Calling client.stop() may produce error in output panel

[renkun-ken]

In REditorSupport/vscode-r-lsp#59, the language client works with a spawned process that runs the language server, and they communicate with each other via TCP socket.

The usage is, when the first untitled document is created with r language, then a new language server is started. All untitled documents share the same language client/server. If all untitled documents are closed, then shutdown the language server by calling client.stop().

However, it usually (randomly) causes the following error in the output channel, which shift the view of the side panel to the error logging. This is quite annoying.

Output channel:

R Language Server (391970) started
[Error - 4:29:24 PM] Connection to server is erroring. Shutting down server.
[Error - 4:29:24 PM] Connection to server is erroring. Shutting down server.
R Language Server (391970) exited with exit code 0

Extension debug console

Error: Unexpected SIGPIPE
	at process.<anonymous> (/usr/share/code/resources/app/out/bootstrap.js:5:284)
	at process.emit (events.js:203:13)

This error seems to come from the language client but I'm not sure if there's a way to handle this error somewhere?

[dbaeumer]

Can you enable tracing so that we can see what messages are causing this?

[renkun-ken]

Here's a log I created with tracing enabled and the problem reproduced:

r-lsp.log

Not sure if it is useful as I find little relevant information:

[Trace - 9:01:23 PM] Received response 'shutdown - (1)' in 229ms.
Result: []


[Trace - 9:01:23 PM] Sending notification 'exit'.
No parameters provided.


[Error - 9:01:23 PM] Connection to server is erroring. Shutting down server.
[Error - 9:01:23 PM] Connection to server is erroring. Shutting down server.

As the file is closed, client.stop() is called then the error occurs.

[dbaeumer]

That is strange since the client should not send anything after the exit. So unclear why it is erroring. I will have a look.

[dbaeumer]

OK. I looked through the doc and code and IMO the problem is that the connections needs to end their write streams. I have added code to the node server and the client to handle this poperly.

This being said server implemented in their own language need to do the same.

[renkun-ken]

Thanks!