util.d.ts

/**
 * The `util` module supports the needs of Node.js internal APIs. Many of the
 * utilities are useful for application and module developers as well. To access
 * it:
 *
 * ```js
 * const util = require('util');
 * ```
 * @see [source](https://github.com/nodejs/node/blob/v18.0.0/lib/util.js)
 */
declare module "util" {
  export interface InspectOptions {
    /**
     * If set to `true`, getters are going to be
     * inspected as well. If set to `'get'` only getters without setter are going
     * to be inspected. If set to `'set'` only getters having a corresponding
     * setter are going to be inspected. This might cause side effects depending on
     * the getter function.
     * @default `false`
     */
    getters?: "get" | "set" | boolean | undefined;
    showHidden?: boolean | undefined;
    /**
     * @default 2
     */
    depth?: number | null | undefined;
    colors?: boolean | undefined;
    customInspect?: boolean | undefined;
    showProxy?: boolean | undefined;
    maxArrayLength?: number | null | undefined;
    /**
     * Specifies the maximum number of characters to
     * include when formatting. Set to `null` or `Infinity` to show all elements.
     * Set to `0` or negative to show no characters.
     * @default 10000
     */
    maxStringLength?: number | null | undefined;
    breakLength?: number | undefined;
    /**
     * Setting this to `false` causes each object key
     * to be displayed on a new line. It will also add new lines to text that is
     * longer than `breakLength`. If set to a number, the most `n` inner elements
     * are united on a single line as long as all properties fit into
     * `breakLength`. Short array elements are also grouped together. Note that no
     * text will be reduced below 16 characters, no matter the `breakLength` size.
     * For more information, see the example below.
     * @default `true`
     */
    compact?: boolean | number | undefined;
    sorted?: boolean | ((a: string, b: string) => number) | undefined;
  }
  export type Style =
    | "special"
    | "number"
    | "bigint"
    | "boolean"
    | "undefined"
    | "null"
    | "string"
    | "symbol"
    | "date"
    | "regexp"
    | "module";
  export type CustomInspectFunction = (
    depth: number,
    options: InspectOptionsStylized
  ) => string;
  export interface InspectOptionsStylized extends InspectOptions {
    stylize(text: string, styleType: Style): string;
  }
  /**
   * The `util.format()` method returns a formatted string using the first argument
   * as a `printf`\-like format string which can contain zero or more format
   * specifiers. Each specifier is replaced with the converted value from the
   * corresponding argument. Supported specifiers are:
   *
   * If a specifier does not have a corresponding argument, it is not replaced:
   *
   * ```js
   * util.format('%s:%s', 'foo');
   * // Returns: 'foo:%s'
   * ```
   *
   * Values that are not part of the format string are formatted using`util.inspect()` if their type is not `string`.
   *
   * If there are more arguments passed to the `util.format()` method than the
   * number of specifiers, the extra arguments are concatenated to the returned
   * string, separated by spaces:
   *
   * ```js
   * util.format('%s:%s', 'foo', 'bar', 'baz');
   * // Returns: 'foo:bar baz'
   * ```
   *
   * 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:
   *
   * ```js
   * util.format(1, 2, 3);
   * // Returns: '1 2 3'
   * ```
   *
   * If only one argument is passed to `util.format()`, it is returned as it is
   * without any formatting:
   *
   * ```js
   * util.format('%% %s');
   * // Returns: '%% %s'
   * ```
   *
   * `util.format()` is a synchronous method that is intended as a debugging tool.
   * Some input values can have a significant performance overhead that can block the
   * event loop. Use this function with care and never in a hot code path.
   * @param format A `printf`-like format string.
   */
  export function format(format?: any, ...param: any[]): string;
  /**
   * This function is identical to {@link format}, except in that it takes
   * an `inspectOptions` argument which specifies options that are passed along to {@link inspect}.
   *
   * ```js
   * util.formatWithOptions({ colors: true }, 'See object %O', { foo: 42 });
   * // Returns 'See object { foo: 42 }', where `42` is colored as a number
   * // when printed to a terminal.
   * ```
   */
  // FIXME: util.formatWithOptions is typed, but is not defined in the polyfill
  // export function formatWithOptions(inspectOptions: InspectOptions, format?: any, ...param: any[]): string;
  /**
   * Returns the string name for a numeric error code that comes from a Node.js API.
   * The mapping between error codes and error names is platform-dependent.
