Icon LinkClass: FuelConnector

@fuel-ts/account .FuelConnector

FuelConnector

Wallet Connector is a interface that represents a Wallet Connector and all the methods that should be implemented to be compatible with the Fuel SDK.

Icon LinkHierarchy

• EventEmitter

  ↳ FuelConnector

  ↳↳ Fuel

Icon LinkConstructors

Icon Linkconstructor

• new FuelConnector(options?): FuelConnector

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.constructor

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:111

Icon LinkProperties

Icon Linkconnected

• connected: boolean = false

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:26 Icon Link

Icon Linkevents

• events: typeof FuelConnectorEventTypes = FuelConnectorEventTypes

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:28 Icon Link

Icon Linkinstalled

• installed: boolean = false

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:27 Icon Link

Icon Linkmetadata

• metadata: ConnectorMetadata

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:25 Icon Link

Icon Linkname

• name: string = ''

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:24 Icon Link

Icon LinkcaptureRejectionSymbol

▪ Static Readonly captureRejectionSymbol: typeof captureRejectionSymbol

Icon LinkInherited from

EventEmitter.captureRejectionSymbol

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:328

Icon LinkcaptureRejections

▪ Static captureRejections: boolean

Sets or gets the default captureRejection value for all emitters.

Icon LinkInherited from

EventEmitter.captureRejections

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:333

Icon LinkdefaultMaxListeners

▪ Static defaultMaxListeners: number

Icon LinkInherited from

EventEmitter.defaultMaxListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:334

Icon LinkerrorMonitor

▪ 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.

Icon LinkInherited from

EventEmitter.errorMonitor

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:327

Icon LinkMethods

Icon Linkaccounts

▸ accounts(): Promise<string[]>

Should return all the accounts authorized for the current connection.

Icon LinkReturns

Promise<string[]>

The accounts addresses strings

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:66 Icon Link

Icon LinkaddABI

▸ addABI(_contractId, _abi): Promise<boolean>

Should add the ABI to the connector and return true if the ABI was added successfully.

Icon LinkParameters

Icon LinkReturns

Promise<boolean>

Return true if the ABI was added successfully.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:237 Icon Link

Icon LinkaddAsset

▸ addAsset(_asset): Promise<boolean>

Should add the the asset metadata to the connector and return true if the asset was added successfully.

If the asset already exists it should throw an error.

assets

Throws

Error if the asset already exists

Icon LinkParameters

Icon LinkReturns

Promise<boolean>

True if the asset was added successfully

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:175 Icon Link

Icon LinkaddAssets

▸ addAssets(_assets): Promise<boolean>

Should add the the assets metadata to the connector and return true if the asset was added successfully.

If the asset already exists it should throw an error.

assets

Throws

Error if the asset already exists

Icon LinkParameters

Icon LinkReturns

Promise<boolean>

True if the asset was added successfully

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:160 Icon Link

Icon LinkaddListener

▸ addListener(eventName, listener): FuelConnector

Alias for emitter.on(eventName, listener).

Since

v0.1.26

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.addListener

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:354

Icon LinkaddNetwork

▸ addNetwork(_networkUrl): Promise<boolean>

Should start the add network process and return true if the network was added successfully.

networks

Throws

Error if the network already exists

Icon LinkParameters

Icon LinkReturns

Promise<boolean>

Return true if the network was added successfully

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:196 Icon Link

Icon Linkassets

▸ assets(): Promise<Asset []>

Should return all the assets added to the connector. If a connection is already established.

Icon LinkReturns

Promise<Asset []>

Array of assets metadata from the connector vinculated to the all accounts from a specific Wallet.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:184 Icon Link

Icon Linkconnect

▸ connect(): Promise<boolean>

Should start the connection process and return true if the account authorize the connection.

and return false if the user reject the connection.

accounts

Icon LinkReturns

Promise<boolean>

boolean - connection status.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:79 Icon Link

Icon LinkcurrentAccount

▸ currentAccount(): Promise<null | string>

Should return the current account selected inside the connector, if the account is authorized for the connection.

If the account is not authorized it should return null.

Icon LinkReturns

Promise<null | string>

The current account selected otherwise null.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:145 Icon Link

Icon LinkcurrentNetwork

▸ currentNetwork(): Promise<Network >

Should return the current network selected inside the connector. Even if the connection is not established.

