Class: REST

Extends: BaseClient

Main REST client with lazy-loaded API resources

Constructors

Constructor

new REST(options?): REST

Parameters

Name	Type	Description
options?	BaseClientOptions

Returns

REST

Overrides

BaseClient.constructor

Properties

captureRejections

static captureRejections: boolean

Value: boolean

Change the default captureRejections option on all new EventEmitter objects.

Inherited from

BaseClient.captureRejections

---

captureRejectionSymbol

readonly static captureRejectionSymbol: typeof captureRejectionSymbol

Value: Symbol.for('nodejs.rejection')

See how to write a custom rejection handler.

Inherited from

BaseClient.captureRejectionSymbol

---

defaultMaxListeners

static defaultMaxListeners: number

By default, a maximum of 10 listeners can be registered for any single event. This limit can be changed for individual EventEmitter instances using the emitter.setMaxListeners(n) method. To change the default for allEventEmitter instances, the events.defaultMaxListeners property can be used. If this value is not a positive number, a RangeError is thrown.

Take caution when setting the events.defaultMaxListeners because the change affects all EventEmitter instances, including those created before the change is made. However, calling emitter.setMaxListeners(n) still has precedence over events.defaultMaxListeners.

This is not a hard limit. The EventEmitter instance will allow more listeners to be added but will output a trace warning to stderr indicating that a "possible EventEmitter memory leak" has been detected. For any single EventEmitter, the emitter.getMaxListeners() and emitter.setMaxListeners() methods can be used to temporarily avoid this warning:

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.setMaxListeners(emitter.getMaxListeners() + 1);
emitter.once('event', () => {
  // do stuff
  emitter.setMaxListeners(Math.max(emitter.getMaxListeners() - 1, 0));
});

The --trace-warnings command-line flag can be used to display the stack trace for such warnings.

The emitted warning can be inspected with process.on('warning') and will have the additional emitter, type, and count properties, referring to the event emitter instance, the event's name and the number of attached listeners, respectively. Its name property is set to 'MaxListenersExceededWarning'.

Inherited from

BaseClient.defaultMaxListeners

---

errorMonitor

readonly static errorMonitor: typeof errorMonitor

This symbol shall be used to install a listener for only monitoring 'error' events. Listeners installed using this symbol are called before the regular 'error' listeners are called.

Installing a listener using this symbol does not change the behavior once an 'error' event is emitted. Therefore, the process will still crash if no regular 'error' listener is installed.

Inherited from

BaseClient.errorMonitor

Accessors

account

Get Signature

get account(): AccountResource

Get account resource

Returns

AccountResource

AccountResource instance

---

apps

Get Signature

get apps(): AppResource

Get apps resource

Returns

AppResource

AppResource instance

---

dialogs

Get Signature

get dialogs(): DialogResource

Get dialogs resource

Returns

DialogResource

DialogResource instance

---

files

Get Signature

get files(): FilesResource

Get files resource

Returns

FilesResource

FilesResource instance

---

musebase

Get Signature

get musebase(): MusebaseResource

Get musebase resource

Returns

MusebaseResource

MusebaseResource instance

---

photos

Get Signature

get photos(): PhotosResource

Get photos resource

Returns

PhotosResource

PhotosResource instance

---

posts

Get Signature

get posts(): PostResource

Get posts resource

Returns

PostResource

PostResource instance

---

search

Get Signature

get search(): SearchResource

Get search resource

Returns

SearchResource

SearchResource instance

---

shop

Get Signature

get shop(): ShopResource

Get shop resource

Returns

ShopResource

ShopResource instance

---

users

Get Signature

get users(): UserResource

Get users resource

Returns

UserResource

UserResource instance

---

video

Get Signature

get video(): VideoResource

Get video resource

Returns

VideoResource

VideoResource instance

Methods

[captureRejectionSymbol]()?

optional [captureRejectionSymbol]<K>(error, event, ...args): void

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
error	Error
event	string | symbol
args	AnyRest

Returns

void

Inherited from

BaseClient.[captureRejectionSymbol]

---

addListener()

addListener<K>(eventName, listener): this

Alias for emitter.on(eventName, listener).

