Problem using wasm-bindgen-rayon in wasm-bindgen-test

[yuroitaki]

Related to GoogleChromeLabs/wasm-bindgen-rayon#30, I tried to initalise thread pool in my wasm bindgen test with the following:

use wasm_bindgen_futures::{spawn_local, JsFuture};
use wasm_bindgen::prelude::*;
use wasm_bindgen_test::*;

wasm_bindgen_test_configure!(run_in_browser);

#[wasm_bindgen_test]
async fn test() {
   spawn_local(JsFuture::from(init_thread_pool(8)).map(|_| ()));
   ...
}

and run the test with the following

wasm-pack test --firefox --release

but the webworkers don't seem to have been set up correctly (picture below) and my test just hang halfway — if i disable rayon in my code, the test will work

[themighty1]

Since initThreadPool should be called from within the WebWorker, I'd expect this to work

wasm_bindgen_test_configure!(run_in_dedicated_worker);`

#[wasm_bindgen_test]
async fn test() {
   spawn_local(JsFuture::from(init_thread_pool(8)).map(|_| ()));
   ...
}

But even with the above change, my test hang.
I worked around it by modifying the JS code produces by wasm-bindgen-test:

• add await initThreadPool(navigator.hardwareConcurrency); right after the wasm was initialized. i.e. to this line https://github.com/rustwasm/wasm-bindgen/blob/c108c7520a13fa124038b28db6fb759b35576dd4/crates/cli/src/bin/wasm-bindgen-test-runner/server.rs#L108
• also add initThreadPool, to the imports in that file
• use the patched wasm-bindgen-test-runner instead of the system's default one