WebAssembly streaming API fails with inspector

[peter-jerry-ye]

• Steps to reproduce by slightly altering the example of https://docs.deno.com/runtime/manual/runtime/webassembly/using_streaming_wasm

  • Run curl https://wpt.live/wasm/incrementer.wasm -o incrementer.wasm to get the wasm file
  • Create a file named "index.ts" with following contents:

  const { instance, module } = await WebAssembly.instantiateStreaming(
    fetch(new URL("./incrementer.wasm", import.meta.url)),
  );
  const increment = instance.exports.increment as (input: number) => number;
  console.log(increment(41));

  • Run deno run --inspect-brk --allow-read ./index.ts
  • Visit chrome://inspect to connect to the debugger and execute the program

• Expected output

  • Log 42 on the console

• Actual output

error: Uncaught (in promise) TypeError: WebAssembly.compile(): Argument 0 must be a buffer source
    at eventLoopTick (ext:core/01_core.js:178:11)

Also tested with VSCode debugger

• Version:
  • Deno 1.38.4
  • Chrome 120.0.6099.71
  • VSCode 1.84.2
  • macOS Sonoma 14.0

[mcgear]

Any news on this? I am getting the same trying to use @deno/graph wasm in a solution.

[Hajime-san]

related denoland/vscode_deno#708

[peter-jerry-ye]

FYI, a workaround for this is:

const response = await fetch(new URL("./incrementer.wasm", import.meta.url));
const buffer = await response.arrayBuffer();
const { instance, module } = await WebAssembly.instantiateStreaming(
  buffer
);
const increment = instance.exports.increment as (input: number) => number;
console.log(increment(41));

There must be a mismatch with the type check or implementation

[0f-0b]

Could this issue be caused by the --wasm-test-streaming V8 flag?

[peter-jerry-ye]

Could this issue be caused by the --wasm-test-streaming V8 flag?

I'm not quite sure. I tried with --no-wasm-test-streaming and nothing changed. It could be me using it the wrong way.