Skip to content

@ralphschuler.ai function caller.index.<internal>.FormData

Jump to bottom
github-actions edited this page Nov 26, 2023 · 1 revision

Class: FormData

index.<internal>.FormData

Since

v0.9.4

Hierarchy

Table of contents

Constructors

Properties

Methods

Constructors

constructor

• new FormData(options?): FormData

Parameters

Name Type
options? Options

Returns

FormData

Overrides

Readable.constructor

Defined in

node_modules/form-data/index.d.ts:31

Properties

closed

• Readonly closed: boolean

Is true after 'close' has been emitted.

Since

v18.0.0

Inherited from

Readable.closed

Defined in

node_modules/@types/node/stream.d.ts:119

destroyed

• destroyed: boolean

Is true after readable.destroy() has been called.

Since

v8.0.0

Inherited from

Readable.destroyed

Defined in

node_modules/@types/node/stream.d.ts:114

errored

• Readonly errored: null | Error

Returns error if the stream has been destroyed with an error.

Since

v18.0.0

Inherited from

Readable.errored

Defined in

node_modules/@types/node/stream.d.ts:124

readable

• readable: boolean

Is true if it is safe to call readable.read(), which means the stream has not been destroyed or emitted 'error' or 'end'.

Since

v11.4.0

Inherited from

Readable.readable

Defined in

node_modules/@types/node/stream.d.ts:70

readableAborted

• Readonly readableAborted: boolean

Returns whether the stream was destroyed or errored before emitting 'end'.

Since

v16.8.0

Inherited from

Readable.readableAborted

Defined in

node_modules/@types/node/stream.d.ts:64

readableDidRead

• Readonly readableDidRead: boolean

Returns whether 'data' has been emitted.

Since

v16.7.0, v14.18.0

Inherited from

Readable.readableDidRead

Defined in

node_modules/@types/node/stream.d.ts:76

readableEncoding

• Readonly readableEncoding: null | BufferEncoding

Getter for the property encoding of a given Readable stream. The encodingproperty can be set using the readable.setEncoding() method.

Since

v12.7.0

Inherited from

Readable.readableEncoding

Defined in

node_modules/@types/node/stream.d.ts:81

readableEnded

• Readonly readableEnded: boolean

Becomes true when 'end' event is emitted.

Since

v12.9.0

Inherited from

Readable.readableEnded

Defined in

node_modules/@types/node/stream.d.ts:86

readableFlowing

• Readonly readableFlowing: null | boolean

This property reflects the current state of a Readable stream as described in the Three states section.

Since

v9.4.0

Inherited from

Readable.readableFlowing

Defined in

node_modules/@types/node/stream.d.ts:92

readableHighWaterMark

• Readonly readableHighWaterMark: number

Returns the value of highWaterMark passed when creating this Readable.

Since

v9.3.0

Inherited from

Readable.readableHighWaterMark

Defined in

node_modules/@types/node/stream.d.ts:97

readableLength

• Readonly readableLength: number

This property contains the number of bytes (or objects) in the queue ready to be read. The value provides introspection data regarding the status of the highWaterMark.

Since

v9.4.0

Inherited from

Readable.readableLength

Defined in

node_modules/@types/node/stream.d.ts:104

readableObjectMode

• Readonly readableObjectMode: boolean

Getter for the property objectMode of a given Readable stream.

Since

v12.3.0

Inherited from

Readable.readableObjectMode

Defined in

node_modules/@types/node/stream.d.ts:109

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

Readable.captureRejectionSymbol

Defined in

node_modules/@types/node/events.d.ts:402

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

Readable.captureRejections

Defined in

node_modules/@types/node/events.d.ts:409

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.defaultMaxListenersproperty can be used. If this value is not a positive number, a RangeErroris thrown.

Take caution when setting the events.defaultMaxListeners because the change affects allEventEmitter 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 singleEventEmitter, 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

Readable.defaultMaxListeners

Defined in

node_modules/@types/node/events.d.ts:446

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

Readable.errorMonitor

Defined in

node_modules/@types/node/events.d.ts:395

Methods

[asyncDispose]

▸ [asyncDispose](): Promise<void>

Calls readable.destroy() with an AbortError and returns a promise that fulfills when the stream is finished.

