WebSocketStream reading not reliable

[Officialstrike]

Issue Details

• Deno Version:
  • deno 1.19.3 (release, x86_64-pc-windows-msvc)
  • v8 9.9.115.8
  • typescript 4.5.2
• Operating System:
  • Windows 10 21H1

Expected Behavior

While using async/await there should never be an error claiming module eval is still pending.

Actual Behavior

While using async/await, it will return a module eval error after a while error: Module evaluation is still pending but there are no pending ops or dynamic imports. This situation is often caused by unresolved promises.

To Reproduce

• Copy the Async/await code
• run the file using $ deno run --unstable --allow-net <file name here>
• Wait a couple of seconds, and then it will produce an error.

[lucacasonato]

In the .then based code, you are creating an infinite amount of promises by calling reader.read inside of an infinite loop. You never pause to let the networking do anything, you just create a promise, then jump back to the start of the loop, then create another promise etc.

The async/await based code not working is an actual bug in Deno. cc @crowlKats

[Officialstrike]

In the .then based code, you are creating an infinite amount of promises by calling reader.read inside of an infinite loop. You never pause to let the networking do anything, you just create a promise, then jump back to the start of the loop, then create another promise etc.

The async/await based code not working is an actual bug in Deno. cc @crowlKats

Ahh! you've beaten me to it! I was taking shower and then I realized it, was going to update the issue but you've beaten me to the punch.

[Officialstrike]

After debugging in the WebSocket stream file, it seems to lie somewhere at the pull function, specifically when a ping happens. now I implemented my own patch, (hold on cuz it's really dumb). I added controller.enqueue("ping") under 02_websocketstream.js#L272. Now under my own file using reader, I get the value "ping" and I respond with a generic json object just writing await writer.write(JSON.stringify({ type: "ping" }));. Maybe sending a message is keeping the socket alive?

[Officialstrike]

Update: seems like just doing controller.enqueue(); 02_websocketstream.js#L272 alone fixes it.

[Officialstrike]

Update, using the same code with the patch applied above I'm getting this error: error: Uncaught (in promise) Error: IO error: unexpected end of file at Object.pull (deno:ext/websocket/02_websocketstream.js:283:35)

[Officialstrike]

Fixed per #15235