   * See `Common System Errors` for the names of common errors.
   *
   * ```js
   * fs.access('file/that/does/not/exist', (err) => {
   *   const name = util.getSystemErrorName(err.errno);
   *   console.error(name);  // ENOENT
   * });
   * ```
   */
  // FIXME: util.getSystemErrorName is typed, but is not defined in the polyfill
  // export function getSystemErrorName(err: number): string;
  /**
   * Returns a Map of all system error codes available from the Node.js API.
   * The mapping between error codes and error names is platform-dependent.
   * See `Common System Errors` for the names of common errors.
   *
   * ```js
   * fs.access('file/that/does/not/exist', (err) => {
   *   const errorMap = util.getSystemErrorMap();
   *   const name = errorMap.get(err.errno);
   *   console.error(name);  // ENOENT
   * });
   * ```
   */
  // FIXME: util.getSystemErrorMap is typed, but is not defined in the polyfill
  // export function getSystemErrorMap(): Map<number, [string, string]>;
  /**
   * The `util.log()` method prints the given `string` to `stdout` with an included
   * timestamp.
   *
   * ```js
   * const util = require('util');
   *
   * util.log('Timestamped message.');
   * ```
   * @deprecated Since v6.0.0 - Use a third party module instead.
   */
  export function log(string: string): void;
  /**
   * Returns the `string` after replacing any surrogate code points
   * (or equivalently, any unpaired surrogate code units) with the
   * Unicode "replacement character" U+FFFD.
   */
  // FIXME: util.toUSVString is typed, but is not defined in the polyfill
  // export function toUSVString(string: string): string;
  /**
   * The `util.inspect()` method returns a string representation of `object` that is
   * intended for debugging. The output of `util.inspect` may change at any time
   * and should not be depended upon programmatically. Additional `options` may be
   * passed that alter the result.`util.inspect()` will use the constructor's name and/or `@@toStringTag` to make
   * an identifiable tag for an inspected value.
   *
   * ```js
   * class Foo {
   *   get [Symbol.toStringTag]() {
   *     return 'bar';
   *   }
   * }
   *
   * class Bar {}
   *
   * const baz = Object.create(null, { [Symbol.toStringTag]: { value: 'foo' } });
   *
   * util.inspect(new Foo()); // 'Foo [bar] {}'
   * util.inspect(new Bar()); // 'Bar {}'
   * util.inspect(baz);       // '[foo] {}'
   * ```
   *
   * Circular references point to their anchor by using a reference index:
   *
   * ```js
   * const { inspect } = require('util');
   *
   * const obj = {};
   * obj.a = [obj];
   * obj.b = {};
   * obj.b.inner = obj.b;
   * obj.b.obj = obj;
   *
   * console.log(inspect(obj));
   * // <ref *1> {
   * //   a: [ [Circular *1] ],
   * //   b: <ref *2> { inner: [Circular *2], obj: [Circular *1] }
   * // }
   * ```
   *
   * The following example inspects all properties of the `util` object:
   *
   * ```js
   * const util = require('util');
   *
   * console.log(util.inspect(util, { showHidden: true, depth: null }));
   * ```
   *
   * The following example highlights the effect of the `compact` option:
   *
   * ```js
   * const util = require('util');
   *
   * const o = {
   *   a: [1, 2, [[
   *     'Lorem ipsum dolor sit amet,\nconsectetur adipiscing elit, sed do ' +
   *       'eiusmod \ntempor incididunt ut labore et dolore magna aliqua.',
   *     'test',
   *     'foo']], 4],
   *   b: new Map([['za', 1], ['zb', 'test']])
   * };
   * console.log(util.inspect(o, { compact: true, depth: 5, breakLength: 80 }));
   *
   * // { a:
   * //   [ 1,
   * //     2,
   * //     [ [ 'Lorem ipsum dolor sit amet,\nconsectetur [...]', // A long line
   * //           'test',
   * //           'foo' ] ],
   * //     4 ],
   * //   b: Map(2) { 'za' => 1, 'zb' => 'test' } }
   *
   * // Setting `compact` to false or an integer creates more reader friendly output.
