AsyncEventEmitter

Extends

EventEmitter

Type parameters

• T extends EventMap

Constructors

new AsyncEventEmitter()

new AsyncEventEmitter<T>(options?): AsyncEventEmitter<T>

Parameters

• options?: EventEmitterOptions

Returns

AsyncEventEmitter<T>

Inherited from

EventEmitter.constructor

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:133

Properties

beforeOrAfter

private beforeOrAfter: any

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:21

captureRejectionSymbol

static readonly captureRejectionSymbol: typeof captureRejectionSymbol

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

See how to write a custom rejection handler.

Since

v13.4.0, v12.16.0

Inherited from

EventEmitter.captureRejectionSymbol

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:430

captureRejections

static captureRejections: boolean

Value: boolean

Change the default captureRejections option on all new EventEmitter objects.

Since

v13.4.0, v12.16.0

Inherited from

EventEmitter.captureRejections

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:437

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'.

Since

v0.11.2

Inherited from

EventEmitter.defaultMaxListeners

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:476

errorMonitor

static readonly 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.

Since

v13.6.0, v12.17.0

Inherited from

EventEmitter.errorMonitor

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:423

Methods

`[captureRejectionSymbol]`()?

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

Type parameters

• K

Parameters

• error: Error

• event: string | symbol

• …args: AnyRest

Returns

void

Inherited from

EventEmitter.[captureRejectionSymbol]

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:135

addListener()

addListener<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Overrides

EventEmitter.addListener

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:23

after()

after<E>(event, target, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• target: T[E]

• listener: T[E]

Returns

this

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:20

before()

before<E>(event, target, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• target: T[E]

• listener: T[E]

Returns

this

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:19

emit()

emit<E>(event, …args): boolean

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• …args: Parameters<T[E]>

Returns

boolean

Overrides

EventEmitter.emit

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:16

eventNames()

eventNames(): keyof T & string[]

Returns

keyof T & string[]

Overrides

EventEmitter.eventNames

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:28

first()

first<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:18

getMaxListeners()

getMaxListeners(): number

Returns

number

Overrides

EventEmitter.getMaxListeners

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:31

listenerCount()

listenerCount(event): number

Parameters

• event: keyof T & string

Returns

number

Overrides

EventEmitter.listenerCount

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:30

listeners()

listeners<E>(event): T[E][]

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

Returns

T[E][]

Overrides

EventEmitter.listeners

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:29

off()

off<K>(eventName, listener): this

Alias for emitter.removeListener().

Type parameters

• K

Parameters

• eventName: string | symbol

• listener

Returns

this

Inherited from

EventEmitter.off

Since

v10.0.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:725

on()

on<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Overrides

EventEmitter.on

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:22

once()

once<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Overrides

EventEmitter.once

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:17

prependListener()

prependListener<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Overrides

EventEmitter.prependListener

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:24

prependOnceListener()

prependOnceListener<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Overrides

EventEmitter.prependOnceListener

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:25

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

• K

Parameters

• eventName: string | symbol

Returns

Function[]

Inherited from

EventEmitter.rawListeners

Since

v9.4.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:796

removeAllListeners()

removeAllListeners(event?): this

Parameters

• event?: keyof T & string

Returns

this

Overrides

EventEmitter.removeAllListeners

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:26

removeListener()

removeListener<E>(event, listener): this

Type parameters

• E extends string | number | symbol

Parameters

• event: E & string

• listener: T[E]

Returns

this

Overrides

EventEmitter.removeListener

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:27

setMaxListeners()

setMaxListeners(maxListeners): this

Parameters

• maxListeners: number

Returns

this

Overrides

EventEmitter.setMaxListeners

Source

node_modules/.pnpm/@ethereumjs+util@9.0.3/node_modules/@ethereumjs/util/dist/esm/asyncEventEmitter.d.ts:32

addAbortListener()

Experimental

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

• signal: AbortSignal

• resource

Returns

Disposable

Disposable that removes the abort listener.

Inherited from

EventEmitter.addAbortListener

Since

v20.5.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:415

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

• emitter: EventEmitter<DefaultEventMap> | EventTarget

• name: string | symbol

Returns

Function[]

Inherited from

EventEmitter.getEventListeners

Since

v15.2.0, v14.17.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:336

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

• emitter: EventEmitter<DefaultEventMap> | EventTarget

Returns

number

Inherited from

EventEmitter.getMaxListeners

Since

v19.9.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:365

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

• emitter: EventEmitter<DefaultEventMap>

The emitter to query

• eventName: string | symbol

The event name

Returns

number

Inherited from

EventEmitter.listenerCount

Since

v0.9.12

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:308

on()

on(emitter, eventName, options)

static on(emitter, eventName, options?): AsyncIterableIterator<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());

Parameters

• emitter: EventEmitter<DefaultEventMap>

• eventName: string | symbol

The name of the event being listened for

• options?: StaticEventEmitterOptions

Returns

AsyncIterableIterator<any>

An AsyncIterator that iterates eventName events emitted by the emitter

Inherited from

EventEmitter.on

Since

v13.6.0, v12.16.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:281

on(emitter, eventName, options)

static on(emitter, eventName, options?): AsyncIterableIterator<any>

Parameters

• emitter: EventTarget

• eventName: string

• options?: StaticEventEmitterOptions

Returns

AsyncIterableIterator<any>

Inherited from

EventEmitter.on

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:286

once()

once(emitter, eventName, options)

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

• emitter: EventEmitter<DefaultEventMap>

• eventName: string | symbol

• options?: Pick<StaticEventEmitterOptions, "signal">

Returns

Promise<any[]>

Inherited from

EventEmitter.once

Since

v11.13.0, v10.16.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:216

once(emitter, eventName, options)

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

Parameters

• emitter: EventTarget

• eventName: string

• options?: StaticEventEmitterOptions

Returns

Promise<any[]>

Inherited from

EventEmitter.once

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:221

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

• n?: number

A non-negative number. The maximum number of listeners per EventTarget event.

• …eventTargets?: (EventEmitter<DefaultEventMap> | EventTarget)[]

Returns

void

Inherited from

EventEmitter.setMaxListeners

Since

v15.4.0

Source

node_modules/.pnpm/@types+node@20.14.2/node_modules/@types/node/events.d.ts:380

AsyncEventEmitter

Extends

Type parameters

Constructors

new AsyncEventEmitter()

Parameters

Returns

Inherited from

Source

Properties

beforeOrAfter

Source

captureRejectionSymbol

Since

Inherited from

Source

captureRejections

Since

Inherited from

Source

defaultMaxListeners

Since

Inherited from

Source

errorMonitor

Since

Inherited from

Source

Methods

[captureRejectionSymbol]()?

Type parameters

Parameters

Returns

Inherited from

Source

addListener()

Type parameters

Parameters

Returns

Overrides

Source

after()

Type parameters

Parameters

Returns

Source

before()

Type parameters

Parameters

Returns

Source

emit()

Type parameters

Parameters

Returns

Overrides

Source

eventNames()

Returns

Overrides

Source

first()

Type parameters

Parameters

Returns

Source

getMaxListeners()

Returns

Overrides

Source

listenerCount()

Parameters

Returns

Overrides

Source

listeners()

Type parameters

Parameters

Returns

Overrides

`[captureRejectionSymbol]`()?