Ruvyrias
ruvyrias / Ruvyrias
Class: Ruvyrias
Defined in: src/Ruvyrias.ts:308
Represents the main Ruvyrias instance, coordinating interactions with nodes and players.
Extends
EventEmitter
Constructors
Constructor
new Ruvyrias(
client
,nodes
,options
):Ruvyrias
Defined in: src/Ruvyrias.ts:333
This is the main class of Ruvyrias
Parameters
client
any
VoiceClient for Ruvyrias library to use to connect to lavalink node server (discord.js, eris, oceanic)
nodes
Node
options
Omit
<RuvyriasOptions
, "clientVersion"
| "isInitialized"
| "resumeTimeout"
>
RuvyriasOptions
Returns
Ruvyrias
Ruvyrias
Properties
client
readonly
client:any
Defined in: src/Ruvyrias.ts:319
nodesMap
nodesMap:
Map
<string
,Node
>
Defined in: src/Ruvyrias.ts:322
options
options:
RuvyriasOptions
Defined in: src/Ruvyrias.ts:321
players
players:
Map
<string
,Player
>
Defined in: src/Ruvyrias.ts:323
send
send:
null
|Function
Defined in: src/Ruvyrias.ts:324
captureRejections
static
captureRejections:boolean
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:458
Value: boolean
Change the default captureRejections
option on all new EventEmitter
objects.
Since
v13.4.0, v12.16.0
captureRejectionSymbol
readonly
static
captureRejectionSymbol: typeofcaptureRejectionSymbol
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:451
Value: Symbol.for('nodejs.rejection')
See how to write a custom rejection handler
.
Since
v13.4.0, v12.16.0
defaultMaxListeners
static
defaultMaxListeners:number
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:497
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
errorMonitor
readonly
static
errorMonitor: typeoferrorMonitor
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:444
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
Accessors
leastUsedNodes
Get Signature
get leastUsedNodes():
Node
[]
Defined in: src/Ruvyrias.ts:587
Gets an array of least used nodes from the Ruvyrias instance.
Returns
Node
[]
An array of least used nodes.
Methods
[captureRejectionSymbol]()?
optional
[captureRejectionSymbol]<K
>(error
,event
, ...args
):void
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:136
Type Parameters
K
K
Parameters
error
Error
event
string
| symbol
args
...AnyRest
Returns
void
addListener()
addListener<
K
>(eventName
,listener
):this
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:596
Alias for emitter.on(eventName, listener)
.
Type Parameters
K
K
Parameters
eventName
string
| symbol
listener
(...args
) => void
Returns
this
Since
v0.1.26
createConnection()
createConnection(
options
):Player
Defined in: src/Ruvyrias.ts:512
Creates a player connection for the specified guild using the provided options.
Parameters
options
Options for creating the player connection.
Returns
The created or existing Player instance for the specified guild.
createNode()
createNode(
options
):Promise
<Node
>
Defined in: src/Ruvyrias.ts:437
Adds a node to the Ruvyrias instance.
Parameters
options
NodeGroup containing node configuration.
Returns
Promise
<Node
>
- The created Node instance.
decodeTrack()
decodeTrack(
track
,node?
):Promise
<TrackData
>
Defined in: src/Ruvyrias.ts:621
Decode a track from Ruvyrias instance.
Parameters
track
string
The encoded track.
node?
The node to decode the track on. If not provided, the least used node will be used.
Returns
Promise
<TrackData
>
A promise that resolves to the decoded track.
decodeTracks()
decodeTracks(
tracks
,node?
):Promise
<Track
[]>
Defined in: src/Ruvyrias.ts:633
Decode tracks from Ruvyrias instance.
Parameters
tracks
string
[]
The encoded strings.
node?
The node to decode the tracks on. If not provided, the least used node will be used.
Returns
Promise
<Track
[]>
A promise that resolves to an array of decoded tracks.
destroyNode()
destroyNode(
identifier
):Promise
<boolean
>
Defined in: src/Ruvyrias.ts:451
Removes a node from the Ruvyrias instance.
Parameters
identifier
string
Node name.
Returns
Promise
<boolean
>
Whether the node was successfully removed.
destroyPlayer()
destroyPlayer(
guildId
):null
|boolean
Defined in: src/Ruvyrias.ts:562
Destroys the player instance for the specified guild using the provided guild ID.
Parameters
guildId
string
The ID of the guild associated with the player instance.
