clear LSP clients

[willthbill]

I might be interested in clearing LSP clients, so that old LSP clients does not keep on running in the background after opening a new directory.
I have implemented the simplest fix on branch clear-lsp-clients, but it seems to give session-related problems (see b58b760)
More specifically regarding auto-session if I stop all LSP clients and then restores a session that was saved while an LSP client was active I get an error.

Error detected while processing CursorMoved Autocommands for "<buffer=7>":
method textDocument/documentHighlight is not supported by any of the servers registered for the current buffer

I have the following setup of opener.nvim, which means that LSP clients are stopped and they immediatly after RestoreSession is called.

require("opener").setup {
     pre_open = function()
        vim.cmd "SaveSession"
    end,
    post_open = function(dir)
        local Lib = require "auto-session-library"
        Lib.conf.last_loaded_session = nil
        vim.cmd "RestoreSession"
    end,
}

This is of course due to no LSP client being active at the time of restoring, but is that really necessary to restore a session?

[willthbill]

@rmagatti Do you have any thoughts on this. Could it be a potential bug in auto-session? Or am I missing a simple fix. I don't understand all the technical details of how sessions work.

[rmagatti]

This is more because the autocmd for CursorMoved is still registered and it gets triggered, but you've stopped the clients. It's kind of unrelated to session saving altogether, it's just that by killing the lsp clients yourself but not unregistering whatever autocmds use the clients you end up running into this.

Also I thought lsp clients wouldn't keep running in the background if there is no buffer for them to attach to, but idk if that's accurate.

[willthbill]

That makes sense.
Unfortunately it seems that automatically shutting down clients/servers (idk what to call them, clients that communicate with a server) is on the 0.9 todos neovim/neovim#14430