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol
listener	(...args) => void

Returns

this

Inherited from

BaseClient.addListener

---

batch()

batch(): BatchRequest

Create a new batch request for parallel API calls

Returns

BatchRequest

BatchRequest instance

Example

const results = await rest.batch()
  .add('user', rest.users.me())
  .add('posts', rest.posts.get('@me', {}))
  .execute();

console.log(results.user);  // User object
console.log(results.posts); // Posts array

---

cancelAllRequests()

cancelAllRequests(): void

Cancel all pending requests

Returns

void

Inherited from

BaseClient.cancelAllRequests

---

cancelRequest(endpoint): void

`

Cancel a specific request by endpoint

Parameters

Name	Type	Description
endpoint	string	API endpoint to cancel

Returns

void

Inherited from

BaseClient.cancelRequest

---

clearCache()

clearCache(): void

Clear user cache

Returns

void

Inherited from

BaseClient.clearCache

---

delete()

delete<T>(endpoint, config?): Promise<T>

Perform DELETE request

Type Parameters

Name	Type	Description
T	any

Parameters

Name	Type	Description
endpoint	string	API endpoint
config?	RequestConfig	Request configuration

Returns

Promise<T>

Promise resolving to response data

Inherited from

BaseClient.delete

---

emit()

emit<K>(eventName, ...args): boolean

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol
args	AnyRest

Returns

boolean

Inherited from

BaseClient.emit

---

eventNames()

eventNames(): (string | symbol)[]

Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

Returns

(string | symbol)[]

Inherited from

BaseClient.eventNames

---

get()

get<T>(endpoint, queryParams, config?): Promise<T>

Perform GET request

Type Parameters

Name	Type	Description
T	any

Parameters

Name	Type	Description
endpoint	string	API endpoint
queryParams?	Record<string, unknown>	Query parameters
config?	RequestConfig	Request configuration

Returns

Promise<T>

Promise resolving to response data

Inherited from

BaseClient.get

---

getCachedUser()

getCachedUser(): Promise<null | CachedUser>

Get cached user data

Returns

Promise<null | CachedUser>

Promise resolving to cached user or null

Inherited from

BaseClient.getCachedUser

---

getMaxListeners()

getMaxListeners(): number

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.

Returns

number

Inherited from

BaseClient.getMaxListeners

---

getRateLimitStatus()

getRateLimitStatus(): null | { canMakeRequest: boolean; resetTime: number; }

Get current rate limit status

Returns

null | { canMakeRequest: boolean; resetTime: number; }

Rate limit status or null if not configured

Inherited from

BaseClient.getRateLimitStatus

---

listenerCount()

listenerCount<K>(eventName, listener?): number

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol	The name of the event being listened for
listener?	Function	The event handler function

Returns

number

Inherited from

BaseClient.listenerCount

---

listeners()

listeners<K>(eventName): Function[]

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol

Returns

Function[]

Inherited from

BaseClient.listeners

---

off()

off<K>(eventName, listener): this

Alias for emitter.removeListener().

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol
listener	(...args) => void

Returns

this

Inherited from

BaseClient.off

---

on()

on<K>(eventName, listener): this

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol	The name of the event.
listener	(...args) => void	The callback function

Returns

this

Inherited from

BaseClient.on

---

once()

once<K>(eventName, listener): this

Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol	The name of the event.
listener	(...args) => void	The callback function

Returns

this

Inherited from

BaseClient.once

---

patch()

patch<T>(endpoint, data, config?): Promise<T>

Perform PATCH request

Type Parameters

Name	Type	Description
T	any

Parameters

Name	Type	Description
endpoint	string	API endpoint
data?	unknown	Request body data
config?	RequestConfig	Request configuration

Returns

Promise<T>

Promise resolving to response data

Inherited from

BaseClient.patch

---

post()

post<T>(endpoint, data, config?): Promise<T>

Perform POST request

Type Parameters

Name	Type	Description
T	any

Parameters

Name	Type	Description
endpoint	string	API endpoint
data?	unknown	Request body data
config?	RequestConfig	Request configuration

Returns

Promise<T>

Promise resolving to response data

Inherited from

BaseClient.post

---

prependListener()

prependListener<K>(eventName, listener): this

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol	The name of the event.
listener	(...args) => void	The callback function

Returns

this

Inherited from

BaseClient.prependListener

---

prependOnceListener()

prependOnceListener<K>(eventName, listener): this

Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol	The name of the event.
listener	(...args) => void	The callback function

Returns

this

Inherited from

BaseClient.prependOnceListener

---

put()

put<T>(endpoint, data, config?): Promise<T>

Perform PUT request

Type Parameters

Name	Type	Description
T	any

Parameters

Name	Type	Description
endpoint	string	API endpoint
data?	unknown	Request body data
config?	RequestConfig	Request configuration