Returns
null
| boolean
A Promise that resolves with a boolean indicating success or null if no specific value is needed.
emit()
emit<
K
>(event
, ...args
):boolean
Defined in: src/Ruvyrias.ts:311
Type Parameters
K
K
extends keyof RuvyriasEvents
Parameters
event
K
args
...Parameters
<RuvyriasEvents
[K
]>
Returns
boolean
eventNames()
eventNames(): (
string
|symbol
)[]
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:921
Returns an array listing the events for which the emitter has registered
listeners. The values in the array are strings or Symbol
s.
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
)[]
Since
v6.0.0
get()
get(
guildId
):null
|Player
Defined in: src/Ruvyrias.ts:686
Get a player from Ruvyrias instance.
Parameters
guildId
string
Guild ID.
Returns
null
| Player
The player instance for the specified guild or undefined in case of nothing.
getLavalinkInfo()
getLavalinkInfo(
name
):Promise
<NodeInfoResponse
>
Defined in: src/Ruvyrias.ts:644
Get lavalink info from Ruvyrias instance
Parameters
name
string
The name of the node
Returns
Promise
<NodeInfoResponse
>
Useful information about the node.
getLavalinkStatus()
getLavalinkStatus(
name
):Promise
<NodeStatsResponse
>
Defined in: src/Ruvyrias.ts:658
Get lavalink status from Ruvyrias instance
Parameters
name
string
The name of the node
Returns
Promise
<NodeStatsResponse
>
The stats from the node
getLavalinkVersion()
getLavalinkVersion(
name
):Promise
<string
>
Defined in: src/Ruvyrias.ts:672
Get the current lavalink version of the node
Parameters
name
string
The name of the node
Returns
Promise
<string
>
The version of the node
getMaxListeners()
getMaxListeners():
number
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:773
Returns the current max listener value for the EventEmitter
which is either
set by emitter.setMaxListeners(n)
or defaults to EventEmitter.defaultMaxListeners.
Returns
number
Since
v1.0.0
getNode()
Defined in: src/Ruvyrias.ts:491
Retrieves a node or an array of nodes from the Ruvyrias instance based on the specified identifier.
Parameters
identifier
string
= 'auto'
Node name. If set to 'auto', it returns the least used nodes.
Returns
A Node instance or an array of Node instances.
getNodeByRegion()
getNodeByRegion(
region
):Node
[]
Defined in: src/Ruvyrias.ts:469
Retrieves an array of nodes from the Ruvyrias instance based on the specified region.
Parameters
region
string
Region of the node.
Returns
Node
[]
An array of Node instances.
init()
init(
client
):Promise
<Ruvyrias
>
Defined in: src/Ruvyrias.ts:352
Initializes the Ruvyrias instance with the specified VoiceClient.
Parameters
client
any
VoiceClient for the Ruvyrias library to use to connect to the Lavalink node server (discord.js, eris, oceanic).
Returns
Promise
<Ruvyrias
>
- The current Ruvyrias instance.
listenerCount()
listenerCount<
K
>(eventName
,listener?
):number
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:867
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
K
K
Parameters
eventName
The name of the event being listened for
string
| symbol
listener?
Function
The event handler function
Returns
number
Since
v3.2.0
listeners()
listeners<
K
>(eventName
):Function
[]
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:786
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
K
K
Parameters
eventName
string
| symbol
Returns
Function
[]
Since
v0.1.26
off()
off<
K
>(event
,listener
):this
Defined in: src/Ruvyrias.ts:312
Type Parameters
K
K
extends keyof RuvyriasEvents
Parameters
event
K
listener
Returns
this
on()
on<
K
>(event
,listener
):this
Defined in: src/Ruvyrias.ts:309
Type Parameters
K
K
extends keyof RuvyriasEvents
Parameters
event
K
listener
Returns
this
once()
once<
K
>(event
,listener
):this
Defined in: src/Ruvyrias.ts:310
Type Parameters
K
K
extends keyof RuvyriasEvents
Parameters
event
K
listener
Returns
this
packetUpdate()
packetUpdate(
packet
):Promise
<void
>
Defined in: src/Ruvyrias.ts:418
Handles Voice State Update and Voice Server Update packets from the Discord API.
Parameters
packet
Packet from Discord API.
