setFetchOptionsUpdateCallback not available when bundled with a bundler

[RobQuincey-DC]

This is more a question than an issue.

I'm using setFetchOptions to add a header to my request, specifically a authorization header, like so:

setFetchOptions({ headers: {"Authorization" : "bearer 1234567890"} });

When making a request, such as

const endpoint = await new WmsEndpoint(baseUrl).isReady();

The header doesn't appear to be sent with the web request. In my instance, this means the GetCapabilities request does not include the required Authorization header and I don't get the details I need.

If I switch off the web worker by calling enableFallbackWithoutWorker(), then it works and the Authorization header is appended.

Is this is a known limitation to how the web worker works or is it a bug? I'll admit to not being entirely familiar with web workers and what restrictions they may have.

[jahow]

Hey, it looks like a bug but I'm not 100% sure. Does it work if you try sending a custom header, like { "X-Test": "hello world" }?

[RobQuincey-DC]

Doesn't seem to, but the devtools don't seem to show me the headers. I'll see if I can dig a bit deeper and make a reproduceable example

[RobQuincey-DC]

Ok, looks like it might be a problem my end. I forced ogc-client to send a request to https://httpbin.org/headers and it reported back that it received both X-Test and Authorization

So I must be doing something wrong my end. I'll keep playing, and once I know what's wrong I'll report back here in case anyone else has the same issue and close it off.

[jahow]

Thank you!

Maybe the worker is receiving the new fetch options after doing the fetch requests?

[RobQuincey-DC]

I think the problem is when using webpack as my bundler. When I run the example pages, I can see this bit of code

setFetchOptionsUpdateCallback((options) => {
  const worker = getWorkerInstance();
  if (!worker) return;
  sendTaskRequest('updateFetchOptions', getWorkerInstance(), { options });
});

in src/worker/index.ts is being called on load, which sets up the ability for the fetch options in the worker to be dynamically updated. When I look at my webpack compiled code though, this does not run. In fact, the code does not appear at all in the output bundle. I can only assume that webpack is seeing it as not used and removing it. I may be able to change how webpack handles this particular library, but I did wonder whether there was something I am missing that I can call to 'initialize' the library, or if I can run anything in my own code to do the equivalent of the above?

[RobQuincey-DC]

I've made a branch where I have created an exported function called initSetFetchOptionsUpdateCallback containing the setFetchOptionsUpdateCallback code, which means it can be called from other places, in my particular instance, it means I can should be able to call it in my own setup code without having to worry about the bundler removing the default initialization. See diff here - main...RobQuincey-DC:ogc-client:feature-export-setfetchoptions-function - I've not opened a PR for this as I am not sure if this is the right way to go about this, but its a proof of concept at least.

[jahow]

Hmm interesting, good find. I think we can consider a workaround like this one, although I'd like understanding first why that piece of code gets removed by the bundler.

[RobQuincey-DC]

I agree, I don't much like this workaround but its the best I've been able to come up with so far to get round my very specific issue. I'll keep digging into why the bundler is booting out that code and see if I can find something more concrete, but my experience with webpack is fairly limited!