 * to[`ArrayBuffer.isView()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/isView).
1105 *
1106 * ```js
1107 * util.types.isArrayBufferView(new Int8Array()); // true
1108 * util.types.isArrayBufferView(Buffer.from('hello world')); // true
1109 * util.types.isArrayBufferView(new DataView(new ArrayBuffer(16))); // true
1110 * util.types.isArrayBufferView(new ArrayBuffer()); // false
1111 * ```
1112 * @since v10.0.0
1113 */
1114 function isArrayBufferView(object: unknown): object is NodeJS.ArrayBufferView;
1115 /**
1116 * Returns `true` if the value is an [async function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function).
1117 * This only reports back what the JavaScript engine is seeing;
1118 * in particular, the return value may not match the original source code if
1119 * a transpilation tool was used.
1120 *
1121 * ```js
1122 * util.types.isAsyncFunction(function foo() {}); // Returns false
1123 * util.types.isAsyncFunction(async function foo() {}); // Returns true
1124 * ```
1125 * @since v10.0.0
1126 */
1127 function isAsyncFunction(object: unknown): boolean;
1128 /**
1129 * Returns `true` if the value is a `BigInt64Array` instance.
1130 *
1131 * ```js
1132 * util.types.isBigInt64Array(new BigInt64Array()); // Returns true
1133 * util.types.isBigInt64Array(new BigUint64Array()); // Returns false
1134 * ```
1135 * @since v10.0.0
1136 */
1137 function isBigInt64Array(value: unknown): value is BigInt64Array;
1138 /**
1139 * Returns `true` if the value is a `BigUint64Array` instance.
1140 *
1141 * ```js
1142 * util.types.isBigUint64Array(new BigInt64Array()); // Returns false
1143 * util.types.isBigUint64Array(new BigUint64Array()); // Returns true
1144 * ```
1145 * @since v10.0.0
1146 */
1147 function isBigUint64Array(value: unknown): value is BigUint64Array;
1148 /**
1149 * Returns `true` if the value is a boolean object, e.g. created
1150 * by `new Boolean()`.
1151 *
1152 * ```js
1153 * util.types.isBooleanObject(false); // Returns false
1154 * util.types.isBooleanObject(true); // Returns false
1155 * util.types.isBooleanObject(new Boolean(false)); // Returns true
1156 * util.types.isBooleanObject(new Boolean(true)); // Returns true
1157 * util.types.isBooleanObject(Boolean(false)); // Returns false
1158 * util.types.isBooleanObject(Boolean(true)); // Returns false
1159 * ```
1160 * @since v10.0.0
1161 */
1162 function isBooleanObject(object: unknown): object is Boolean;
1163 /**
1164 * Returns `true` if the value is any boxed primitive object, e.g. created
1165 * by `new Boolean()`, `new String()` or `Object(Symbol())`.
1166 *
1167 * For example:
1168 *
1169 * ```js
1170 * util.types.isBoxedPrimitive(false); // Returns false
1171 * util.types.isBoxedPrimitive(new Boolean(false)); // Returns true
1172 * util.types.isBoxedPrimitive(Symbol('foo')); // Returns false
1173 * util.types.isBoxedPrimitive(Object(Symbol('foo'))); // Returns true
1174 * util.types.isBoxedPrimitive(Object(BigInt(5))); // Returns true
1175 * ```
1176 * @since v10.11.0
1177 */
1178 function isBoxedPrimitive(object: unknown): object is String | Number | BigInt | Boolean | Symbol;
1179 /**
1180 * Returns `true` if the value is a built-in [`DataView`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView) instance.
1181 *
1182 * ```js
1183 * const ab = new ArrayBuffer(20);
1184 * util.types.isDataView(new DataView(ab)); // Returns true
1185 * util.types.isDataView(new Float64Array()); // Returns false
1186 * ```
1187 *
1188 * See also [`ArrayBuffer.isView()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/isView).
1189 * @since v10.0.0
1190 */
1191 function isDataView(object: unknown): object is DataView;
1192 /**
1193 * Returns `true` if the value is a built-in [`Date`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) instance.
1194 *
1195 * ```js
1196 * util.types.isDate(new Date()); // Returns true
1197 * ```
1198 * @since v10.0.0
1199 */
1200 function isDate(object: unknown): object is Date;
1201 /**
1202 * Returns `true` if the value is a native `External` value.
1203 *
1204 * A native `External` value is a special type of object that contains a
1205 * raw C++ pointer (`void*`) for access from native code, and has no other
1206 * properties. Such objects are created either by Node.js internals or native
1207 * addons. In JavaScript, they are [frozen](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze) objects with a`null` prototype.