   * console.log(util.inspect(o, { compact: false, depth: 5, breakLength: 80 }));
   *
   * // {
   * //   a: [
   * //     1,
   * //     2,
   * //     [
   * //       [
   * //         'Lorem ipsum dolor sit amet,\n' +
   * //           'consectetur adipiscing elit, sed do eiusmod \n' +
   * //           'tempor incididunt ut labore et dolore magna aliqua.',
   * //         'test',
   * //         'foo'
   * //       ]
   * //     ],
   * //     4
   * //   ],
   * //   b: Map(2) {
   * //     'za' => 1,
   * //     'zb' => 'test'
   * //   }
   * // }
   *
   * // Setting `breakLength` to e.g. 150 will print the "Lorem ipsum" text in a
   * // single line.
   * ```
   *
   * The `showHidden` option allows [`WeakMap`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap) and
   * [`WeakSet`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet) entries to be
   * inspected. If there are more entries than `maxArrayLength`, there is no
   * 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
   * result in different output. Furthermore, entries
   * with no remaining strong references may be garbage collected at any time.
   *
   * ```js
   * const { inspect } = require('util');
   *
   * const obj = { a: 1 };
   * const obj2 = { b: 2 };
   * const weakSet = new WeakSet([obj, obj2]);
   *
   * console.log(inspect(weakSet, { showHidden: true }));
   * // WeakSet { { a: 1 }, { b: 2 } }
   * ```
   *
   * The `sorted` option ensures that an object's property insertion order does not
   * impact the result of `util.inspect()`.
   *
   * ```js
   * const { inspect } = require('util');
   * const assert = require('assert');
   *
   * const o1 = {
   *   b: [2, 3, 1],
   *   a: '`a` comes before `b`',
   *   c: new Set([2, 3, 1])
   * };
   * console.log(inspect(o1, { sorted: true }));
   * // { a: '`a` comes before `b`', b: [ 2, 3, 1 ], c: Set(3) { 1, 2, 3 } }
   * console.log(inspect(o1, { sorted: (a, b) => b.localeCompare(a) }));
   * // { c: Set(3) { 3, 2, 1 }, b: [ 2, 3, 1 ], a: '`a` comes before `b`' }
   *
   * const o2 = {
   *   c: new Set([2, 1, 3]),
   *   a: '`a` comes before `b`',
   *   b: [2, 3, 1]
   * };
   * assert.strict.equal(
   *   inspect(o1, { sorted: true }),
   *   inspect(o2, { sorted: true })
   * );
   * ```
   *
   * The `numericSeparator` option adds an underscore every three digits to all
   * numbers.
   *
   * ```js
   * const { inspect } = require('util');
   *
   * const thousand = 1_000;
   * const million = 1_000_000;
   * const bigNumber = 123_456_789n;
   * const bigDecimal = 1_234.123_45;
   *
   * console.log(thousand, million, bigNumber, bigDecimal);
   * // 1_000 1_000_000 123_456_789n 1_234.123_45
   * ```
   *
   * `util.inspect()` is a synchronous method intended for debugging. Its maximum
   * output length is approximately 128 MB. Inputs that result in longer output will
   * be truncated.
   * @param object Any JavaScript primitive or `Object`.
   * @return The representation of `object`.
   */
  export function inspect(
    object: any,
    showHidden?: boolean,
    depth?: number | null,
    color?: boolean
  ): string;
  export function inspect(object: any, options?: InspectOptions): string;
  export namespace inspect {
    let colors: Dict<[number, number]>;
    let styles: {
      [K in Style]: string;
    };
    let defaultOptions: InspectOptions;
    /**
     * Allows changing inspect settings from the repl.
     */
    let replDefaults: InspectOptions;
    /**
     * That can be used to declare custom inspect functions.
     */
    const custom: unique symbol;
  }
  /**
   * Alias for [`Array.isArray()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray).
   *
   * Returns `true` if the given `object` is an `Array`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isArray([]);
   * // Returns: true
   * util.isArray(new Array());
   * // Returns: true
   * util.isArray({});
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Use `isArray` instead.
   */
  export function isArray(object: unknown): object is unknown[];
  /**
   * Returns `true` if the given `object` is a `RegExp`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isRegExp(/some regexp/);
   * // Returns: true
   * util.isRegExp(new RegExp('another regexp'));
   * // Returns: true
   * util.isRegExp({});
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Deprecated
   */
  export function isRegExp(object: unknown): object is RegExp;
  /**
   * Returns `true` if the given `object` is a `Date`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isDate(new Date());
   * // Returns: true
   * util.isDate(Date());
   * // false (without 'new' returns a String)
   * util.isDate({});
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Use {@link types.isDate} instead.