Returns

Promise<void>

Since

v20.4.0

Inherited from

Readable.[asyncDispose]

Defined in

node_modules/@types/node/stream.d.ts:651

[asyncIterator]

▸ [asyncIterator](): AsyncIterableIterator<any>

Returns

AsyncIterableIterator<any>

Inherited from

Readable.[asyncIterator]

Defined in

node_modules/@types/node/stream.d.ts:646

[captureRejectionSymbol]

▸ [captureRejectionSymbol](error, event, ...args): void

Parameters

Name Type
error Error
event string
...args any[]

Returns

void

Inherited from

Readable.[captureRejectionSymbol]

Defined in

node_modules/@types/node/events.d.ts:112

_construct

▸ _construct(callback): void

Parameters

Name Type
callback (error?: null | Error) => void

Returns

void

Inherited from

Readable._construct

Defined in

node_modules/@types/node/stream.d.ts:126

_destroy

▸ _destroy(error, callback): void

Parameters

Name Type
error null | Error
callback (error?: null | Error) => void

Returns

void

Inherited from

Readable._destroy

Defined in

node_modules/@types/node/stream.d.ts:566

_read

▸ _read(size): void

Parameters

Name Type
size number

Returns

void

Inherited from

Readable._read

Defined in

node_modules/@types/node/stream.d.ts:127

addListener

▸ addListener(event, listener): FormData

Event emitter The defined events on documents including:

  1. close
  2. data
  3. end
  4. error
  5. pause
  6. readable
  7. resume

Parameters

Name Type
event "close"
listener () => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:590

▸ addListener(event, listener): FormData

Parameters

Name Type
event "data"
listener (chunk: any) => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:591

▸ addListener(event, listener): FormData

Parameters

Name Type
event "end"
listener () => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:592

▸ addListener(event, listener): FormData

Parameters

Name Type
event "error"
listener (err: Error) => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:593

▸ addListener(event, listener): FormData

Parameters

Name Type
event "pause"
listener () => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:594

▸ addListener(event, listener): FormData

Parameters

Name Type
event "readable"
listener () => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:595

▸ addListener(event, listener): FormData

Parameters

Name Type
event "resume"
listener () => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:596

▸ addListener(event, listener): FormData

Parameters

Name Type
event string | symbol
listener (...args: any[]) => void

Returns

FormData

Inherited from

Readable.addListener

Defined in

node_modules/@types/node/stream.d.ts:597

append

▸ append(key, value, options?): void

Parameters

Name Type
key string
value any
options? string | AppendOptions

Returns

void

Defined in

node_modules/form-data/index.d.ts:32

asIndexedPairs

▸ asIndexedPairs(options?): Readable

This method returns a new stream with chunks of the underlying stream paired with a counter in the form [index, chunk]. The first index value is 0 and it increases by 1 for each chunk produced.

Parameters

Name Type
options? Pick<ArrayOptions, "signal">

Returns

Readable

a stream of indexed pairs.

Since

v17.5.0

Inherited from

Readable.asIndexedPairs

Defined in

node_modules/@types/node/stream.d.ts:541

compose

▸ compose<T>(stream, options?): T

Type parameters

Name Type
T extends ReadableStream

Parameters

Name Type
stream ComposeFnParam | T | Iterable<T> | AsyncIterable<T>
options? Object
options.signal AbortSignal

Returns

T

Inherited from

Readable.compose

Defined in

node_modules/@types/node/stream.d.ts:35

destroy

▸ destroy(error?): FormData

Destroy the stream. Optionally emit an 'error' event, and emit a 'close'event (unless emitClose is set to false). After this call, the readable stream will release any internal resources and subsequent calls to push()will be ignored.

Once destroy() has been called any further calls will be a no-op and no further errors except from _destroy() may be emitted as 'error'.

Implementors should not override this method, but instead implement readable._destroy().

Parameters

Name Type Description
error? Error Error which will be passed as payload in 'error' event

Returns

FormData

Since

v8.0.0

Inherited from

Readable.destroy

Defined in

node_modules/@types/node/stream.d.ts:578

drop

▸ drop(limit, options?): Readable

This method returns a new stream with the first limit chunks dropped from the start.

Parameters

Name Type Description
limit number the number of chunks to drop from the readable.
options? Pick<ArrayOptions, "signal"> -

Returns

Readable

a stream with limit chunks dropped from the start.

Since

v17.5.0

Inherited from

Readable.drop

Defined in

node_modules/@types/node/stream.d.ts:527

emit

▸ emit(event): 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.

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

Parameters

Name Type
event "close"

Returns

boolean

Since

v0.1.26

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:598

▸ emit(event, chunk): boolean

Parameters

Name Type
event "data"
chunk any

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:599

▸ emit(event): boolean

Parameters

Name Type
event "end"

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:600

▸ emit(event, err): boolean

Parameters

Name Type
event "error"
err Error

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:601

▸ emit(event): boolean

Parameters

Name Type
event "pause"

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:602

▸ emit(event): boolean

Parameters

Name Type
event "readable"

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:603

▸ emit(event): boolean

Parameters

Name Type
event "resume"

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:604

▸ emit(event, ...args): boolean

Parameters

Name Type
event string | symbol
...args any[]

Returns

boolean

Inherited from

Readable.emit

Defined in

node_modules/@types/node/stream.d.ts:605

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)[]

Since

v6.0.0

Inherited from

Readable.eventNames

Defined in

node_modules/@types/node/events.d.ts:870

every

▸ every(fn, options?): Promise<boolean>

This method is similar to Array.prototype.every and calls fn on each chunk in the stream to check if all awaited return values are truthy value for fn. Once an fn call on a chunk awaited return value is falsy, the stream is destroyed and the promise is fulfilled with false. If all of the fn calls on the chunks return a truthy value, the promise is fulfilled with true.