1208 *
1209 * ```c
1210 * #include <js_native_api.h>
1211 * #include <stdlib.h>
1212 * napi_value result;
1213 * static napi_value MyNapi(napi_env env, napi_callback_info info) {
1214 * int* raw = (int*) malloc(1024);
1215 * napi_status status = napi_create_external(env, (void*) raw, NULL, NULL, &#x26;result);
1216 * if (status != napi_ok) {
1217 * napi_throw_error(env, NULL, "napi_create_external failed");
1218 * return NULL;
1219 * }
1220 * return result;
1221 * }
1222 * ...
1223 * DECLARE_NAPI_PROPERTY("myNapi", MyNapi)
1224 * ...
1225 * ```
1226 *
1227 * ```js
1228 * const native = require('napi_addon.node');
1229 * const data = native.myNapi();
1230 * util.types.isExternal(data); // returns true
1231 * util.types.isExternal(0); // returns false
1232 * util.types.isExternal(new String('foo')); // returns false
1233 * ```
1234 *
1235 * For further information on `napi_create_external`, refer to `napi_create_external()`.
1236 * @since v10.0.0
1237 */
1238 function isExternal(object: unknown): boolean;
1239 /**
1240 * Returns `true` if the value is a built-in [`Float32Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float32Array) instance.
1241 *
1242 * ```js
1243 * util.types.isFloat32Array(new ArrayBuffer()); // Returns false
1244 * util.types.isFloat32Array(new Float32Array()); // Returns true
1245 * util.types.isFloat32Array(new Float64Array()); // Returns false
1246 * ```
1247 * @since v10.0.0
1248 */
1249 function isFloat32Array(object: unknown): object is Float32Array;
1250 /**
1251 * Returns `true` if the value is a built-in [`Float64Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float64Array) instance.
1252 *
1253 * ```js
1254 * util.types.isFloat64Array(new ArrayBuffer()); // Returns false
1255 * util.types.isFloat64Array(new Uint8Array()); // Returns false
1256 * util.types.isFloat64Array(new Float64Array()); // Returns true
1257 * ```
1258 * @since v10.0.0
1259 */
1260 function isFloat64Array(object: unknown): object is Float64Array;
1261 /**
1262 * Returns `true` if the value is a generator function.
1263 * This only reports back what the JavaScript engine is seeing;
1264 * in particular, the return value may not match the original source code if
1265 * a transpilation tool was used.
1266 *
1267 * ```js
1268 * util.types.isGeneratorFunction(function foo() {}); // Returns false
1269 * util.types.isGeneratorFunction(function* foo() {}); // Returns true
1270 * ```
1271 * @since v10.0.0
1272 */
1273 function isGeneratorFunction(object: unknown): object is GeneratorFunction;
1274 /**
1275 * Returns `true` if the value is a generator object as returned from a
1276 * built-in generator function.
1277 * This only reports back what the JavaScript engine is seeing;
1278 * in particular, the return value may not match the original source code if
1279 * a transpilation tool was used.
1280 *
1281 * ```js
1282 * function* foo() {}
1283 * const generator = foo();
1284 * util.types.isGeneratorObject(generator); // Returns true
1285 * ```
1286 * @since v10.0.0
1287 */
1288 function isGeneratorObject(object: unknown): object is Generator;
1289 /**
1290 * Returns `true` if the value is a built-in [`Int8Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int8Array) instance.
1291 *
1292 * ```js
1293 * util.types.isInt8Array(new ArrayBuffer()); // Returns false
1294 * util.types.isInt8Array(new Int8Array()); // Returns true
1295 * util.types.isInt8Array(new Float64Array()); // Returns false
1296 * ```
1297 * @since v10.0.0
1298 */
1299 function isInt8Array(object: unknown): object is Int8Array;
1300 /**
1301 * Returns `true` if the value is a built-in [`Int16Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int16Array) instance.
1302 *
1303 * ```js
1304 * util.types.isInt16Array(new ArrayBuffer()); // Returns false
1305 * util.types.isInt16Array(new Int16Array()); // Returns true
1306 * util.types.isInt16Array(new Float64Array()); // Returns false
1307 * ```
1308 * @since v10.0.0
1309 */
1310 function isInt16Array(object: unknown): object is Int16Array;
1311 /**
1312 * Returns `true` if the value is a built-in [`Int32Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int32Array) instance.
1313 *
1314 * ```js
1315 * util.types.isInt32Array(new ArrayBuffer()); // Returns false
1316 * util.types.isInt32Array(new Int32Array()); // Returns true
1317 * util.types.isInt32Array(new Float64Array()); // Returns false
1318 * ```
1319 * @since v10.0.0
1320 */
1321 function isInt32Array(object: unknown): object is Int32Array;
1322 /**
1323 * Returns `true` if the value is a built-in [`Map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) instance.