   */
  export function isDate(object: unknown): object is Date;
  /**
   * Returns `true` if the given `object` is an `Error`. Otherwise, returns`false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isError(new Error());
   * // Returns: true
   * util.isError(new TypeError());
   * // Returns: true
   * util.isError({ name: 'Error', message: 'an error occurred' });
   * // Returns: false
   * ```
   *
   * This method relies on `Object.prototype.toString()` behavior. It is
   * possible to obtain an incorrect result when the `object` argument manipulates`@@toStringTag`.
   *
   * ```js
   * const util = require('util');
   * const obj = { name: 'Error', message: 'an error occurred' };
   *
   * util.isError(obj);
   * // Returns: false
   * obj[Symbol.toStringTag] = 'Error';
   * util.isError(obj);
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use {@link types.isNativeError} instead.
   */
  export function isError(object: unknown): object is Error;
  /**
   * Usage of `util.inherits()` is discouraged. Please use the ES6 `class` and`extends` keywords to get language level inheritance support. Also note
   * that the two styles are [semantically incompatible](https://github.com/nodejs/node/issues/4179).
   *
   * Inherit the prototype methods from one [constructor](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/constructor) into another. The
   * prototype of `constructor` will be set to a new object created from`superConstructor`.
   *
   * This mainly adds some input validation on top of`Object.setPrototypeOf(constructor.prototype, superConstructor.prototype)`.
   * As an additional convenience, `superConstructor` will be accessible
   * through the `constructor.super_` property.
   *
   * ```js
   * const util = require('util');
   * const EventEmitter = require('events');
   *
   * function MyStream() {
   *   EventEmitter.call(this);
   * }
   *
   * util.inherits(MyStream, EventEmitter);
   *
   * MyStream.prototype.write = function(data) {
   *   this.emit('data', data);
   * };
   *
   * const stream = new MyStream();
   *
   * console.log(stream instanceof EventEmitter); // true
   * console.log(MyStream.super_ === EventEmitter); // true
   *
   * stream.on('data', (data) => {
   *   console.log(`Received data: "${data}"`);
   * });
   * stream.write('It works!'); // Received data: "It works!"
   * ```
   *
   * ES6 example using `class` and `extends`:
   *
   * ```js
   * const EventEmitter = require('events');
   *
   * class MyStream extends EventEmitter {
   *   write(data) {
   *     this.emit('data', data);
   *   }
   * }
   *
   * const stream = new MyStream();
   *
   * stream.on('data', (data) => {
   *   console.log(`Received data: "${data}"`);
   * });
   * stream.write('With ES6');
   * ```
   * @deprecated Legacy: Use ES2015 class syntax and `extends` keyword instead.
   */
  export function inherits(
    constructor: unknown,
    superConstructor: unknown
  ): void;
  export type DebugLoggerFunction = (msg: string, ...param: unknown[]) => void;
  export interface DebugLogger extends DebugLoggerFunction {
    enabled: boolean;
  }
  /**
   * The `util.debuglog()` method is used to create a function that conditionally
   * 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
   * environment variable, then the returned function operates similar to `console.error()`. If not, then the returned function is a no-op.
   *
   * ```js
   * const util = require('util');
   * const debuglog = util.debuglog('foo');
   *
   * debuglog('hello from foo [%d]', 123);
   * ```
   *
   * If this program is run with `NODE_DEBUG=foo` in the environment, then
   * it will output something like:
   *
   * ```console
   * FOO 3245: hello from foo [123]
   * ```
   *
   * where `3245` is the process id. If it is not run with that
   * environment variable set, then it will not print anything.
   *
   * The `section` supports wildcard also:
   *
   * ```js
   * const util = require('util');
   * const debuglog = util.debuglog('foo-bar');
   *
   * debuglog('hi there, it\'s foo-bar [%d]', 2333);
   * ```
   *
   * if it is run with `NODE_DEBUG=foo*` in the environment, then it will output
   * something like:
   *
   * ```console
   * FOO-BAR 3257: hi there, it's foo-bar [2333]
   * ```
   *
   * Multiple comma-separated `section` names may be specified in the `NODE_DEBUG`environment variable: `NODE_DEBUG=fs,net,tls`.
   *
   * The optional `callback` argument can be used to replace the logging function
   * with a different function that doesn't have any initialization or
   * unnecessary wrapping.
