We have an Angular app that has been in production for about a year and everything is working as expected. This week we deployed support for PWA in the app and for the most part it is working as expected.
We did run into 1 issue that I understand, but I am not sure how to approach solving it as I can't find any doc that points me in the right direction....lots of clips that tell me why it's the problem, but not how to go about solving it. The issue we are having is that on some (not all) Samsung mobile devices, our Font-Awesome icons no longer display in the app. When it fails, the browser is pointing to CORS being the culprit. This is not failing on any desktop device we have tried, nor any other mobile device. We are only seeing this on some Samsung devices. I have attached that error here:
In our app, we leverage the FA CDN instead of pulling in a kit or hosting those resources on our server. To do this, the index.html file links to the FA all.css file using the following in the head:
<link rel="stylesheet" href="https://pro.fontawesome.com/releases/v5.15.1/css/all.css" integrity="sha_key_removed" crossorigin="anonymous">
The ngsw-config.json file that configures the FA url looks like the following:
My best guess is that this works fine in non-PWA because of the crossorigin flag that is sent with the link via index.html, but once PWA kicks in, the lack of that flag being pushed over is causing the CORS failure. My guess is most browsers are sending it over anonymously by default and that is why it works in most cases and when it doesn't is because those specific Samsung devices are not requesting it anonymously. My problem is I am not sure the best way to try to solve this as I can't find any documentation about this specific setup.
What I have tried so far:
According the Angular service worker documentation here, CORS must be properly configured on the origin server to handle resources from different domains. I have our domains configured in our FA portal to be valid domains, so I don't think that is the problem here.
Found information about ngsw-bypass here, but the documentation doesn't really talk about how to use that feature and I haven't been able to find anything that does help in this situation.
Contemplated switching FA to either hosted or kit. Hosted would likely work and should be limited work, but comes with the drawback of no longer getting the advantages of caching of the CDN. This is not ideal. The kit option would also likely work, but I'm guessing would require changes to the code. That would also not be ideal.
If anyone has any ideas on where to look/what to do, I would really appreciate it. I have no problem digging and doing the research/trial & error, but my exposure to PWA/service workers is very limited so at a bit of a loss on what to do as all my research so far hasn't helped.
UPDATE: I think I was able to figure out #2 from my list of "what tried". It appears that ngsw-bypass can be set as a query string parameter. After I append ngsw-bypass=true to the end of the url in the service worker config, it appears to bypass the service worker config for that url and use the native way from index.html. This isn't ideal, but does seem to solve the problem. Going to leave this open and hopefully get something better, but will leave this as an answer if I don't find a better way.
