Allow adding additional functions to `_worker.js`

[smitssjors]

Describe the problem

Cloudflare Queues is currently in open beta. It would be nice to be able to consume messages from the same worker that handles HTTP requests, as opposed to having to creating a separate worker. For a worker to consume from a queue a new queue function needs to be defined on the worker object.

// worker.js
export default {
  async fetch(request, env, ctx) {
    // Handle request...
  },
  async queue(batch, env) {
    // Process batch...
  },
};

Currently there is no easy way to add this queue function to the woker object in the generated _worker.js.

Other Cloudflare services such as Email Workers follow a similar approach.

Describe the proposed solution

I'd suggest a special src/cloudflare-worker.js file which would export functions such as queue which then during compilation get added to the _worker.js file.

// src/cloudflare-worker.js

export const queue = (batch, env) =>  // Process batch...

Alternatives considered

No response

Importance

would make my life easier

Additional Information

No response

[a-hariti]

How would the local DX look like in this context? @smitssjors

I think CF pages works now as long as you don't use anything specific to CF,
miniflare still doesn't cover all the cases as well :(

[smitssjors]

@a-hariti It shouldn't have to be any different than it is now.

[a-hariti]

@smitssjors That's a terrible DX as it only works on the build output

you have to wait for a fresh build on each minute change

[smitssjors]

@a-hariti Yes I agree, but that is out of the scope of this issue. I think that fixing that would require substantial work on how adapters integrate with kit and vite. Currently they just adapt the output of building.

[ghostdevv]

It could be an interesting idea to come up with something similar to how adapter node works. We could have a src/worker.ts file that looks something like:

import { handle } from 'some-virtual-module'

export default {
	fetch: handle
}

[ghostdevv]

Though I only think this would work when deploying to workers right?

[smitssjors]

@ghostdevv To me this looks like a nicer solution. The node adapter docs are not clear where the custom server will live e.g., does kit copy over all files in src or does a user need to copy them over manually?

Though I only think this would work when deploying to workers right?

I think so.

[lsfratel]

+1

[thomasfosterau]

Sorry for resurrecting this issue, but I've got a use case which would greatly benefit from using queues as well as a scheduled worker.

Are there any further requirements for this beyond simply adding an option to the Cloudflare adapter which imports functions from a defined file and adds them to the generated worker?

If not, this seems fairly easy to implement, I might be able to put together a PR this weekend.