   *
   * ```js
   * const util = require('util');
   * let debuglog = util.debuglog('internals', (debug) => {
   *   // Replace with a logging function that optimizes out
   *   // testing if the section is enabled
   *   debuglog = debug;
   * });
   * ```
   * @param section A string identifying the portion of the application for which the `debuglog` function is being created.
   * @param callback A callback invoked the first time the logging function is called with a function argument that is a more optimized logging function.
   * @return The logging function
   */
  export function debuglog(
    section: string,
    callback?: (fn: DebugLoggerFunction) => void
  ): DebugLogger;
  export const debug: typeof debuglog;
  /**
   * Returns `true` if the given `object` is a `Boolean`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isBoolean(1);
   * // Returns: false
   * util.isBoolean(0);
   * // Returns: false
   * util.isBoolean(false);
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `typeof value === 'boolean'` instead.
   */
  export function isBoolean(object: unknown): object is boolean;
  /**
   * Returns `true` if the given `object` is a `Buffer`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isBuffer({ length: 0 });
   * // Returns: false
   * util.isBuffer([]);
   * // Returns: false
   * util.isBuffer(Buffer.from('hello world'));
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `isBuffer` instead.
   */
  export function isBuffer(object: unknown): object is Buffer;
  /**
   * Returns `true` if the given `object` is a `Function`. Otherwise, returns`false`.
   *
   * ```js
   * const util = require('util');
   *
   * function Foo() {}
   * const Bar = () => {};
   *
   * util.isFunction({});
   * // Returns: false
   * util.isFunction(Foo);
   * // Returns: true
   * util.isFunction(Bar);
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `typeof value === 'function'` instead.
   */
  export function isFunction(object: unknown): boolean;
  /**
   * Returns `true` if the given `object` is strictly `null`. Otherwise, returns`false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isNull(0);
   * // Returns: false
   * util.isNull(undefined);
   * // Returns: false
   * util.isNull(null);
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `value === null` instead.
   */
  export function isNull(object: unknown): object is null;
  /**
   * Returns `true` if the given `object` is `null` or `undefined`. Otherwise,
   * returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isNullOrUndefined(0);
   * // Returns: false
   * util.isNullOrUndefined(undefined);
   * // Returns: true
   * util.isNullOrUndefined(null);
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `value === undefined || value === null` instead.
   */
  export function isNullOrUndefined(
    object: unknown
  ): object is null | undefined;
  /**
   * Returns `true` if the given `object` is a `Number`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isNumber(false);
   * // Returns: false
   * util.isNumber(Infinity);
   * // Returns: true
   * util.isNumber(0);
   * // Returns: true
   * util.isNumber(NaN);
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `typeof value === 'number'` instead.
   */
  export function isNumber(object: unknown): object is number;
  /**
   * Returns `true` if the given `object` is strictly an `Object`**and** not a`Function` (even though functions are objects in JavaScript).
   * Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isObject(5);
   * // Returns: false
   * util.isObject(null);
   * // Returns: false
   * util.isObject({});
   * // Returns: true
   * util.isObject(() => {});
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Deprecated: Use `value !== null && typeof value === 'object'` instead.
   */
  export function isObject(object: unknown): boolean;
  /**
   * Returns `true` if the given `object` is a primitive type. Otherwise, returns`false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isPrimitive(5);
   * // Returns: true
   * util.isPrimitive('foo');
   * // Returns: true
   * util.isPrimitive(false);
   * // Returns: true
   * util.isPrimitive(null);
   * // Returns: true
   * util.isPrimitive(undefined);
   * // Returns: true
   * util.isPrimitive({});
   * // Returns: false
   * util.isPrimitive(() => {});
   * // Returns: false
   * util.isPrimitive(/^$/);
   * // Returns: false
   * util.isPrimitive(new Date());
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Use `(typeof value !== 'object' && typeof value !== 'function') || value === null` instead.
   */
  export function isPrimitive(object: unknown): boolean;
  /**
   * Returns `true` if the given `object` is a `string`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isString('');
   * // Returns: true
   * util.isString('foo');
   * // Returns: true
   * util.isString(String('foo'));
   * // Returns: true
   * util.isString(5);
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Use `typeof value === 'string'` instead.