Returns

Promise<T>

Promise resolving to response data

Inherited from

BaseClient.put

---

rawListeners()

rawListeners<K>(eventName): Function[]

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol

Returns

Function[]

Inherited from

BaseClient.rawListeners

---

removeAllListeners(eventName?): this v0.1.26

Removes all listeners, or those of the specified `eventName`.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

Name	Type	Description
eventName?	string | symbol

Returns

this

Inherited from

BaseClient.removeAllListeners

---

removeListener()

removeListener<K>(eventName, listener): this

Removes the specified listener from the listener array for the event named eventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them fromemit() in progress. Subsequent events behave as expected.

import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indices of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

import { EventEmitter } from 'node:events';
const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Name	Type	Description
K	any

Parameters

Name	Type	Description
eventName	string | symbol
listener	(...args) => void

Returns

this

Inherited from

BaseClient.removeListener

---

resolveUser(user): Promise<string | number>

`

Resolve user identifier

Parameters

Name	Type	Description
user	string | number	User identifier (string, number, or @me)

Returns

Promise<string | number>

Promise resolving to resolved user identifier

Inherited from

BaseClient.resolveUser

---

setCachedUser(user): void

`

Set cached user data

Parameters

Name	Type	Description
user	Omit<CachedUser, "timestamp">	User data to cache

Returns

void

Inherited from

BaseClient.setCachedUser

---

setMaxListeners(n): this v0.3.5

By default `EventEmitter`s will print a warning if more than `10` listeners are

added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

Name	Type	Description
n	number

Returns

this

Inherited from

BaseClient.setMaxListeners

---

setRateLimit(config): void

`

Set rate limiting configuration

Parameters

Name	Type	Description
config	RateLimitConfig	Rate limit configuration

Returns

void

Inherited from

BaseClient.setRateLimit

---

setToken(token): this

`

Set authentication token

Parameters

Name	Type	Description
token	null | string	Authentication token or null to remove

Returns

this *? This instance for chaining

Inherited from

BaseClient.setToken

---

uploadFile()

uploadFile<T>(endpoint, formData, config?): Promise<T>

Upload file using multipart/form-data

Type Parameters

Name	Type	Description
T	any

Parameters

Name	Type	Description
endpoint	string	API endpoint
formData	FormData	Form data containing file
config?	RequestConfig	Request configuration

Returns

Promise<T>

Promise resolving to response data

Inherited from

BaseClient.uploadFile

---

addAbortListener()

static addAbortListener(signal, resource): Disposable

Listens once to the abort event on the provided signal.

Listening to the abort event on abort signals is unsafe and may lead to resource leaks since another third party with the signal can call e.stopImmediatePropagation(). Unfortunately Node.js cannot change this since it would violate the web standard. Additionally, the original API makes it easy to forget to remove listeners.

This API allows safely using AbortSignals in Node.js APIs by solving these two issues by listening to the event such that stopImmediatePropagation does not prevent the listener from running.

Returns a disposable so that it may be unsubscribed from more easily.

import { addAbortListener } from 'node:events';

function example(signal) {
  let disposable;
  try {
    signal.addEventListener('abort', (e) => e.stopImmediatePropagation());
    disposable = addAbortListener(signal, (e) => {
      // Do something when signal is aborted.
    });
  } finally {
    disposable?.[Symbol.dispose]();
  }
}

Parameters

Name	Type	Description
signal	AbortSignal
resource	(event) => void

Returns

Disposable *? Disposable that removes the abort listener.

Inherited from

BaseClient.addAbortListener

---

getEventListeners()

static getEventListeners(emitter, name): Function[]

Returns a copy of the array of listeners for the event named eventName.

For EventEmitters this behaves exactly the same as calling .listeners on the emitter.

For EventTargets this is the only way to get the event listeners for the event target. This is useful for debugging and diagnostic purposes.

import { getEventListeners, EventEmitter } from 'node:events';

{
  const ee = new EventEmitter();
  const listener = () => console.log('Events are fun');
  ee.on('foo', listener);
  console.log(getEventListeners(ee, 'foo')); // [ [Function: listener] ]
}
{
  const et = new EventTarget();
  const listener = () => console.log('Events are fun');
  et.addEventListener('foo', listener);
  console.log(getEventListeners(et, 'foo')); // [ [Function: listener] ]
}

Parameters

Name	Type	Description
emitter	EventTarget | EventEmitter<DefaultEventMap>
name	string | symbol

Returns

Function[]

Inherited from

BaseClient.getEventListeners

---

getMaxListeners()

static getMaxListeners(emitter): number

Returns the currently set max amount of listeners.

