Audio Worklet tests in the CI don't appear to be run (in test_browser)

[cwoffenden]

EDIT: short version, since I think the error is misleading: they're compiling but they're instantly exiting without running.

Testing with the latest Emscripten locally (3.1.74) and seeing the same in the result from CI. Open any of the CI runs and look at the browser tests, e.g.:

https://app.circleci.com/pipelines/github/emscripten-core/emscripten/38495/workflows/353c8dd2-db7a-4691-a83b-c1b8088f8959/jobs/859340

Search for test_audio_worklet and the parameterised tests all have the same 404 error with missing files:

  test_audio_worklet (test_browser.browser) ... cache:INFO: generating system asset: symbol_lists/c9305f6ae33005a7b005afb88a5689b698a1f55c.json... (this will be cached in "/root/cache/symbol_lists/c9305f6ae33005a7b005afb88a5689b698a1f55c.json" for subsequent builds)
cache:INFO:  - ok
127.0.0.1 - - [11/Dec/2024 12:08:43] code 404, message File not found: /root/project/test.aw.js

I noticed this locally, and thought it was just the way my system was set up, then given that I'd seen there was no way the CI was passing tests that should be failing, I dug deeper. The test runner doesn't find test.aw.js and if that is copied (or a link created) then it next fails on test.js.

The tests are all passing though, I'm guessing because the main page opens and exits (interestingly it's only the Audio Worklets missing files, so 14 404s in test_browser's log).

[cwoffenden]

It seems to stem from the change from btest() to btest_exit(). At a guess, I'd say the server was being shut down before the file was served (if I stop the test harness from existing, via various means, there's no error). The error is therefore not the problem, it's just a side effect of the test instantly exiting.