Icon LinkReturns

Promise<Network >

Return the current network selected inside the connector.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:226 Icon Link

Icon Linkdisconnect

▸ disconnect(): Promise<boolean>

Should disconnect the current connection and return false if the disconnection was successful.

assets connection

Icon LinkReturns

Promise<boolean>

The connection status.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:90 Icon Link

Icon Linkemit

▸ emit(eventName, ...args): boolean

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

Returns true if the event had listeners, false otherwise.

const EventEmitter = require('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

Since

v0.1.26

Icon LinkParameters

Icon LinkReturns

boolean

Icon LinkInherited from

EventEmitter.emit

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:610

Icon LinkeventNames

▸ 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.

const EventEmitter = require('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) ]

Since

v6.0.0

Icon LinkReturns

(string | symbol)[]

Icon LinkInherited from

EventEmitter.eventNames

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:669

Icon LinkgetABI

▸ getABI(_id): Promise<null | JsonAbi>

Should return the ABI from the connector vinculated to the all accounts from a specific Wallet.

Icon LinkParameters

Icon LinkReturns

Promise<null | JsonAbi>

The ABI if it exists, otherwise return null.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:247 Icon Link

Icon LinkgetMaxListeners

▸ getMaxListeners(): number

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

Since

v1.0.0

Icon LinkReturns

number

Icon LinkInherited from

EventEmitter.getMaxListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:526

Icon LinkhasABI

▸ hasABI(_id): Promise<boolean>

Should return true if the abi exists in the connector vinculated to the all accounts from a specific Wallet.

Icon LinkParameters

Icon LinkReturns

Promise<boolean>

Returns true if the abi exists or false if not.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:257 Icon Link

Icon LinkisConnected

▸ isConnected(): Promise<boolean>

Should return true if the connector is connected to any of the accounts available.

Icon LinkReturns

Promise<boolean>

The connection status.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:56 Icon Link

Icon LinklistenerCount

▸ listenerCount(eventName): number

Returns the number of listeners listening to the event named eventName.

Since

v3.2.0

Icon LinkParameters

Icon LinkReturns

number

Icon LinkInherited from

EventEmitter.listenerCount

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:616

Icon Linklisteners

▸ listeners(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] ]

Since

v0.1.26

Icon LinkParameters

Icon LinkReturns

Function[]

Icon LinkInherited from

EventEmitter.listeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:539

Icon Linknetworks

▸ networks(): Promise<Network []>

Should return all the networks available from the connector. If the connection is already established.

Icon LinkReturns

Promise<Network []>

Return all the networks added to the connector.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:217 Icon Link

Icon Linkoff

▸ off(eventName, listener): FuelConnector

Alias for emitter.removeListener().

Since

v10.0.0

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.off

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:499

Icon Linkon

▸ on<E, D>(eventName, listener): FuelConnector

Event listener for the connector.

Icon LinkType parameters

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkOverrides

EventEmitter.on

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:267 Icon Link

Icon Linkonce

▸ once(eventName, listener): FuelConnector

Adds a one-timelistener 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. Theemitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Since

v0.3.0

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.once

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:414

Icon Linkping

▸ ping(): Promise<boolean>

Should return true if the connector is loaded in less then one second.

Icon LinkReturns

Promise<boolean>

Always true.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:36 Icon Link

Icon LinkprependListener

▸ prependListener(eventName, listener): FuelConnector

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 eventNameand 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.

Since

v6.0.0

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.prependListener

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:634

Icon LinkprependOnceListener

▸ prependOnceListener(eventName, listener): FuelConnector

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.

Since

v6.0.0

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.prependOnceListener

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:650

Icon LinkrawListeners

▸ rawListeners(eventName): Function[]

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

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');

Since

v9.4.0

Icon LinkParameters

Icon LinkReturns

Function[]

Icon LinkInherited from

EventEmitter.rawListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:569

Icon LinkremoveAllListeners

▸ removeAllListeners(event?): FuelConnector

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.

Since

v0.1.26

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.removeAllListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:510

Icon LinkremoveListener

▸ removeListener(eventName, listener): FuelConnector

Removes the specified listener from the listener array for the event namedeventName.