1324 *
1325 * ```js
1326 * util.types.isMap(new Map()); // Returns true
1327 * ```
1328 * @since v10.0.0
1329 */
1330 function isMap<T>(object: T | {}): object is T extends ReadonlyMap<any, any> ? (unknown extends T ? never : ReadonlyMap<any, any>) : Map<unknown, unknown>;
1331 /**
1332 * Returns `true` if the value is an iterator returned for a built-in[`Map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) instance.
1333 *
1334 * ```js
1335 * const map = new Map();
1336 * util.types.isMapIterator(map.keys()); // Returns true
1337 * util.types.isMapIterator(map.values()); // Returns true
1338 * util.types.isMapIterator(map.entries()); // Returns true
1339 * util.types.isMapIterator(map[Symbol.iterator]()); // Returns true
1340 * ```
1341 * @since v10.0.0
1342 */
1343 function isMapIterator(object: unknown): boolean;
1344 /**
1345 * Returns `true` if the value is an instance of a [Module Namespace Object](https://tc39.github.io/ecma262/#sec-module-namespace-exotic-objects).
1346 *
1347 * ```js
1348 * import * as ns from './a.js';
1349 *
1350 * util.types.isModuleNamespaceObject(ns); // Returns true
1351 * ```
1352 * @since v10.0.0
1353 */
1354 function isModuleNamespaceObject(value: unknown): boolean;
1355 /**
1356 * Returns `true` if the value is an instance of a built-in `Error` type.
1357 *
1358 * ```js
1359 * util.types.isNativeError(new Error()); // Returns true
1360 * util.types.isNativeError(new TypeError()); // Returns true
1361 * util.types.isNativeError(new RangeError()); // Returns true
1362 * ```
1363 * @since v10.0.0
1364 */
1365 function isNativeError(object: unknown): object is Error;
1366 /**
1367 * Returns `true` if the value is a number object, e.g. created
1368 * by `new Number()`.
1369 *
1370 * ```js
1371 * util.types.isNumberObject(0); // Returns false
1372 * util.types.isNumberObject(new Number(0)); // Returns true
1373 * ```
1374 * @since v10.0.0
1375 */
1376 function isNumberObject(object: unknown): object is Number;
1377 /**
1378 * Returns `true` if the value is a built-in [`Promise`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise).
1379 *
1380 * ```js
1381 * util.types.isPromise(Promise.resolve(42)); // Returns true
1382 * ```
1383 * @since v10.0.0
1384 */
1385 function isPromise(object: unknown): object is Promise<unknown>;
1386 /**
1387 * Returns `true` if the value is a [`Proxy`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy) instance.
1388 *
1389 * ```js
1390 * const target = {};
1391 * const proxy = new Proxy(target, {});
1392 * util.types.isProxy(target); // Returns false
1393 * util.types.isProxy(proxy); // Returns true
1394 * ```
1395 * @since v10.0.0
1396 */
1397 function isProxy(object: unknown): boolean;
1398 /**
1399 * Returns `true` if the value is a regular expression object.
1400 *
1401 * ```js
1402 * util.types.isRegExp(/abc/); // Returns true
1403 * util.types.isRegExp(new RegExp('abc')); // Returns true
1404 * ```
1405 * @since v10.0.0
1406 */
1407 function isRegExp(object: unknown): object is RegExp;
1408 /**
1409 * Returns `true` if the value is a built-in [`Set`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set) instance.
1410 *
1411 * ```js
1412 * util.types.isSet(new Set()); // Returns true
1413 * ```
1414 * @since v10.0.0
1415 */
1416 function isSet<T>(object: T | {}): object is T extends ReadonlySet<any> ? (unknown extends T ? never : ReadonlySet<any>) : Set<unknown>;
1417 /**
1418 * Returns `true` if the value is an iterator returned for a built-in[`Set`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set) instance.
1419 *
1420 * ```js
1421 * const set = new Set();
1422 * util.types.isSetIterator(set.keys()); // Returns true
1423 * util.types.isSetIterator(set.values()); // Returns true
1424 * util.types.isSetIterator(set.entries()); // Returns true
1425 * util.types.isSetIterator(set[Symbol.iterator]()); // Returns true
1426 * ```
1427 * @since v10.0.0
1428 */
1429 function isSetIterator(object: unknown): boolean;
1430 /**
1431 * Returns `true` if the value is a built-in [`SharedArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer) instance.
1432 * This does _not_ include [`ArrayBuffer`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer) instances. Usually, it is
1433 * desirable to test for both; See `util.types.isAnyArrayBuffer()` for that.
1434 *
1435 * ```js
1436 * util.types.isSharedArrayBuffer(new ArrayBuffer()); // Returns false
1437 * util.types.isSharedArrayBuffer(new SharedArrayBuffer()); // Returns true
1438 * ```
1439 * @since v10.0.0
1440 */
1441 function isSharedArrayBuffer(object: unknown): object is SharedArrayBuffer;
1442 /**
1443 * Returns `true` if the value is a string object, e.g. created
1444 * by `new String()`.
