Category: error Since: 1.1.0 Tags: error, abort, dom-exception, type-guard, cancellation

isAbortError

Checks whether a value is a DOMException with name === "AbortError".

Usage

import { isAbortError } from "@petr-ptacek/js-core";

try {
  await fetch("/api/data", { signal });
} catch (error) {
  if (isAbortError(error)) {
    return; // request was cancelled — ignore
  }
  throw error;
}

Why This Utility Exists

AbortError is not a dedicated class — it is a DOMException instance with name === "AbortError". Checking this inline is repetitive and error-prone. This utility provides a reusable, readable predicate that also acts as a TypeScript type guard.

Signature

function isAbortError(error: unknown): error is DOMException;

Parameters

• error (unknown): The value to test.

Return Type

Returns true if error is a DOMException with name === "AbortError", otherwise false.

When true, TypeScript narrows error to DOMException.

Design Notes

AbortError is thrown by browser APIs that support cancellation via AbortSignal — most notably fetch. The check requires both an instanceof DOMException guard and a name comparison, since DOMException uses the name property to differentiate error subtypes rather than separate subclasses.

When To Use

Use isAbortError when you need to:

• distinguish abort errors from other errors in a catch block
• silently ignore aborted requests in UI components
• handle cancellation cleanly without inline instanceof checks

When Not To Use

Avoid when:

• you want to handle all errors uniformly without branching
• you need to detect timeouts or other DOMException subtypes (check error.name directly)

Summary

isAbortError is a minimal type guard for identifying AbortError instances, eliminating repetitive inline checks in async error handling.

Snippets

basic.ts

import { isAbortError } from "@petr-ptacek/js-core";

// Basic check
console.log(isAbortError(new DOMException("Aborted", "AbortError"))); // true
console.log(isAbortError(new Error("Aborted"))); // false
console.log(isAbortError(null)); // false

// Type guard usage in a try/catch block
const controller = new AbortController();

// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-expect-error
async function _fetchWithAbort(url: string) {
  try {
    const response = await fetch(url, { signal: controller.signal });
    return response.json();
  } catch (error) {
    if (isAbortError(error)) {
      // error is narrowed to DOMException
      console.log("Request was aborted:", error.message);
      return null;
    }
    throw error;
  }
}