   */
  export function isString(object: unknown): object is string;
  /**
   * Returns `true` if the given `object` is a `Symbol`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * util.isSymbol(5);
   * // Returns: false
   * util.isSymbol('foo');
   * // Returns: false
   * util.isSymbol(Symbol('foo'));
   * // Returns: true
   * ```
   * @deprecated Since v4.0.0 - Use `typeof value === 'symbol'` instead.
   */
  export function isSymbol(object: unknown): object is symbol;
  /**
   * Returns `true` if the given `object` is `undefined`. Otherwise, returns `false`.
   *
   * ```js
   * const util = require('util');
   *
   * const foo = undefined;
   * util.isUndefined(5);
   * // Returns: false
   * util.isUndefined(foo);
   * // Returns: true
   * util.isUndefined(null);
   * // Returns: false
   * ```
   * @deprecated Since v4.0.0 - Use `value === undefined` instead.
   */
  export function isUndefined(object: unknown): object is undefined;
  /**
   * The `util.deprecate()` method wraps `fn` (which may be a function or class) in
   * such a way that it is marked as deprecated.
   *
   * ```js
   * const util = require('util');
   *
   * exports.obsoleteFunction = util.deprecate(() => {
   *   // Do something here.
   * }, 'obsoleteFunction() is deprecated. Use newShinyFunction() instead.');
   * ```
   *
   * When called, `util.deprecate()` will return a function that will emit a`DeprecationWarning` using the `'warning'` event. The warning will
   * be emitted and printed to `stderr` the first time the returned function is
   * called. After the warning is emitted, the wrapped function is called without
   * emitting a warning.
   *
   * If the same optional `code` is supplied in multiple calls to `util.deprecate()`,
   * the warning will be emitted only once for that `code`.
   *
   * ```js
   * const util = require('util');
   *
   * const fn1 = util.deprecate(someFunction, someMessage, 'DEP0001');
   * const fn2 = util.deprecate(someOtherFunction, someOtherMessage, 'DEP0001');
   * fn1(); // Emits a deprecation warning with code DEP0001
   * fn2(); // Does not emit a deprecation warning because it has the same code
   * ```
   *
   * If either the `--no-deprecation` or `--no-warnings` command-line flags are
   * used, or if the `process.noDeprecation` property is set to `true`_prior_ to
   * the first deprecation warning, the `util.deprecate()` method does nothing.
   *
   * If the `--trace-deprecation` or `--trace-warnings` command-line flags are set,
   * or the `process.traceDeprecation` property is set to `true`, a warning and a
   * stack trace are printed to `stderr` the first time the deprecated function is
   * called.
   *
   * If the `--throw-deprecation` command-line flag is set, or the`process.throwDeprecation` property is set to `true`, then an exception will be
   * thrown when the deprecated function is called.
   *
   * The `--throw-deprecation` command-line flag and `process.throwDeprecation`property take precedence over `--trace-deprecation` and`process.traceDeprecation`.
   * @param fn The function that is being deprecated.
   * @param msg A warning message to display when the deprecated function is invoked.
   * @param code A deprecation code. See the `list of deprecated APIs` for a list of codes.
   * @return The deprecated function wrapped to emit a warning.
   */
  export function deprecate<T extends Function>(
    fn: T,
    msg: string,
    code?: string
  ): T;
  /**
   * Returns `true` if there is deep strict equality between `val1` and `val2`.
   * Otherwise, returns `false`.
   *
   * See `assert.deepStrictEqual()` for more information about deep strict
   * equality.
   */
  export function isDeepStrictEqual(val1: unknown, val2: unknown): boolean;
  /**
   * Returns `str` with any ANSI escape codes removed.
   *
   * ```js
   * console.log(util.stripVTControlCharacters('\u001B[4mvalue\u001B[0m'));
   * // Prints "value"
   * ```
   */
  // FIXME: util.stripVTControlCharacters is typed, but is not defined in the polyfill
  // export function stripVTControlCharacters(str: string): string;
  /**
   * Takes an `async` function (or a function that returns a `Promise`) and returns a
   * function following the error-first callback style, i.e. taking
   * an `(err, value) => ...` callback as the last argument. In the callback, the
   * first argument will be the rejection reason (or `null` if the `Promise`resolved), and the second argument will be the resolved value.
   *
   * ```js
   * const util = require('util');
   *
   * async function fn() {
   *   return 'hello world';
   * }
   * const callbackFunction = util.callbackify(fn);
   *
   * callbackFunction((err, ret) => {
   *   if (err) throw err;
   *   console.log(ret);
   * });
   * ```
   *
   * Will print:
   *
   * ```text
   * hello world
   * ```
   *
   * The callback is executed asynchronously, and will have a limited stack trace.
   * If the callback throws, the process will emit an `'uncaughtException'` event, and if not handled will exit.
   *
   * Since `null` has a special meaning as the first argument to a callback, if a
   * wrapped function rejects a `Promise` with a falsy value as a reason, the value
   * is wrapped in an `Error` with the original value stored in a field named`reason`.
   *
   * ```js
   * function fn() {
   *   return Promise.reject(null);
   * }
   * const callbackFunction = util.callbackify(fn);
   *
   * callbackFunction((err, ret) => {
   *   // When the Promise was rejected with `null` it is wrapped with an Error and
   *   // the original value is stored in `reason`.
   *   err &#x26;&#x26; Object.hasOwn(err, 'reason') &#x26;&#x26; err.reason === null;  // true
   * });
   * ```
   * @param original An `async` function
   * @return a callback style function
   */
  export function callbackify(
    fn: () => Promise<void>
  ): (callback: (err: ErrnoException) => void) => void;
  export function callbackify<TResult>(
    fn: () => Promise<TResult>
  ): (callback: (err: ErrnoException, result: TResult) => void) => void;
  export function callbackify<T1>(
    fn: (arg1: T1) => Promise<void>
  ): (arg1: T1, callback: (err: ErrnoException) => void) => void;
  export function callbackify<T1, TResult>(
    fn: (arg1: T1) => Promise<TResult>
  ): (
    arg1: T1,
    callback: (err: ErrnoException, result: TResult) => void
  ) => void;
  export function callbackify<T1, T2>(
    fn: (arg1: T1, arg2: T2) => Promise<void>
  ): (arg1: T1, arg2: T2, callback: (err: ErrnoException) => void) => void;
  export function callbackify<T1, T2, TResult>(
    fn: (arg1: T1, arg2: T2) => Promise<TResult>
  ): (
    arg1: T1,
    arg2: T2,
    callback: (err: ErrnoException | null, result: TResult) => void
  ) => void;
  export function callbackify<T1, T2, T3>(
    fn: (arg1: T1, arg2: T2, arg3: T3) => Promise<void>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    callback: (err: ErrnoException) => void
  ) => void;
  export function callbackify<T1, T2, T3, TResult>(
    fn: (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    callback: (err: ErrnoException | null, result: TResult) => void
  ) => void;
  export function callbackify<T1, T2, T3, T4>(
    fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    arg4: T4,
    callback: (err: ErrnoException) => void
  ) => void;
  export function callbackify<T1, T2, T3, T4, TResult>(
    fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    arg4: T4,
    callback: (err: ErrnoException | null, result: TResult) => void
  ) => void;
  export function callbackify<T1, T2, T3, T4, T5>(
    fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    arg4: T4,
    arg5: T5,
    callback: (err: ErrnoException) => void
  ) => void;
  export function callbackify<T1, T2, T3, T4, T5, TResult>(
    fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    arg4: T4,
    arg5: T5,
    callback: (err: ErrnoException | null, result: TResult) => void
  ) => void;
  export function callbackify<T1, T2, T3, T4, T5, T6>(
    fn: (
      arg1: T1,
      arg2: T2,
      arg3: T3,
      arg4: T4,
      arg5: T5,
      arg6: T6
    ) => Promise<void>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    arg4: T4,
    arg5: T5,
    arg6: T6,
    callback: (err: ErrnoException) => void
  ) => void;
  export function callbackify<T1, T2, T3, T4, T5, T6, TResult>(
    fn: (
      arg1: T1,
      arg2: T2,
      arg3: T3,
      arg4: T4,
      arg5: T5,
      arg6: T6
    ) => Promise<TResult>
  ): (
    arg1: T1,
    arg2: T2,
    arg3: T3,
    arg4: T4,
    arg5: T5,
    arg6: T6,
    callback: (err: ErrnoException | null, result: TResult) => void
  ) => void;
  export interface CustomPromisifyLegacy<TCustom extends Function>
    extends Function {
    __promisify__: TCustom;
  }
  export interface CustomPromisifySymbol<TCustom extends Function>
    extends Function {
    [promisify.custom]: TCustom;
  }
  export type CustomPromisify<TCustom extends Function> =
    | CustomPromisifySymbol<TCustom>
    | CustomPromisifyLegacy<TCustom>;
  /**
   * Takes a function following the common error-first callback style, i.e. taking
   * an `(err, value) => ...` callback as the last argument, and returns a version
   * that returns promises.
   *
   * ```js
   * const util = require('util');
   * const fs = require('fs');
   *
   * const stat = util.promisify(fs.stat);
   * stat('.').then((stats) => {
   *   // Do something with `stats`
   * }).catch((error) => {
   *   // Handle the error.
   * });
   * ```
   *
   * Or, equivalently using `async function`s:
   *
   * ```js
   * const util = require('util');
   * const fs = require('fs');
   *
   * const stat = util.promisify(fs.stat);
   *
   * async function callStat() {
   *   const stats = await stat('.');
   *   console.log(`This directory is owned by ${stats.uid}`);
   * }
   * ```
   *
   * If there is an `original[util.promisify.custom]` property present, `promisify`will return its value, see `Custom promisified functions`.
   *
   * `promisify()` assumes that `original` is a function taking a callback as its
   * 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
   * an error-first callback, it will still be passed an error-first
   * callback as its last argument.
   *
   * Using `promisify()` on class methods or other methods that use `this` may not
   * work as expected unless handled specially:
   *
   * ```js
   * const util = require('util');
   *
   * class Foo {
   *   constructor() {
   *     this.a = 42;
   *   }
   *
   *   bar(callback) {
   *     callback(null, this.a);
   *   }
   * }
   *
   * const foo = new Foo();
   *
   * const naiveBar = util.promisify(foo.bar);
   * // TypeError: Cannot read property 'a' of undefined
   * // naiveBar().then(a => console.log(a));
   *
   * naiveBar.call(foo).then((a) => console.log(a)); // '42'
   *
   * const bindBar = naiveBar.bind(foo);
   * bindBar().then((a) => console.log(a)); // '42'
   * ```
   */
  export function promisify<TCustom extends Function>(
    fn: CustomPromisify<TCustom>
  ): TCustom;
  export function promisify<TResult>(
    fn: (callback: (err: any, result: TResult) => void) => void
  ): () => Promise<TResult>;
  export function promisify(
    fn: (callback: (err?: any) => void) => void
  ): () => Promise<void>;
  export function promisify<T1, TResult>(
    fn: (arg1: T1, callback: (err: any, result: TResult) => void) => void
  ): (arg1: T1) => Promise<TResult>;
  export function promisify<T1>(
    fn: (arg1: T1, callback: (err?: any) => void) => void
  ): (arg1: T1) => Promise<void>;
  export function promisify<T1, T2, TResult>(
    fn: (
      arg1: T1,
      arg2: T2,
      callback: (err: any, result: TResult) => void
    ) => void
  ): (arg1: T1, arg2: T2) => Promise<TResult>;
  export function promisify<T1, T2>(
    fn: (arg1: T1, arg2: T2, callback: (err?: any) => void) => void
  ): (arg1: T1, arg2: T2) => Promise<void>;
  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>;
  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>;
  export function promisify<T1, T2, T3, T4, TResult>(
    fn: (
      arg1: T1,
      arg2: T2,
      arg3: T3,
      arg4: T4,
      callback: (err: any, result: TResult) => void
    ) => void
  ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>;
  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>;
  export function promisify<T1, T2, T3, T4, T5, TResult>(
    fn: (
      arg1: T1,
      arg2: T2,
      arg3: T3,
      arg4: T4,
      arg5: T5,
      callback: (err: any, result: TResult) => void
    ) => void
  ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>;
  export function promisify<T1, T2, T3, T4, T5>(
    fn: (
      arg1: T1,
      arg2: T2,
      arg3: T3,
      arg4: T4,
      arg5: T5,
      callback: (err?: any) => void
    ) => void
  ): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>;
  export function promisify(fn: Function): Function;
  export namespace promisify {
    /**
     * That can be used to declare custom promisified variants of functions.
     */
    const custom: unique symbol;
  }
  export interface EncodeIntoResult {
    /**
     * The read Unicode code units of input.
     */
    read: number;
    /**
     * The written UTF-8 bytes of output.
     */
    written: number;
  }
}
declare module "node:util" {
  export * from "util";
}
declare module "sys" {
  export * from "util";
}
declare module "node:sys" {
  export * from "util";
}