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => boolean | Promise<boolean> a function to call on each chunk of the stream. Async or not.
options? ArrayOptions -

Returns

Promise<boolean>

a promise evaluating to true if fn returned a truthy value for every one of the chunks.

Since

v17.5.0

Inherited from

Readable.every

Defined in

node_modules/@types/node/stream.d.ts:506

filter

▸ filter(fn, options?): Readable

This method allows filtering the stream. For each chunk in the stream the fn function will be called and if it returns a truthy value, the chunk will be passed to the result stream. If the fn function returns a promise - that promise will be awaited.

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => boolean | Promise<boolean> a function to filter chunks from the stream. Async or not.
options? ArrayOptions -

Returns

Readable

a stream filtered with the predicate fn.

Since

v17.4.0, v16.14.0

Inherited from

Readable.filter

Defined in

node_modules/@types/node/stream.d.ts:434

find

▸ find<T>(fn, options?): Promise<undefined | T>

This method is similar to Array.prototype.find and calls fn on each chunk in the stream to find a chunk with a truthy value for fn. Once an fn call's awaited return value is truthy, the stream is destroyed and the promise is fulfilled with value for which fn returned a truthy value. If all of the fn calls on the chunks return a falsy value, the promise is fulfilled with undefined.

Type parameters

Name
T

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => data is T a function to call on each chunk of the stream. Async or not.
options? ArrayOptions -

Returns

Promise<undefined | T>

a promise evaluating to the first chunk for which fn evaluated with a truthy value, or undefined if no element was found.

Since

v17.5.0

Inherited from

Readable.find

Defined in

node_modules/@types/node/stream.d.ts:489

▸ find(fn, options?): Promise<any>

Parameters

Name Type
fn (data: any, options?: Pick<ArrayOptions, "signal">) => boolean | Promise<boolean>
options? ArrayOptions

Returns

Promise<any>

Inherited from

Readable.find

Defined in

node_modules/@types/node/stream.d.ts:493

flatMap

▸ flatMap(fn, options?): Readable

This method returns a new stream by applying the given callback to each chunk of the stream and then flattening the result.

It is possible to return a stream or another iterable or async iterable from fn and the result streams will be merged (flattened) into the returned stream.

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => any a function to map over every chunk in the stream. May be async. May be a stream or generator.
options? ArrayOptions -

Returns

Readable

a stream flat-mapped with the function fn.

Since

v17.5.0

Inherited from

Readable.flatMap

Defined in

node_modules/@types/node/stream.d.ts:520

forEach

▸ forEach(fn, options?): Promise<void>

This method allows iterating a stream. For each chunk in the stream the fn function will be called. If the fn function returns a promise - that promise will be awaited.

This method is different from for await...of loops in that it can optionally process chunks concurrently. In addition, a forEach iteration can only be stopped by having passed a signal option and aborting the related AbortController while for await...of can be stopped with break or return. In either case the stream will be destroyed.

This method is different from listening to the 'data' event in that it uses the readable event in the underlying machinary and can limit the number of concurrent fn calls.

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => void | Promise<void> a function to call on each chunk of the stream. Async or not.
options? ArrayOptions -

Returns

Promise<void>

a promise for when the stream has finished.

Since

v17.5.0

Inherited from

Readable.forEach

Defined in

node_modules/@types/node/stream.d.ts:453

getBoundary

▸ getBoundary(): string

Returns

string

Defined in

node_modules/form-data/index.d.ts:40

getBuffer

▸ getBuffer(): Buffer

Returns

Buffer

Defined in

node_modules/form-data/index.d.ts:38

getHeaders

▸ getHeaders(userHeaders?): Headers

Parameters

Name Type
userHeaders? Headers

Returns

Headers

Defined in

node_modules/form-data/index.d.ts:33

getLength

▸ getLength(callback): void

Parameters

Name Type
callback (err: null | Error, length: number) => void

Returns

void

Defined in

node_modules/form-data/index.d.ts:41

getLengthSync

▸ getLengthSync(): number

Returns

number

Defined in

node_modules/form-data/index.d.ts:42

getMaxListeners

▸ getMaxListeners(): number

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

Returns

number

Since

v1.0.0

Inherited from

Readable.getMaxListeners

Defined in

node_modules/@types/node/events.d.ts:722

hasKnownLength

▸ hasKnownLength(): boolean

Returns

boolean

Defined in

node_modules/form-data/index.d.ts:43

isPaused

▸ isPaused(): boolean

The readable.isPaused() method returns the current operating state of theReadable. This is used primarily by the mechanism that underlies thereadable.pipe() method. In most typical cases, there will be no reason to use this method directly.

const readable = new stream.Readable();

readable.isPaused(); // === false
readable.pause();
readable.isPaused(); // === true
readable.resume();
readable.isPaused(); // === false

Returns

boolean

Since

v0.11.14

Inherited from

Readable.isPaused

Defined in

node_modules/@types/node/stream.d.ts:287

iterator

▸ iterator(options?): AsyncIterableIterator<any>

The iterator created by this method gives users the option to cancel the destruction of the stream if the for await...of loop is exited by return, break, or throw, or if the iterator should destroy the stream if the stream emitted an error during iteration.

Parameters

Name Type Description
options? Object -
options.destroyOnReturn? boolean When set to false, calling return on the async iterator, or exiting a for await...of iteration using a break, return, or throw will not destroy the stream. Default: true.

Returns

AsyncIterableIterator<any>

Since

v16.3.0

Inherited from

Readable.iterator

Defined in

node_modules/@types/node/stream.d.ts:417

listenerCount

▸ listenerCount(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.

Parameters

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

Returns

number

Since

v3.2.0

Inherited from

Readable.listenerCount

Defined in

node_modules/@types/node/events.d.ts:816

listeners

▸ 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] ]

Parameters

Name Type
eventName string | symbol

Returns

Function[]

Since

v0.1.26

Inherited from

Readable.listeners

Defined in

node_modules/@types/node/events.d.ts:735

map

▸ map(fn, options?): Readable

This method allows mapping over the stream. The fn function will be called for every chunk in the stream. If the fn function returns a promise - that promise will be awaited before being passed to the result stream.

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => any a function to map over every chunk in the stream. Async or not.
options? ArrayOptions -

Returns

Readable

a stream mapped with the function fn.

Since

v17.4.0, v16.14.0

Inherited from

Readable.map

Defined in

node_modules/@types/node/stream.d.ts:425

off

▸ off(eventName, listener): FormData

Alias for emitter.removeListener().

Parameters

Name Type
eventName string | symbol
listener (...args: any[]) => void

Returns

FormData

Since

v10.0.0

Inherited from

Readable.off

Defined in

node_modules/@types/node/events.d.ts:695

on

▸ on(event, listener): FormData

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 eventNameand 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. Theemitter.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

Parameters

Name Type Description
event "close" The name of the event.
listener () => void The callback function

Returns

FormData

Since

v0.1.101

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:606

▸ on(event, listener): FormData

Parameters

Name Type
event "data"
listener (chunk: any) => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:607

▸ on(event, listener): FormData

Parameters

Name Type
event "end"
listener () => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:608

▸ on(event, listener): FormData

Parameters

Name Type
event "error"
listener (err: Error) => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:609

▸ on(event, listener): FormData

Parameters

Name Type
event "pause"
listener () => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:610

▸ on(event, listener): FormData

Parameters

Name Type
event "readable"
listener () => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:611

▸ on(event, listener): FormData

Parameters

Name Type
event "resume"
listener () => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:612

▸ on(event, listener): FormData

Parameters

Name Type
event string | symbol
listener (...args: any[]) => void

Returns

FormData

Inherited from

Readable.on

Defined in

node_modules/@types/node/stream.d.ts:613

once

▸ once(event, listener): FormData

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.

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

Parameters

Name Type Description
event "close" The name of the event.
listener () => void The callback function

Returns

FormData

Since

v0.3.0

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:614

▸ once(event, listener): FormData

Parameters

Name Type
event "data"
listener (chunk: any) => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:615

▸ once(event, listener): FormData

Parameters

Name Type
event "end"
listener () => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:616

▸ once(event, listener): FormData

Parameters

Name Type
event "error"
listener (err: Error) => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:617

▸ once(event, listener): FormData

Parameters

Name Type
event "pause"
listener () => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:618

▸ once(event, listener): FormData

Parameters

Name Type
event "readable"
listener () => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:619

▸ once(event, listener): FormData

Parameters

Name Type
event "resume"
listener () => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:620

▸ once(event, listener): FormData

Parameters

Name Type
event string | symbol
listener (...args: any[]) => void

Returns

FormData

Inherited from

Readable.once

Defined in

node_modules/@types/node/stream.d.ts:621

pause

▸ pause(): FormData

The readable.pause() method will cause a stream in flowing mode to stop emitting 'data' events, switching out of flowing mode. Any data that becomes available will remain in the internal buffer.

const readable = getReadableStreamSomehow();
readable.on('data', (chunk) => {
  console.log(`Received ${chunk.length} bytes of data.`);
  readable.pause();
  console.log('There will be no additional data for 1 second.');
  setTimeout(() => {
    console.log('Now data will start flowing again.');
    readable.resume();
  }, 1000);
});

The readable.pause() method has no effect if there is a 'readable'event listener.

Returns

FormData

Since

v0.9.4

Inherited from

Readable.pause

Defined in

node_modules/@types/node/stream.d.ts:251

pipe

▸ pipe<T>(destination, options?): T

Type parameters

Name Type
T extends WritableStream

Parameters

Name Type
destination T
options? Object
options.end? boolean

Returns

T

Inherited from

Readable.pipe

Defined in

node_modules/@types/node/stream.d.ts:29

prependListener

▸ prependListener(event, listener): FormData

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.

Parameters

Name Type Description
event "close" The name of the event.
listener () => void The callback function

Returns

FormData

Since

v6.0.0

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:622

▸ prependListener(event, listener): FormData

Parameters

Name Type
event "data"
listener (chunk: any) => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:623

▸ prependListener(event, listener): FormData

Parameters

Name Type
event "end"
listener () => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:624

▸ prependListener(event, listener): FormData

Parameters

Name Type
event "error"
listener (err: Error) => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:625

▸ prependListener(event, listener): FormData

Parameters

Name Type
event "pause"
listener () => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:626

▸ prependListener(event, listener): FormData

Parameters

Name Type
event "readable"
listener () => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:627

▸ prependListener(event, listener): FormData

Parameters

Name Type
event "resume"
listener () => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:628

▸ prependListener(event, listener): FormData

Parameters

Name Type
event string | symbol
listener (...args: any[]) => void

Returns

FormData

Inherited from

Readable.prependListener

Defined in

node_modules/@types/node/stream.d.ts:629

prependOnceListener

▸ prependOnceListener(event, listener): FormData

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.

Parameters

Name Type Description
event "close" The name of the event.
listener () => void The callback function

Returns

FormData

Since

v6.0.0

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:630

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event "data"
listener (chunk: any) => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:631

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event "end"
listener () => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:632

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event "error"
listener (err: Error) => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:633

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event "pause"
listener () => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:634

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event "readable"
listener () => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:635

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event "resume"
listener () => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:636

▸ prependOnceListener(event, listener): FormData

Parameters

Name Type
event string | symbol
listener (...args: any[]) => void

Returns

FormData

Inherited from

Readable.prependOnceListener

Defined in

node_modules/@types/node/stream.d.ts:637

push

▸ push(chunk, encoding?): boolean

Parameters

Name Type
chunk any
encoding? BufferEncoding

Returns

boolean

Inherited from

Readable.push

Defined in

node_modules/@types/node/stream.d.ts:407

rawListeners

▸ 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()).

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');

Parameters

Name Type
eventName string | symbol

Returns

Function[]

Since

v9.4.0

Inherited from

Readable.rawListeners

Defined in

node_modules/@types/node/events.d.ts:766

read

▸ read(size?): any

The readable.read() method reads data out of the internal buffer and returns it. If no data is available to be read, null is returned. By default, the data is returned as a Buffer object unless an encoding has been specified using the readable.setEncoding() method or the stream is operating in object mode.

The optional size argument specifies a specific number of bytes to read. Ifsize bytes are not available to be read, null will be returned _unless_the stream has ended, in which case all of the data remaining in the internal buffer will be returned.

If the size argument is not specified, all of the data contained in the internal buffer will be returned.

The size argument must be less than or equal to 1 GiB.

The readable.read() method should only be called on Readable streams operating in paused mode. In flowing mode, readable.read() is called automatically until the internal buffer is fully drained.

const readable = getReadableStreamSomehow();

// 'readable' may be triggered multiple times as data is buffered in
readable.on('readable', () => {
  let chunk;
  console.log('Stream is readable (new data received in buffer)');
  // Use a loop to make sure we read all currently available data
  while (null !== (chunk = readable.read())) {
    console.log(`Read ${chunk.length} bytes of data...`);
  }
});

// 'end' will be triggered once when there is no more data available
readable.on('end', () => {
  console.log('Reached end of stream.');
});

Each call to readable.read() returns a chunk of data, or null. The chunks are not concatenated. A while loop is necessary to consume all data currently in the buffer. When reading a large file .read() may return null, having consumed all buffered content so far, but there is still more data to come not yet buffered. In this case a new 'readable' event will be emitted when there is more data in the buffer. Finally the 'end' event will be emitted when there is no more data to come.

Therefore to read a file's whole contents from a readable, it is necessary to collect chunks across multiple 'readable' events:

const chunks = [];

readable.on('readable', () => {
  let chunk;
  while (null !== (chunk = readable.read())) {
    chunks.push(chunk);
  }
});

readable.on('end', () => {
  const content = chunks.join('');
});

A Readable stream in object mode will always return a single item from a call to readable.read(size), regardless of the value of thesize argument.

If the readable.read() method returns a chunk of data, a 'data' event will also be emitted.

Calling read after the 'end' event has been emitted will return null. No runtime error will be raised.

Parameters

Name Type Description
size? number Optional argument to specify how much data to read.

Returns

any

Since

v0.9.4

Inherited from

Readable.read

Defined in

node_modules/@types/node/stream.d.ts:204

reduce

▸ reduce<T>(fn, initial?, options?): Promise<T>

This method calls fn on each chunk of the stream in order, passing it the result from the calculation on the previous element. It returns a promise for the final value of the reduction.

If no initial value is supplied the first chunk of the stream is used as the initial value. If the stream is empty, the promise is rejected with a TypeError with the ERR_INVALID_ARGS code property.

The reducer function iterates the stream element-by-element which means that there is no concurrency parameter or parallelism. To perform a reduce concurrently, you can extract the async function to readable.map method.

Type parameters

Name Type
T any

Parameters

Name Type Description
fn (previous: any, data: any, options?: Pick<ArrayOptions, "signal">) => T a reducer function to call over every chunk in the stream. Async or not.
initial? undefined the initial value to use in the reduction.
options? Pick<ArrayOptions, "signal"> -

Returns

Promise<T>

a promise for the final value of the reduction.

Since

v17.5.0

Inherited from

Readable.reduce

Defined in

node_modules/@types/node/stream.d.ts:556

▸ reduce<T>(fn, initial, options?): Promise<T>

Type parameters

Name Type
T any

Parameters

Name Type
fn (previous: T, data: any, options?: Pick<ArrayOptions, "signal">) => T
initial T
options? Pick<ArrayOptions, "signal">

Returns

Promise<T>

Inherited from

Readable.reduce

Defined in

node_modules/@types/node/stream.d.ts:561

removeAllListeners

▸ removeAllListeners(event?): FormData

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
event? string | symbol

Returns

FormData

Since

v0.1.26

Inherited from

Readable.removeAllListeners

Defined in

node_modules/@types/node/events.d.ts:706

removeListener

▸ removeListener(event, listener): FormData

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.

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.

Parameters

Name Type
event "close"
listener () => void

Returns

FormData

Since

v0.1.26

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:638

▸ removeListener(event, listener): FormData

Parameters

Name Type
event "data"
listener (chunk: any) => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:639

▸ removeListener(event, listener): FormData

Parameters

Name Type
event "end"
listener () => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:640

▸ removeListener(event, listener): FormData

Parameters

Name Type
event "error"
listener (err: Error) => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:641

▸ removeListener(event, listener): FormData

Parameters

Name Type
event "pause"
listener () => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:642

▸ removeListener(event, listener): FormData

Parameters

Name Type
event "readable"
listener () => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:643

▸ removeListener(event, listener): FormData

Parameters

Name Type
event "resume"
listener () => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:644

▸ removeListener(event, listener): FormData

Parameters

Name Type
event string | symbol
listener (...args: any[]) => void

Returns

FormData

Inherited from

Readable.removeListener

Defined in

node_modules/@types/node/stream.d.ts:645

resume

▸ resume(): FormData

The readable.resume() method causes an explicitly paused Readable stream to resume emitting 'data' events, switching the stream into flowing mode.

The readable.resume() method can be used to fully consume the data from a stream without actually processing any of that data:

getReadableStreamSomehow()
  .resume()
  .on('end', () => {
    console.log('Reached the end, but did not read anything.');
  });

The readable.resume() method has no effect if there is a 'readable'event listener.

Returns

FormData

Since

v0.9.4

Inherited from

Readable.resume

Defined in

node_modules/@types/node/stream.d.ts:270

setBoundary

▸ setBoundary(boundary): void

Parameters

Name Type
boundary string

Returns

void

Defined in

node_modules/form-data/index.d.ts:39

setEncoding

▸ setEncoding(encoding): FormData

The readable.setEncoding() method sets the character encoding for data read from the Readable stream.

By default, no encoding is assigned and stream data will be returned asBuffer objects. Setting an encoding causes the stream data to be returned as strings of the specified encoding rather than as Bufferobjects. For instance, calling readable.setEncoding('utf8') will cause the output data to be interpreted as UTF-8 data, and passed as strings. Callingreadable.setEncoding('hex') will cause the data to be encoded in hexadecimal string format.

The Readable stream will properly handle multi-byte characters delivered through the stream that would otherwise become improperly decoded if simply pulled from the stream as Buffer objects.

const readable = getReadableStreamSomehow();
readable.setEncoding('utf8');
readable.on('data', (chunk) => {
  assert.equal(typeof chunk, 'string');
  console.log('Got %d characters of string data:', chunk.length);
});

Parameters

Name Type Description
encoding BufferEncoding The encoding to use.

Returns

FormData

Since

v0.9.4

Inherited from

Readable.setEncoding

Defined in

node_modules/@types/node/stream.d.ts:229

setMaxListeners

▸ setMaxListeners(n): FormData

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.

Parameters

Name Type
n number

Returns

FormData

Since

v0.3.5

Inherited from

Readable.setMaxListeners

Defined in

node_modules/@types/node/events.d.ts:716

some

▸ some(fn, options?): Promise<boolean>

This method is similar to Array.prototype.some and calls fn on each chunk in the stream until the awaited return value is true (or any truthy value). Once an fn call on a chunk awaited return value is truthy, the stream is destroyed and the promise is fulfilled with true. If none of the fn calls on the chunks return a truthy value, the promise is fulfilled with false.

Parameters

Name Type Description
fn (data: any, options?: Pick<ArrayOptions, "signal">) => boolean | Promise<boolean> a function to call on each chunk of the stream. Async or not.
options? ArrayOptions -

Returns

Promise<boolean>

a promise evaluating to true if fn returned a truthy value for at least one of the chunks.

Since

v17.5.0

Inherited from

Readable.some

Defined in

node_modules/@types/node/stream.d.ts:475

submit

▸ submit(params, callback?): ClientRequest

Parameters

Name Type
params string | SubmitOptions
callback? (error: null | Error, response: IncomingMessage) => void

Returns

ClientRequest

Defined in

node_modules/form-data/index.d.ts:34

take

▸ take(limit, options?): Readable

This method returns a new stream with the first limit chunks.

Parameters

Name Type Description
limit number the number of chunks to take from the readable.
options? Pick<ArrayOptions, "signal"> -

Returns

Readable

a stream with limit chunks taken.

Since

v17.5.0

Inherited from

Readable.take

Defined in

node_modules/@types/node/stream.d.ts:534

toArray

▸ toArray(options?): Promise<any[]>

This method allows easily obtaining the contents of a stream.

As this method reads the entire stream into memory, it negates the benefits of streams. It's intended for interoperability and convenience, not as the primary way to consume streams.

Parameters

Name Type
options? Pick<ArrayOptions, "signal">

Returns

Promise<any[]>

a promise containing an array with the contents of the stream.

Since

v17.5.0

Inherited from

Readable.toArray

Defined in

node_modules/@types/node/stream.d.ts:465

unpipe

▸ unpipe(destination?): FormData

The readable.unpipe() method detaches a Writable stream previously attached using the pipe method.

If the destination is not specified, then all pipes are detached.

If the destination is specified, but no pipe is set up for it, then the method does nothing.

const fs = require('node:fs');
const readable = getReadableStreamSomehow();
const writable = fs.createWriteStream('file.txt');
// All the data from readable goes into 'file.txt',
// but only for the first second.
readable.pipe(writable);
setTimeout(() => {
  console.log('Stop writing to file.txt.');
  readable.unpipe(writable);
  console.log('Manually close the file stream.');
  writable.end();
}, 1000);

Parameters

Name Type Description
destination? WritableStream Optional specific stream to unpipe

Returns

FormData

Since

v0.9.4

Inherited from

Readable.unpipe

Defined in

node_modules/@types/node/stream.d.ts:314

unshift

▸ unshift(chunk, encoding?): void

Passing chunk as null signals the end of the stream (EOF) and behaves the same as readable.push(null), after which no more data can be written. The EOF signal is put at the end of the buffer and any buffered data will still be flushed.

The readable.unshift() method pushes a chunk of data back into the internal buffer. This is useful in certain situations where a stream is being consumed by code that needs to "un-consume" some amount of data that it has optimistically pulled out of the source, so that the data can be passed on to some other party.

The stream.unshift(chunk) method cannot be called after the 'end' event has been emitted or a runtime error will be thrown.

Developers using stream.unshift() often should consider switching to use of a Transform stream instead. See the API for stream implementers section for more information.

// Pull off a header delimited by \n\n.
// Use unshift() if we get too much.
// Call the callback with (error, header, stream).
const { StringDecoder } = require('node:string_decoder');
function parseHeader(stream, callback) {
  stream.on('error', callback);
  stream.on('readable', onReadable);
  const decoder = new StringDecoder('utf8');
  let header = '';
  function onReadable() {
    let chunk;
    while (null !== (chunk = stream.read())) {
      const str = decoder.write(chunk);
      if (str.includes('\n\n')) {
        // Found the header boundary.
        const split = str.split(/\n\n/);
        header += split.shift();
        const remaining = split.join('\n\n');
        const buf = Buffer.from(remaining, 'utf8');
        stream.removeListener('error', callback);
        // Remove the 'readable' listener before unshifting.
        stream.removeListener('readable', onReadable);
        if (buf.length)
          stream.unshift(buf);
        // Now the body of the message can be read from the stream.
        callback(null, header, stream);
        return;
      }
      // Still reading the header.
      header += str;
    }
  }
}

Unlike push, stream.unshift(chunk) will not end the reading process by resetting the internal reading state of the stream. This can cause unexpected results if readable.unshift() is called during a read (i.e. from within a _read implementation on a custom stream). Following the call to readable.unshift() with an immediate push will reset the reading state appropriately, however it is best to simply avoid calling readable.unshift() while in the process of performing a read.

