Chromium only partially supports WebUSB API in web workers

[skyclouds2001]

Summary

the WebUSB API is not exposed to shared worker and service worker (except for webextension service workers) in chromium, which should be according to the spec

no related browser issue is found

see chromium source code

this can be test using https://worker-playground.glitch.me/

Note: I'm not sure if partial_implementation or impl_url key should be added or not

---

so full chain is:

1. expose to dedicated worker (M70)

   chromium/chromium@841d469
   chromium/chromium@3267532
   chromium/chromium@6ed4277
   https://chromium-review.googlesource.com/c/chromium/src/+/1014196
   https://chromium-review.googlesource.com/c/chromium/src/+/1053063
   https://chromium-review.googlesource.com/c/chromium/src/+/1153222
   https://issues.chromium.org/issues/40573868
   https://issues.chromium.org/issues/40575664
   https://chromestatus.com/feature/5928209916887040

2. expose to webextension service worker (M118)

   chromium/chromium@cf53ee2
   https://chromium-review.googlesource.com/c/chromium/src/+/3894652
   https://issues.chromium.org/issues/40217296
   https://chromestatus.com/feature/5200265459269632

Test results and supporting details

Related issues

[caugner]

Can you please provide more details?

1. The source code link points only to the webusb directory.
2. Can you share the test you used, and did you also test in an older Chrome?

[skyclouds2001]

1. The source code link points only to the webusb directory.

Because all webusb features is under this folder, and list all webuse idl files is awful. And most idl files are in the same expose scope. like https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/modules/webusb/usb.idl.

2. Can you share the test you used

The test is check if the specific interface is exposed to one of the worker scope.

Also, I found I make a mistake, that the feature is also available in WebExtension service workers. see https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/platform/runtime_enabled_features.json5;l=4850

And as #24538 did, I've instead to use a separate worker_support field to store the data (except for WorkerNavigator.usb).

did you also test in an older Chrome?

Not at this moment.