g:fsharp#languageserver_command is not defined after installing Ionide-vim

[panesofglass]

Describe the bug g:fsharp#languageserver_command is not defined after installing Ionide-vim.

To Reproduce Steps to reproduce the behaviour:

1. Follow instructions to install Ionide-vim
2. Edit any file with nvim .
3. See error while nvim opens

Expected behaviour Correctly load a pre-configured variable named g:fsharp#languageserver_command to issue commands to FSAC.

Screenshots

Error detected while processing /home/ryan/.vim/init.vim:
line   42:
E121: Undefined variable: g:fsharp#languageserver_command
E15: Invalid expression: { 'fsharp': g:fsharp#languageserver_command }

Environment (please complete the following information):

• OS: Ubuntu 18.04
• Ionide version: master
• VSCode version: N/A
• dotnet SDK version: 2.2.402
• mono / .Net Framework version:

[panesofglass]

Looks like the issue could be related to my switch to Vim8's built-in package manager pack/*/start path, the install.fsx places the built package in the wrong place. By changing the path to pack/bundle/start/* in install.fsx, it seems like it should work, but I see the same result.

[cannorin]

I haven't really tested install.fsx so much so it may be not working correctly. I'll investigate it.

[cannorin]

As a workaround for now, you can use Plug or dein.vim and it should work as expected.

[cannorin]

Did you use install.sh for installing?

[panesofglass]

Yes, I used install.sh. I’m not interested in using plug or dein.vim, so I’ll pass for now. Thanks.

[cannorin]

If you've installed to .vim/pack/*/start, it won't work in neovim: try .local/share/nvim/site/pack/*/start instead.

[cannorin]

If not, let me know and I'll set up a new Ubuntu environment and try to figure out why it isn't working.

[giulioungaretti]

@cannorin I have the same issue actually, installing with Plug :D running vim on mac osx! LMK if you'd rather have another issue opened, or just continue here and more importantly if any more details could help you! I'd love to get this working :D

[cannorin]

@giulioungaretti It could be because you added

let g:LanguageClient_serverCommands = {
  \ 'fsharp': g:fsharp#languageserver_command
  \ }

before you installed the plugin by executing :PlugInstall. Adding it after installing should not trigger the error. If it wasn't the case, let me know more details.

[giulioungaretti]

:PlugInstall ✔️

Open vim in ~ get:

Error detected while processing /Users/unga/.vimPlug:
line   23:
E121: Undefined variable: g:fsharp#languageserver_command
Press ENTER or type command to continue

Open a .fs file:

Error detected while processing /Users/unga/.vim/plugged/Ionide-vim/ftplugin/fsharp.vim:
line   12:
FSAC not found. :FSharpUpdateFSAC to download.

Run said command:

E492: Not an editor command: FSharpUpdateFSAC 

Which makes me think it could be related to some PATH issues ?

[cannorin]

Ah, my bad. That's because I placed the existence-checking code before defining commands: https://github.com/ionide/Ionide-vim/blob/master/ftplugin/fsharp.vim#L11

As a workaround, could you try doing :call fsharp#updateFSAC() and see what happens?

[panesofglass]

It's still not working for me. :( I'll continue to try again every so often.

[cannorin]

@panesofglass I'll reproduce your environment and try to find out why it isn't working. Could you provide me the location of Ionide-vim and your .vimrc?

[cannorin]

@giulioungaretti https://github.com/ionide/Ionide-vim/commit/5f4f194bc1d2721156fe0b861371360df40ed527 addressed the problem :FSharpUpdateFSAC is not available. If you have not tried the workaround above, you can instead upgrade Ionide-vim to the latest. I suspect that autoload/fsharp.vim is not correctly loaded, so if my guess is correct it will give you a different error message.

[panesofglass]

@cannorin thank you! On Windows, I'm using ~\AppData\Local\nvim with an init.vim in that folder. On Linux, I'm using ~/.config/nvim with init.vim in that folder. I'm storing my plugins using ~/*/nvim/pack/bundle/start. You can access my vimfiles where I'm trying to use Ionide-vim here. (I should have shared that sooner, come to think of it.)

[cannorin]

@panesofglass

1. You are using the master branch of LanguageClient-neovim which is very outdated and cannot be used. Switch to the next branch and run install.sh.
2. I didn't know that plugins are loaded after vimrc/init.vim unless manually sourced (which most plugin managers do), which is the source of this problem. I should restructure the settings flow in order to fix this.

[cannorin]

@giulioungaretti @panesofglass I just created issue-8_languageserver-command-not-defined branch and applied the fix (hopefully) to it. Can you switch to that branch and try it out?

The languageserver configuration is now done automatically and

let g:LanguageClient_serverCommands = {
  \ 'fsharp': g:fsharp#languageserver_command
  \ }

in vimrc/init.vim is not needed anymore.

[giulioungaretti]

@cannorin it works wonderfully with that branch! Tested on wsl2 + mac osx!

[cannorin]

@giulioungaretti Great to hear that!

[panesofglass]

I've updated everything, but I still see the error on both wsl2 and windows. Maybe I missed something?

[cannorin]

@panesofglass Make sure you removed the let g:LanguageClient_serverCommands = ... line from your init.vim as it would be the only source of the "not defined" error.

[panesofglass]

Ah, thanks! I missed that bit. It works great now! By the way, if I wanted to add additional language server commands, would I just not add anything about fsharp?

[cannorin]

Thanks! I'll merge the fix now.

The current implementation of Ionide-vim only adds the F# language server command when editing F# files, so you can just add language server of another languages.

[cannorin]

@panesofglass @giulioungaretti Don't forget to switch back to the master branch (I'll delete the issue branch in few days). Thanks a lot for reporting a bug :joy: