FaddAbortSignal
Bun

function

stream.default.addAbortSignal

function addAbortSignal<T extends Stream>(
signal: AbortSignal,
stream: T
): T;

A stream to attach a signal to.

Attaches an AbortSignal to a readable or writeable stream. This lets code control stream destruction using an AbortController.

Calling abort on the AbortController corresponding to the passed AbortSignal will behave the same way as calling .destroy(new AbortError()) on the stream, and controller.error(new AbortError()) for webstreams.

import fs from 'node:fs';

const controller = new AbortController();
const read = addAbortSignal(
  controller.signal,
  fs.createReadStream(('object.json')),
);
// Later, abort the operation closing the stream
controller.abort();

Or using an AbortSignal with a readable stream as an async iterable:

const controller = new AbortController();
setTimeout(() => controller.abort(), 10_000); // set a timeout
const stream = addAbortSignal(
  controller.signal,
  fs.createReadStream(('object.json')),
);
(async () => {
  try {
    for await (const chunk of stream) {
      await process(chunk);
    }
  } catch (e) {
    if (e.name === 'AbortError') {
      // The operation was cancelled
    } else {
      throw e;
    }
  }
})();

Or using an AbortSignal with a ReadableStream:

const controller = new AbortController();
const rs = new ReadableStream({
  start(controller) {
    controller.enqueue('hello');
    controller.enqueue('world');
    controller.close();
  },
});

addAbortSignal(controller.signal, rs);

finished(rs, (err) => {
  if (err) {
    if (err.name === 'AbortError') {
      // The operation was cancelled
    }
  }
});

const reader = rs.getReader();

reader.read().then(({ value, done }) => {
  console.log(value); // hello
  console.log(done); // false
  controller.abort();
});
@param signal

A signal representing possible cancellation

@param stream

A stream to attach a signal to.

Referenced types

class AbortSignal

A signal object that allows you to communicate with a DOM request (such as a Fetch) and abort it if required via an AbortController object.

MDN Reference

  • readonly aborted: boolean

    Returns true if this AbortSignal's AbortController has signaled to abort, and false otherwise.

    MDN Reference

  • onabort: null | (this: AbortSignal, ev: Event) => any
  • readonly reason: any
  • addEventListener<K extends 'abort'>(
    type: K,
    listener: (this: AbortSignal, ev: AbortSignalEventMap[K]) => any,
    options?: boolean | AddEventListenerOptions
    ): void;

    Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

    The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

    When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.

    When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.

    When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

    If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

    The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

    MDN Reference

  • event: Event
    ): boolean;

    Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.

  • removeEventListener<K extends 'abort'>(
    type: K,
    listener: (this: AbortSignal, ev: AbortSignalEventMap[K]) => any,
    options?: boolean | EventListenerOptions
    ): void;

    Removes the event listener in target's event listener list with the same type, callback, and options.

    MDN Reference

  • static abort(
    reason?: any
  • static timeout(
    milliseconds: number