WebAssembly.instantiateStreaming does not work with Response

[hazae41]

hazae41/foras#1

Since Deno 1.3.1, WebAssembly.instanciateStreaming throws the following error when module is an instance of Response (from fetch)

error: Uncaught TypeError: WebAssembly.compile(): Argument 0 must be a buffer source

[lucacasonato]

@caspervonb do we have a test for this?

[caspervonb]

@caspervonb do we have a test for this?

Hmm, apparently I used a buffer source in the test when I enabled that flag 🤔

[hazae41]

@caspervonb Do we need to temporarily disable instantiateStreaming? Or implement it with Response?

Because modules using Response are broken since they check for the existence of instantiateStreaming before

if (WebAssembly.instantiateStreaming) {
  // use instantiateStreaming()
} else {
  // get the buffer then use instantiate()
}

[caspervonb]

Because modules using Response are broken since they check for the existence of instantiateStreaming before

Oh right, that's bad.. uhm, I'll get back to you.

[dsherret]

I'm able to make this work by doing WebAssembly.instantiateStreaming(response.then(r => r.arrayBuffer()) as any) (which I believe is wrong)

[ghost]

Ahh, saw that Deno had WebAssembly.{compileStreaming, instantiateStreaming}, and thought that it would be fun to try to instantiate ~6 wasm files and set up a project. Then some particularly misleading errors appeared :)

In my opinion, If it doesn't work correctly, it should not be exposed at all. Can we get the PR that caused this to be reverted until this is properly sorted out?

[vovacodes]

Hey folks, is there any progress here? I'd like to use Deno for testing my wasm compiled from Rust with wasm-bindgen but unfortunately, due to this issue Deno chokes on it. I don't control the JS wrapper that calls to WebAssembly.instantiateStreaming (that one is generated by wasm-pack) and even though it does feature detection, that one is broken too (#8968), so it's kinda a blocker.

[lucacasonato]

Temporary workaround could be to call delete WebAssembly.instantiateStreaming; before instantiating the wasm-pack code.