1445 *
1446 * ```js
1447 * util.types.isStringObject('foo'); // Returns false
1448 * util.types.isStringObject(new String('foo')); // Returns true
1449 * ```
1450 * @since v10.0.0
1451 */
1452 function isStringObject(object: unknown): object is String;
1453 /**
1454 * Returns `true` if the value is a symbol object, created
1455 * by calling `Object()` on a `Symbol` primitive.
1456 *
1457 * ```js
1458 * const symbol = Symbol('foo');
1459 * util.types.isSymbolObject(symbol); // Returns false
1460 * util.types.isSymbolObject(Object(symbol)); // Returns true
1461 * ```
1462 * @since v10.0.0
1463 */
1464 function isSymbolObject(object: unknown): object is Symbol;
1465 /**
1466 * Returns `true` if the value is a built-in [`TypedArray`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray) instance.
1467 *
1468 * ```js
1469 * util.types.isTypedArray(new ArrayBuffer()); // Returns false
1470 * util.types.isTypedArray(new Uint8Array()); // Returns true
1471 * util.types.isTypedArray(new Float64Array()); // Returns true
1472 * ```
1473 *
1474 * See also [`ArrayBuffer.isView()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/isView).
1475 * @since v10.0.0
1476 */
1477 function isTypedArray(object: unknown): object is NodeJS.TypedArray;
1478 /**
1479 * Returns `true` if the value is a built-in [`Uint8Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array) instance.
1480 *
1481 * ```js
1482 * util.types.isUint8Array(new ArrayBuffer()); // Returns false
1483 * util.types.isUint8Array(new Uint8Array()); // Returns true
1484 * util.types.isUint8Array(new Float64Array()); // Returns false
1485 * ```
1486 * @since v10.0.0
1487 */
1488 function isUint8Array(object: unknown): object is Uint8Array;
1489 /**
1490 * Returns `true` if the value is a built-in [`Uint8ClampedArray`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8ClampedArray) instance.
1491 *
1492 * ```js
1493 * util.types.isUint8ClampedArray(new ArrayBuffer()); // Returns false
1494 * util.types.isUint8ClampedArray(new Uint8ClampedArray()); // Returns true
1495 * util.types.isUint8ClampedArray(new Float64Array()); // Returns false
1496 * ```
1497 * @since v10.0.0
1498 */
1499 function isUint8ClampedArray(object: unknown): object is Uint8ClampedArray;
1500 /**
1501 * Returns `true` if the value is a built-in [`Uint16Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint16Array) instance.
1502 *
1503 * ```js
1504 * util.types.isUint16Array(new ArrayBuffer()); // Returns false
1505 * util.types.isUint16Array(new Uint16Array()); // Returns true
1506 * util.types.isUint16Array(new Float64Array()); // Returns false
1507 * ```
1508 * @since v10.0.0
1509 */
1510 function isUint16Array(object: unknown): object is Uint16Array;
1511 /**
1512 * Returns `true` if the value is a built-in [`Uint32Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array) instance.
1513 *
1514 * ```js
1515 * util.types.isUint32Array(new ArrayBuffer()); // Returns false
1516 * util.types.isUint32Array(new Uint32Array()); // Returns true
1517 * util.types.isUint32Array(new Float64Array()); // Returns false
1518 * ```
1519 * @since v10.0.0
1520 */
1521 function isUint32Array(object: unknown): object is Uint32Array;
1522 /**
1523 * Returns `true` if the value is a built-in [`WeakMap`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap) instance.
1524 *
1525 * ```js
1526 * util.types.isWeakMap(new WeakMap()); // Returns true
1527 * ```
1528 * @since v10.0.0
1529 */
1530 function isWeakMap(object: unknown): object is WeakMap<object, unknown>;
1531 /**
1532 * Returns `true` if the value is a built-in [`WeakSet`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet) instance.
1533 *
1534 * ```js
1535 * util.types.isWeakSet(new WeakSet()); // Returns true
1536 * ```
1537 * @since v10.0.0
1538 */
1539 function isWeakSet(object: unknown): object is WeakSet<object>;
1540 /**
1541 * Returns `true` if `value` is a `<KeyObject>`, `false` otherwise.
1542 * @since v16.2.0
1543 */
1544 function isKeyObject(object: unknown): object is KeyObject;
1545 /**
1546 * Returns `true` if `value` is a `<CryptoKey>`, `false` otherwise.
1547 * @since v16.2.0
1548 */
1549 function isCryptoKey(object: unknown): object is webcrypto.CryptoKey;
1550}
1551declare module 'node:util' {
1552 export * from 'util';
1553}
1554declare module 'node:util/types' {
1555 export * from 'util/types';
1556}