For EventEmitters this behaves exactly the same as calling .getMaxListeners on the emitter.

For EventTargets this is the only way to get the max event listeners for the event target. If the number of event handlers on a single EventTarget exceeds the max set, the EventTarget will print a warning.

import { getMaxListeners, setMaxListeners, EventEmitter } from 'node:events';

{
  const ee = new EventEmitter();
  console.log(getMaxListeners(ee)); // 10
  setMaxListeners(11, ee);
  console.log(getMaxListeners(ee)); // 11
}
{
  const et = new EventTarget();
  console.log(getMaxListeners(et)); // 10
  setMaxListeners(11, et);
  console.log(getMaxListeners(et)); // 11
}

Parameters

Name	Type	Description
emitter	EventTarget | EventEmitter<DefaultEventMap>

Returns

number

Inherited from

BaseClient.getMaxListeners

---

listenerCount()

static listenerCount(emitter, eventName): number

A class method that returns the number of listeners for the given eventName registered on the given emitter.

import { EventEmitter, listenerCount } from 'node:events';

const myEmitter = new EventEmitter();
myEmitter.on('event', () => {});
myEmitter.on('event', () => {});
console.log(listenerCount(myEmitter, 'event'));
// Prints: 2

Parameters

Name	Type	Description
emitter	EventEmitter	The emitter to query
eventName	string | symbol	The event name

Returns

number

Deprecated

Since v3.2.0 - Use listenerCount instead.

Inherited from

BaseClient.listenerCount

---

on()

Call Signature

static on(emitter, eventName, options?): AsyncIterator<any[]>

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
});

for await (const event of on(ee, 'foo')) {
  // The execution of this inner block is synchronous and it
  // processes one event at a time (even with await). Do not use
  // if concurrent execution is required.
  console.log(event); // prints ['bar'] [42]
}
// Unreachable here

Returns an AsyncIterator that iterates eventName events. It will throw if the EventEmitter emits 'error'. It removes all listeners when exiting the loop. The value returned by each iteration is an array composed of the emitted event arguments.

An AbortSignal can be used to cancel waiting on events:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ac = new AbortController();

(async () => {
  const ee = new EventEmitter();

  // Emit later on
  process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
  });

  for await (const event of on(ee, 'foo', { signal: ac.signal })) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
  }
  // Unreachable here
})();

process.nextTick(() => ac.abort());

Use the close option to specify an array of event names that will end the iteration:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
  ee.emit('close');
});

for await (const event of on(ee, 'foo', { close: ['close'] })) {
  console.log(event); // prints ['bar'] [42]
}
// the loop will exit after 'close' is emitted
console.log('done'); // prints 'done'

Parameters

Name	Type	Description
emitter	EventEmitter
eventName	string | symbol
options?	StaticEventEmitterIteratorOptions

Returns

AsyncIterator<any[]>

An AsyncIterator that iterates eventName events emitted by the emitter

Inherited from

BaseClient.on

Call Signature

static on(emitter, eventName, options?): AsyncIterator<any[]>

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
});

for await (const event of on(ee, 'foo')) {
  // The execution of this inner block is synchronous and it
  // processes one event at a time (even with await). Do not use
  // if concurrent execution is required.
  console.log(event); // prints ['bar'] [42]
}
// Unreachable here

Returns an AsyncIterator that iterates eventName events. It will throw if the EventEmitter emits 'error'. It removes all listeners when exiting the loop. The value returned by each iteration is an array composed of the emitted event arguments.

An AbortSignal can be used to cancel waiting on events:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ac = new AbortController();

(async () => {
  const ee = new EventEmitter();

  // Emit later on
  process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
  });

  for await (const event of on(ee, 'foo', { signal: ac.signal })) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
  }
  // Unreachable here
})();

process.nextTick(() => ac.abort());

Use the close option to specify an array of event names that will end the iteration:

import { on, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

// Emit later on
process.nextTick(() => {
  ee.emit('foo', 'bar');
  ee.emit('foo', 42);
  ee.emit('close');
});

for await (const event of on(ee, 'foo', { close: ['close'] })) {
  console.log(event); // prints ['bar'] [42]
}
// the loop will exit after 'close' is emitted
console.log('done'); // prints 'done'

Parameters

Name	Type	Description
emitter	EventTarget
eventName	string
options?	StaticEventEmitterIteratorOptions

Returns

AsyncIterator<any[]>

An AsyncIterator that iterates eventName events emitted by the emitter

Inherited from

BaseClient.on

---

once()

Call Signature

static once(emitter, eventName, options?): Promise<any[]>

Creates a Promise that is fulfilled when the EventEmitter emits the given event or that is rejected if the EventEmitter emits 'error' while waiting. The Promise will resolve with an array of all the arguments emitted to the given event.

