AbortSignal.abort() is a static method that allows creating a new AbortSignal object that is already aborted. It is similar in spirit to Promise.reject(), and provides improved developer ergonomics.
Web developers have found aborted AbortSignal objects to be useful for a variety of purposes. It signifies to JavaScript APIs that no work should be done. However currently, creating an already-aborted AbortSignal object requires jumping through quite a few hoops: const controller = new AbortController(); controller.abort(); return controller.signal; A new AbortSignal.abort() factory function simplifies this to just return AbortSignal.abort();
Explainers: https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal/abort