Path not working on 2.x ws server

[cbratschi]

So far the following code was working fine on 1.1.2:

    const ws       = require('ws');
    const WSServer = ws.Server;

    const wss = new WSServer({
        server: server,
        path: absPath,

        //do not use compression (slow & memory overhead)
        perMessageDeflate: false
    });

It uses a path and express connection. If the path is removed connections are established.

On 2.x the client just returns:

Error: unexpected server response (400)

It seems the path is not recognized and therefore the connection never being upgraded.

[lpinca]

The value of the path option and the pathname of the connection URL must match.

[cbratschi]

Somehow this longer works on 2.x. Could be something else but if I remove the path the client gets a response. Any ideas?

A different thing I discovered: the latest bufferutil and utf-8-validate modules are not compatible with ws 2.x. Which versions are exactly compatible?

[lpinca]

If you remove the path option, path validation is not run so connection is always established unless there is another way to close it like verifyClient. Can you reduce the issue to a reproducible example?

ws@>=2.0.2 is compatible with all versions of bufferutil and utf-8-validate. ws@<2.0.2 only works with bufferutil@1 and utf-8-validate@<=2.

[lpinca]

In ws@1 the connection was not closed when path validation failed but this is a bug as the request hangs in this case as it never receives a response.

In ws@2 when path validation fails the connection is correctly closed so I think this explains why you see a different behavior between the two versions.

[cbratschi]

Well, I am registering several paths for the express based server. In my case the connection should stay open and be passed to the next ws handler until the path matches. If there is no match express should return a 404 error and close the connection.

So the shouldHandle() call should be done first before doing any further checks which could cause an abortConnection() call.

[lpinca]

Express does not handle upgrade (WebSocket) requests so it will never answer with a 404 to an upgrade request. The Node.js HTTP server emits a 'request' event for non upgrade requests and an 'upgrade' event for upgrade requests. The express handler/router is only used when the 'request' event is emitted.

Hope this makes sense.

[cbratschi]

I see.

If several paths are registered then the connection should only be closed if no matching path was found.

[lpinca]

You can register only a single path in the WebSocket server.

[cbratschi]

The main problem is that we are using several WebSocket servers with different paths but the same express server instance. This was working fine with ws 1.x. Now the first WebSocket server closes the connection if the path would match the path of the registered second WebSocket server. This is a crucial feature because we extend express to allow ws routes which register a WebSocket server using the route's path.

[lpinca]

The main problem is that we are using several WebSocket servers with different paths but the same express server instance.

You didn't say anything about this! Take a look a this comment on how to make this work with ws@2.

[cbratschi]

Thanks for the link. I refactored my code and now everything works again.

[lpinca]

Awesome.