Usage with vtsls produces significant delays.

[KaranAhlawat]

I didn't think I should create a bug report just yet, so here I am opening a Q&A discussion.
I've wanted to try the vtsls language server (https://github.com/yioneko/vtsls) for TS, JS, and {J,T}SX.

I've configured the eglot-server-programs to use the correct command and the correct language ID for this purpose.

However, when using the server, the completions take a significant amount of time to pop up, and there are many micro-stutters while typing. It can take anywhere from 2-3 seconds for the completions to pop up (either with the built in Completions UI or Corfu).

I cannot seem to figure out why. I had previously raised an issue with the vtsls repository here: yioneko/vtsls#49

As can be seen, the completions work fine and fast with Helix and NeoVim.

Any help would be appreciated :)

[joaotavora]

Karan Ahlawat ***@***.***> writes:

I didn't think I should create a bug report just yet, so here I am opening a Q&A discussion.

That's fine. That's exactly what you should do.

As can be seen, the completions work fine and fast with Helix and NeoVim. Any help would be appreciated :)

You can share your Eglot event logs here, use M-x eglot-events buffer. Maybe Eglot is making too many requests? Or not making the right request at the right time? Else I'll need some way to reproduce this locally. You can also, if you know how to, share a dockerfile that I can build and which will contain a language server installation and a project where you reproduce the problem. I can then connect to the docker machine with Emacs via TRAMP (I've learned to do that recently), and hopefully reproduce the sluggishness. João

[narendraj9]

I have experienced this (only the first issue and not the one with completions) as well, mainly with large projects. If there are a large number of messages being exchanged between Emacs and the language server, logging them to the eglot-events-buffer seems to cause significant delays. I wonder why that is the case because the communication with the language server process is already happening with a buffer that Emacs is writing to.

[yioneko]

@KaranAhlawat It's the bug from server. Fixed in vtsls 0.1.14. Please upgrade the server to see if the issue has been resolved.

[KaranAhlawat]

@yioneko Ah okay! Will check in a bit. I didn't open an issue on the vtsls repository yet because I didn't want to have the issue in the incorrect place.

[KaranAhlawat]

The update to the server now works as expected, although I still think it's a little slower than VSCode to popup the completions. But maybe that's just a limitation of tsserver being used outside of VSCode that cannot be overcome. Overall, it's working fine now!

Thank you @yioneko and @joaotavora.

[yioneko]

I still think it's a little slower than VSCode to popup the completions.

That's what I tried to address in yioneko/vtsls#50. You can test it early by build source code (welcome!) or wait for next release.

[KaranAhlawat]

I think we should move this discussion to yioneko/vtsls#52. Would be highly appreciated if someone knowledgeable about Eglot internals could give their input.