This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event semantics and does not listen to the 'error' event.

import { once, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

process.nextTick(() => {
  ee.emit('myevent', 42);
});

const [value] = await once(ee, 'myevent');
console.log(value);

const err = new Error('kaboom');
process.nextTick(() => {
  ee.emit('error', err);
});

try {
  await once(ee, 'myevent');
} catch (err) {
  console.error('error happened', err);
}

The special handling of the 'error' event is only used when events.once() is used to wait for another event. If events.once() is used to wait for the 'error' event itself, then it is treated as any other kind of event without special handling:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();

once(ee, 'error')
  .then(([err]) => console.log('ok', err.message))
  .catch((err) => console.error('error', err.message));

ee.emit('error', new Error('boom'));

// Prints: ok boom

An AbortSignal can be used to cancel waiting for the event:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();
const ac = new AbortController();

async function foo(emitter, event, signal) {
  try {
    await once(emitter, event, { signal });
    console.log('event emitted!');
  } catch (error) {
    if (error.name === 'AbortError') {
      console.error('Waiting for the event was canceled!');
    } else {
      console.error('There was an error', error.message);
    }
  }
}

foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!

Parameters

Name	Type	Description
emitter	EventEmitter
eventName	string | symbol
options?	StaticEventEmitterOptions

Returns

Promise<any[]>

Inherited from

BaseClient.once

Call Signature

static once(emitter, eventName, options?): Promise<any[]>

Creates a Promise that is fulfilled when the EventEmitter emits the given event or that is rejected if the EventEmitter emits 'error' while waiting. The Promise will resolve with an array of all the arguments emitted to the given event.

This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event semantics and does not listen to the 'error' event.

import { once, EventEmitter } from 'node:events';
import process from 'node:process';

const ee = new EventEmitter();

process.nextTick(() => {
  ee.emit('myevent', 42);
});

const [value] = await once(ee, 'myevent');
console.log(value);

const err = new Error('kaboom');
process.nextTick(() => {
  ee.emit('error', err);
});

try {
  await once(ee, 'myevent');
} catch (err) {
  console.error('error happened', err);
}

The special handling of the 'error' event is only used when events.once() is used to wait for another event. If events.once() is used to wait for the 'error' event itself, then it is treated as any other kind of event without special handling:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();

once(ee, 'error')
  .then(([err]) => console.log('ok', err.message))
  .catch((err) => console.error('error', err.message));

ee.emit('error', new Error('boom'));

// Prints: ok boom

An AbortSignal can be used to cancel waiting for the event:

import { EventEmitter, once } from 'node:events';

const ee = new EventEmitter();
const ac = new AbortController();

async function foo(emitter, event, signal) {
  try {
    await once(emitter, event, { signal });
    console.log('event emitted!');
  } catch (error) {
    if (error.name === 'AbortError') {
      console.error('Waiting for the event was canceled!');
    } else {
      console.error('There was an error', error.message);
    }
  }
}

foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!

Parameters

Name	Type	Description
emitter	EventTarget
eventName	string
options?	StaticEventEmitterOptions

Returns

Promise<any[]>

Inherited from

BaseClient.once

---

setMaxListeners()

static setMaxListeners(n?, ...eventTargets?): void

import { setMaxListeners, EventEmitter } from 'node:events';

const target = new EventTarget();
const emitter = new EventEmitter();

setMaxListeners(5, target, emitter);

Parameters

Name	Type	Description
n?	number	A non-negative number. The maximum number of listeners per EventTarget event.
eventTargets	(EventTarget | EventEmitter<DefaultEventMap>)[]	Zero or more {EventTarget} or {EventEmitter} instances. If none are specified, n is set as the default max for all newly created {EventTarget} and
objects.

Returns

void

Inherited from

BaseClient.setMaxListeners