Parameters

Name Type Description
chunk any Chunk of data to unshift onto the read queue. For streams not operating in object mode, chunk must be a string, Buffer, Uint8Array, or null. For object mode streams, chunk may be any JavaScript value.
encoding? BufferEncoding Encoding of string chunks. Must be a valid Buffer encoding, such as 'utf8' or 'ascii'.

Returns

void

Since

v0.9.11

Inherited from

Readable.unshift

Defined in

node_modules/@types/node/stream.d.ts:380

wrap

▸ wrap(stream): FormData

Prior to Node.js 0.10, streams did not implement the entire node:streammodule API as it is currently defined. (See Compatibility for more information.)

When using an older Node.js library that emits 'data' events and has a pause method that is advisory only, thereadable.wrap() method can be used to create a Readable stream that uses the old stream as its data source.

It will rarely be necessary to use readable.wrap() but the method has been provided as a convenience for interacting with older Node.js applications and libraries.

const { OldReader } = require('./old-api-module.js');
const { Readable } = require('node:stream');
const oreader = new OldReader();
const myReader = new Readable().wrap(oreader);

myReader.on('readable', () => {
  myReader.read(); // etc.
});

Parameters

Name Type Description
stream ReadableStream An "old style" readable stream

Returns

FormData

Since

v0.9.4

Inherited from

Readable.wrap

Defined in

node_modules/@types/node/stream.d.ts:406

addAbortListener

▸ 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
signal AbortSignal
resource (event: Event) => void

Returns

Disposable

Disposable that removes the abort listener.

Since

v20.5.0

Inherited from

Readable.addAbortListener

Defined in

node_modules/@types/node/events.d.ts:387

from

▸ from(iterable, options?): Readable

A utility method for creating Readable Streams out of iterators.

Parameters

Name Type
iterable Iterable<any> | AsyncIterable<any>
options? ReadableOptions

Returns

Readable

Inherited from

Readable.from

Defined in

node_modules/@types/node/stream.d.ts:53

fromWeb

▸ fromWeb(readableStream, options?): Readable

A utility method for creating a Readable from a web ReadableStream.

Parameters

Name Type
readableStream ReadableStream<any>
options? Pick<ReadableOptions, "signal" | "highWaterMark" | "objectMode" | "encoding">

Returns

Readable

Since

v17.0.0

Inherited from

Readable.fromWeb

Defined in

node_modules/@types/node/stream.d.ts:967

getEventListeners

▸ 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
emitter EventEmitter | _DOMEventTarget
name string | symbol

Returns

Function[]

Since

v15.2.0, v14.17.0

Inherited from

Readable.getEventListeners

Defined in

node_modules/@types/node/events.d.ts:308

getMaxListeners

▸ 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
emitter EventEmitter | _DOMEventTarget

Returns

number

Since

v19.9.0

Inherited from

Readable.getMaxListeners

Defined in

node_modules/@types/node/events.d.ts:337

isDisturbed

▸ isDisturbed(stream): boolean

Returns whether the stream has been read from or cancelled.

Parameters

Name Type
stream Readable | ReadableStream

Returns

boolean

Since

v16.8.0

Inherited from

Readable.isDisturbed

Defined in

node_modules/@types/node/stream.d.ts:58

listenerCount

▸ listenerCount(emitter, eventName): number

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

Since

v0.9.12

Deprecated

Since v3.2.0 - Use listenerCount instead.

Inherited from

Readable.listenerCount

Defined in

node_modules/@types/node/events.d.ts:280

on

▸ 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

Name Type Description
emitter EventEmitter -
eventName string The name of the event being listened for
options? StaticEventEmitterOptions -

Returns

AsyncIterableIterator<any>

that iterates eventName events emitted by the emitter

Since

v13.6.0, v12.16.0

Inherited from

Readable.on

Defined in

node_modules/@types/node/events.d.ts:258

once

▸ 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
emitter _NodeEventTarget
eventName string | symbol
options? StaticEventEmitterOptions

Returns

Promise<any[]>

Since

v11.13.0, v10.16.0

Inherited from

Readable.once

Defined in

node_modules/@types/node/events.d.ts:193

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

Parameters

Name Type
emitter _DOMEventTarget
eventName string
options? StaticEventEmitterOptions

Returns

Promise<any[]>

Inherited from

Readable.once

Defined in

node_modules/@types/node/events.d.ts:198

setMaxListeners

▸ 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 (EventEmitter | _DOMEventTarget)[] -

Returns

void

Since

v15.4.0

Inherited from

Readable.setMaxListeners

Defined in

node_modules/@types/node/events.d.ts:352

toWeb

▸ toWeb(streamReadable): ReadableStream<any>

A utility method for creating a web ReadableStream from a Readable.

Parameters

Name Type
streamReadable Readable

Returns

ReadableStream<any>

Since

v17.0.0

Inherited from

Readable.toWeb

Defined in

node_modules/@types/node/stream.d.ts:976

Typescript Libraries

Modules

Namespaces

Clone this wiki locally