deadline

Create an AbortController which aborts after a set number of milliseconds (a deadline)

Works with browsers, NodeJS (16+), and spec-compliant polyfills.

Usage

Basic

import { createDeadline } from "abortcontroller-deadline";

// create an AbortController which aborts after 500 ms
const controller = createDeadline(500);

// use the controller! in this case, it ensures the fetch takes no longer than 500ms
try {
  const response = await fetch("https://example.com", {
    signal: controller.signal,
  });
  const data = await response.json();
} catch (error) {
  if (error instanceof fetch.AbortError) {
    console.log("Deadline exceeded");
  }
}

Connecting existing signals

You can chain the output of other AbortSignals into the deadline: if any of the signals aborts before the deadline, the deadline controller will be aborted too:

const parentController = new AbortController();
const anotherController = new AbortController();

// if either parentController or anotherController abort, deadlineController
// will also abort, even if 500ms haven't passed
const deadlineController = createDeadline(
  500,
  parentController.signal,
  anotherController.signal
);

Cleaning up timeouts / deadlines

Internally, the deadline is triggered by a timeout (from setTimeout()). While not required, it is a good practice to clean up any unused timeouts.

createDeadline() manages this by adding a clearDeadline() to any returned controller:

import { createDeadline } from "abortcontroller-deadline";

const controller = createDeadline(500);

try {
  const response = await fetch("https://example.com", {
    signal: controller.signal,
  });
  /* ... */
} catch (error) {
  /* ... */
} finally {
  // clean up; this works whether or not the deadline occured
  controller.clearDeadline();
}