Returns
Promise
<void
>
prependListener()
prependListener<
K
>(eventName
,listener
):this
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:885
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
K
K
Parameters
eventName
The name of the event.
string
| symbol
listener
(...args
) => void
The callback function
Returns
this
Since
v6.0.0
prependOnceListener()
prependOnceListener<
K
>(eventName
,listener
):this
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:901
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
K
K
Parameters
eventName
The name of the event.
string
| symbol
listener
(...args
) => void
The callback function
Returns
this
Since
v6.0.0
rawListeners()
rawListeners<
K
>(eventName
):Function
[]
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:817
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
K
Parameters
eventName
string
| symbol
Returns
Function
[]
Since
v9.4.0
removeAllListeners()
removeAllListeners(
eventName?
):this
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:757
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
eventName?
string
| symbol
Returns
this
Since
v0.1.26
removeConnection()
removeConnection(
guildId
):Promise
<boolean
>
Defined in: src/Ruvyrias.ts:578
Removes a player associated with the specified guild from Ruvyrias instance.
Parameters
guildId
string
The ID of the guild for which to remove the player.
Returns
Promise
<boolean
>
A promise that resolves to true if the player is successfully removed; otherwise, false.
removeListener()
removeListener<
K
>(eventName
,listener
):this
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:741
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
K
K
Parameters
eventName
string
| symbol
listener
(...args
) => void
Returns
this
Since
v0.1.26
resolve()
resolve(
options
,node?
):Promise
<Response
>
Defined in: src/Ruvyrias.ts:599
Resolves a track using the specified options and node in Ruvyrias instance.
Parameters
options
The options for resolving the track.
node?
The node to use for resolving the track. If not provided, the least used node will be used.
Returns
Promise
<Response
>
A promise that resolves to a Response object containing information about the resolved track.
setMaxListeners()
setMaxListeners(
n
):this
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:767
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
n
number
Returns
this
Since
v0.3.5
addAbortListener()
static
addAbortListener(signal
,resource
):Disposable
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:436
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 AbortSignal
s 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
(event
) => void
Returns
Disposable
Disposable that removes the abort
listener.
Since
v20.5.0
getEventListeners()
static
getEventListeners(emitter
,name
):Function
[]
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:358
Returns a copy of the array of listeners for the event named eventName
.
For EventEmitter
s this behaves exactly the same as calling .listeners
on
the emitter.
For EventTarget
s 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
[]
Since
v15.2.0, v14.17.0
getMaxListeners()
static
getMaxListeners(emitter
):number
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:387
Returns the currently set max amount of listeners.
For EventEmitter
s this behaves exactly the same as calling .getMaxListeners
on
the emitter.
For EventTarget
s 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
Since
v19.9.0
listenerCount()
static
listenerCount(emitter
,eventName
):number
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:330
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
The emitter to query
eventName
The event name
string
| symbol
Returns
number
Since
v0.9.12
Deprecated
Since v3.2.0 - Use listenerCount
instead.
on()
Call Signature
static
on(emitter
,eventName
,options?
):AsyncIterator
<any
[]>
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:303
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
emitter
EventEmitter
eventName
string
| symbol
options?
StaticEventEmitterIteratorOptions
Returns
AsyncIterator
<any
[]>
An AsyncIterator
that iterates eventName
events emitted by the emitter
Since
v13.6.0, v12.16.0
Call Signature
static
on(emitter
,eventName
,options?
):AsyncIterator
<any
[]>
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:308
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
emitter
EventTarget
eventName
string
options?
StaticEventEmitterIteratorOptions
Returns
AsyncIterator
<any
[]>
An AsyncIterator
that iterates eventName
events emitted by the emitter
Since
v13.6.0, v12.16.0
once()
Call Signature
static
once(emitter
,eventName
,options?
):Promise
<any
[]>
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:217
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
eventName
string
| symbol
options?
StaticEventEmitterOptions
Returns
Promise
<any
[]>
Since
v11.13.0, v10.16.0
Call Signature
static
once(emitter
,eventName
,options?
):Promise
<any
[]>
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:222
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
EventTarget
eventName
string
options?
StaticEventEmitterOptions
Returns
Promise
<any
[]>
Since
v11.13.0, v10.16.0
setMaxListeners()
static
setMaxListeners(n?
, ...eventTargets?
):void
Defined in: node_modules/.pnpm/@types+node@24.5.1/node_modules/@types/node/events.d.ts:402
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.
Returns
void
Since
v15.4.0