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 anyremoveListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them fromemit() in progress. Subsequent events behave as expected.

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:

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.

Since

v0.1.26

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.removeListener

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:494

Icon LinkselectNetwork

▸ selectNetwork(_network): Promise<boolean>

Should start the select network process and return true if the network has change successfully.

networks

Throws

Error if the network already exists

Icon LinkParameters

Icon LinkReturns

Promise<boolean>

Return true if the network was added successfully

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:208 Icon Link

Icon LinksendTransaction

▸ sendTransaction(_address, _transaction): Promise<string>

Should start the send transaction process and return the transaction id submitted to the network.

If the network is not available for the connection it should throw an error to avoid the transaction to be sent to the wrong network and lost.

Icon LinkParameters

Icon LinkReturns

Promise<string>

The transaction id

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:133 Icon Link

Icon LinksetMaxListeners

▸ setMaxListeners(n): FuelConnector

By default EventEmitters 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 toInfinity (or 0) to indicate an unlimited number of listeners.

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

Since

v0.3.5

Icon LinkParameters

Icon LinkReturns

FuelConnector

Icon LinkInherited from

EventEmitter.setMaxListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:520

Icon LinksignMessage

▸ signMessage(_address, _message): Promise<string>

Should start the sign message process and return the signed message.

Icon LinkParameters

Icon LinkReturns

Promise<string>

Message signature

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:103 Icon Link

Icon LinksignTransaction

▸ signTransaction(_address, _transaction): Promise<string>

Should start the sign transaction process and return the signed transaction.

Icon LinkParameters

Icon LinkReturns

Promise<string>

Transaction signature

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:116 Icon Link

Icon Linkversion

▸ version(): Promise<Version >

Should return the current version of the connector and the network version that is compatible.

Icon LinkReturns

Promise<Version >

boolean - connection status.

Icon LinkDefined in

packages/account/src/connectors/fuel-connector.ts:46 Icon Link

Icon LinkgetEventListeners

▸ 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.

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

Since

v15.2.0, v14.17.0

Icon LinkParameters

Icon LinkReturns

Function[]

Icon LinkInherited from

EventEmitter.getEventListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:299

Icon LinklistenerCount

▸ listenerCount(emitter, eventName): number

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

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

Since

v0.9.12

Deprecated

Since v3.2.0 - Use listenerCount instead.

Icon LinkParameters

Icon LinkReturns

number

Icon LinkInherited from

EventEmitter.listenerCount

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:271

Icon Linkon

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

const { on, EventEmitter } = require('events');
 
(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')) {
    // 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:

const { on, EventEmitter } = require('events');
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());

Since

v13.6.0, v12.16.0

Icon LinkParameters

Icon LinkReturns

AsyncIterableIterator<any>

that iterates eventName events emitted by the emitter

Icon LinkInherited from

EventEmitter.on

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:254

Icon Linkonce

▸ 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 Icon Link interface, which has no special'error' event semantics and does not listen to the 'error' event.

const { once, EventEmitter } = require('events');
 
async function run() {
  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.log('error happened', err);
  }
}
 
run();

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:

const { EventEmitter, once } = require('events');
 
const ee = new EventEmitter();
 
once(ee, 'error')
  .then(([err]) => console.log('ok', err.message))
  .catch((err) => console.log('error', err.message));
 
ee.emit('error', new Error('boom'));
 
// Prints: ok boom

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

const { EventEmitter, once } = require('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!

Since

v11.13.0, v10.16.0

Icon LinkParameters

Icon LinkReturns

Promise<any[]>

Icon LinkInherited from

EventEmitter.once

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:194

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

Icon LinkParameters

Icon LinkReturns

Promise<any[]>

Icon LinkInherited from

EventEmitter.once

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:195

Icon LinksetMaxListeners

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

const {
  setMaxListeners,
  EventEmitter
} = require('events');
 
const target = new EventTarget();
const emitter = new EventEmitter();
 
setMaxListeners(5, target, emitter);

Since

v15.4.0

Icon LinkParameters

Icon LinkReturns

void

Icon LinkInherited from

EventEmitter.setMaxListeners

Icon LinkDefined in

node_modules/.pnpm/@types+node@18.15.3/node_modules/@types/node/events.d.ts:317