Proposed changes
here is a draft of a changelog for cloudflare/workerd#7053
Create AbortSignals outside request handlers in the Workers runtime
You can now create AbortController and AbortSignal objects during module initialization in Cloudflare Workers:
const controller = new AbortController();
const alreadyCancelled = AbortSignal.abort("cancelled");
export default {
async fetch() {
return Response.json({
cancelled: alreadyCancelled.aborted,
});
},
};This change brings Workers in line with browsers and Node.js. Libraries can now create controllers, requests, and writable streams when you import them without encountering an IoContext error.
You can also observe or abort a signal from a different request running in the same isolate. Workerd routes cancellation to the request that owns each pending operation.
Do not use isolate-local signals when your application requires durable cancellation. Cloudflare may route requests to another isolate or restart an isolate at any time. Use a Durable Object to coordinate those requests.
AbortSignal.timeout() still requires an active request because it schedules a timer.
More consistent event handling
This change also aligns EventTarget behavior with the DOM standard:
- One listener throwing an exception no longer prevents later listeners from running.
abort() no longer throws when an abort listener throws.- Workerd reports listener exceptions through the global
error event and console.
- Workerd removes listeners registered with
{ signal } before it runs abort listeners.
- Events you construct report
isTrusted === false.
Most applications require no changes.
Subject Matter
cloudflare/workerd#7053
Content Location
new changelog. also research docs if there is anything we need to update, like warnings saying that you can't do what is now possible
Additional information
No response
Proposed changes
here is a draft of a changelog for cloudflare/workerd#7053
Create AbortSignals outside request handlers in the Workers runtime
You can now create
AbortControllerandAbortSignalobjects during module initialization in Cloudflare Workers:This change brings Workers in line with browsers and Node.js. Libraries can now create controllers, requests, and writable streams when you import them without encountering an
IoContexterror.You can also observe or abort a signal from a different request running in the same isolate. Workerd routes cancellation to the request that owns each pending operation.
Do not use isolate-local signals when your application requires durable cancellation. Cloudflare may route requests to another isolate or restart an isolate at any time. Use a Durable Object to coordinate those requests.
AbortSignal.timeout()still requires an active request because it schedules a timer.More consistent event handling
This change also aligns
EventTargetbehavior with the DOM standard:abort()no longer throws when an abort listener throws.errorevent and console.{ signal }before it runs abort listeners.isTrusted === false.Most applications require no changes.
Subject Matter
cloudflare/workerd#7053
Content Location
new changelog. also research docs if there is anything we need to update, like warnings saying that you can't do what is now possible
Additional information
No response