posix socket api to websocket does not work with any version of node's ws but works in chrome 92.

[themighty1]

using latest emsdk

I compiled my project with ... -s WEBSOCKET_URL=ws://192.168.1.63:12345 -s WEBSOCKET_DEBUG=1 -s SOCKET_DEBUG=1 -o project.html

I launched a local ws server on port 12345 to see if any ws connection attempts are made.

I installed node's ws on client side. (I tried every version of ws with npm install ws@1 all the way to ws@7 to rule out that ws version is at fault)

node version is v16.5.0

when I launch the wasm client with
node project.js, I get on the node console

connect: ws://192.168.1.63:12345, binary
websocket adding peer: 192.168.1.63:12345

but nothing is logged on the ws server console.

When I load project.html in Chrome 92, I immediately see connection attempts on the server console.

I did read somewhere (can't find now where that node's ws version must be 2, so I tried all ws versions in the 2.0.0-2.3.1 range - to no avail)

I really hope I'm missing something simple here. I would appreciate any pointers.

[sbc100]

It looks like we have at least one test for nodejs + websockets:

emscripten/tests/test_sockets.py

Line 408 in 5af6a11

def test_nodejs_sockets_echo(self):

Does that test run for you: ./tests/runner sockets.test_nodejs_sockets_echo --browser=0 ?

[sbc100]

Given that there is only a single test for this maybe its not surprising its not fully working.

Out of interest, why would we want to write websocket using code that runs under node? Wouldn't we just expose the node TCP/UDP APIs directly and avoid the whole websocket server thing?

[themighty1]

@sbc100 , hi, thanks for your input,
./tests/runner sockets.test_nodejs_sockets_echo --browser=0
returned OK.

emscripten does not talk to TCP directly because if the code runs in the browser, there is no TCP, only websocket.

[sbc100]

Right but you are talking about running under node, right? Where sockets do exist, right? I'm just wondering if you you have a need to run websockets under node for some reason or if you are just interested in testing? Or something else maybe?

[themighty1]

Actually, my end goal is to run it in the browser. It is just faster to debug in node. So, node is an intermediate step.

[sbc100]

I see, so it mostly for debugging/testing purposes. I agree that is useful goal. As you can see right now most of our testing is of websockets (aside from the one single test sockets.test_nodejs_sockets_echo is done in the browser rather than under node which might explain why there might be bugs running under node.

Can you figure out why that sockets.test_nodejs_sockets_echo test works but your code does not? Are you trying to do something more complex/different?

[stale]

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