LspStopServer: Stop all and stop specific

It is convenient to be able to stop all LSP servers, regardless of the
currently active buffer.

Also, it seems confusing that when a server name is specified, it is
only stopped if it is also one handling the current buffer type.  I
would imagine it is quite rare to have more than one server handing a
specific buffer type.  And if one explicitly specified a name, it seems
reasonable to stop this particular server, regardless of the currently
active buffer.

autoload/lsp.vim

@@ -95,6 +95,10 @@ function! lsp#get_server_names() abort
     return keys(s:servers)
 endfunction
 
+function! lsp#is_valid_server_name(name) abort
+    return has_key(s:servers, a:name)
+endfunction
+
 function! lsp#get_server_info(server_name) abort
     return get(get(s:servers, a:server_name, {}), 'server_info', {})
 endfunction
@@ -128,6 +132,19 @@ function! s:server_status(server_name) abort
     return 'not running'
 endfunction
 
+function! lsp#is_server_running(name) abort
+    if !has_key(s:servers, a:name)
+      return 0
+    endif
+
+    let l:server = s:servers[a:name]
+
+    return has_key(l:server, 'init_result')
+        \ && !has_key(l:server, 'exited')
+        \ && !has_key(l:server, 'init_callbacks')
+        \ && !has_key(l:server, 'failed')
+endfunction
+
 " Returns the current status of all servers (if called with no arguments) or
 " the given server (if given an argument). Can be one of "unknown server",
 " "exited", "starting", "failed", "running", "not running"
@@ -1329,6 +1346,13 @@ function! lsp#server_complete(lead, line, pos) abort
     return filter(sort(keys(s:servers)), 'stridx(v:val, a:lead)==0 && has_key(s:servers[v:val], "init_result")')
 endfunction
 
+function! lsp#server_complete_running(lead, line, pos) abort
+    let l:all_servers = sort(keys(s:servers))
+    return filter(l:all_servers, {idx, name ->
+        \ stridx(name, a:lead) == 0 && lsp#is_server_running(name)
+        \ })
+endfunction
+
 function! lsp#_new_command() abort
     let s:last_command_id += 1
     call lsp#stream(1, { 'command': 1 })

autoload/lsp/ui/vim.vim

@@ -127,17 +127,79 @@ function! lsp#ui#vim#rename() abort
     call s:rename(l:server, input('new name: ', expand('<cword>')), lsp#get_position())
 endfunction
 
-function! lsp#ui#vim#stop_server(...) abort
-    let l:name = get(a:000, 0, '')
-    for l:server in lsp#get_allowed_servers()
-        if !empty(l:name) && l:server != l:name
+function! s:stop_all_servers() abort
+    for l:server in lsp#get_server_names()
+        if !lsp#is_server_running(l:server)
             continue
         endif
+
         echo 'Stopping' l:server 'server ...'
         call lsp#stop_server(l:server)
     endfor
 endfunction
 
+function! s:stop_named_server(name) abort
+    if !lsp#is_valid_server_name(a:name)
+        call lsp#utils#warning('No LSP server named ' . a:name)
+        return
+    endif
+
+    if lsp#is_server_running(a:name)
+        echo 'Stopping' a:name 'server ...'
+        call lsp#stop_server(a:name)
+    else
+        call lsp#utils#warning(
+            \ 'Server ' . a:name . ' is not running: '
+            \ . lsp#get_server_status(a:name)
+            \ )
+    endif
+endfunction
+
+function! s:stop_buffer_servers() abort
+    let l:servers = lsp#get_allowed_servers()
+    let l:servers =
+        \ filter(l:servers, {idx, name -> lsp#is_server_running(name)})
+
+    if empty(l:servers)
+        call lsp#utils#warning('No active LSP servers for the current buffer')
+        return
+    endif
+
+    for l:server in l:servers
+        echo 'Stopping' l:server 'server ...'
+        call lsp#stop_server(l:server)
+    endfor
+endfunction
+
+function! lsp#ui#vim#stop_server(stop_all, ...) abort
+    echo a:000
+    if a:0 != 0 && a:0 != 1
+        call lsp#utils#error(
+            \ 'lsp#ui#vim#stop_server(): expected 1 optional "name" argument.'
+            \ . ' Got: "' . join(a:000, '", "') . '".'
+        return
+    endif
+    let l:stop_all = a:stop_all == '!'
+    let l:name = get(a:000, 0, '')
+
+    if l:stop_all
+        if !empty(l:name)
+            call lsp#utils#error(
+                \ '"!" stops all servers: name is ignored: ' . l:name)
+        endif
+
+        call s:stop_all_servers()
+        return
+    endif
+
+    if !empty(l:name)
+        call s:stop_named_server(l:name)
+        return
+    endif
+
+    call s:stop_buffer_servers()
+endfunction
+
 function! lsp#ui#vim#workspace_symbol(query) abort
     let l:servers = filter(lsp#get_allowed_servers(), 'lsp#capabilities#has_workspace_symbol_provider(v:val)')
     let l:command_id = lsp#_new_command()

doc/vim-lsp.txt

@@ -1909,17 +1909,28 @@ Prints the status of all registered servers. Use `:verbose LspStatus` to
 additionally show each server's workspace_config.
 See also |vim-lsp-healthcheck|.
 
-LspStopServer [name]                                         *:LspStopServer*
+LspStopServer[!] [name]                                      *:LspStopServer*
 
-If 'name' is not specified, then all active servers that handle files matching
-the current buffer type are stopped.  This is often what you want.  For
-example, if you have multiple files of different types open, `LspStopServer`
-will only stop the server for the current buffer.
+:LspStopServer
 
-When 'name' is provided, it acts as an additional restriction, only stopping
-server that handles the current buffer type, if it also matches the specifie
-name.  'name' value is compred to the 'name' property in the
-|lsp#register_server()| call.
+Stops all active servers that handle files matching the current buffer type
+are stopped.  This is often what you want.  For example, if you have multiple
+files of different types open, `LspStopServer` will only stop the server for
+the current buffer.  Shows an error if there are no active LSP servers for the
+current buffer.
+
+:LspStopServer!
+
+Stops all active servers, regardless of the current buffer.  Shows a message
+for every stopped server.
+
+:LspStopServer name
+
+Stops a server named 'name', comparing the provided ID with the value of the
+the 'name' property in the |lsp#register_server()| call.  Shows an error if
+'name' does not match a defined and currently running server.
+
+Completion should list only currently running servers for the 'name' argument.
 
 ==============================================================================
 Autocommands                                          *vim-lsp-autocommands*

plugin/lsp.vim

@@ -152,7 +152,7 @@ command! LspPeekImplementation call lsp#ui#vim#implementation(1)
 command! -nargs=0 LspStatus call lsp#print_server_status()
 command! LspNextReference call lsp#internal#document_highlight#jump(+1)
 command! LspPreviousReference call lsp#internal#document_highlight#jump(-1)
-command! -nargs=? -complete=customlist,lsp#server_complete LspStopServer call lsp#ui#vim#stop_server(<f-args>)
+command! -nargs=? -bang -complete=customlist,lsp#server_complete_running LspStopServer call lsp#ui#vim#stop_server("<bang>", <f-args>)
 command! -nargs=? -complete=customlist,lsp#utils#empty_complete LspSignatureHelp call lsp#ui#vim#signature_help#get_signature_help_under_cursor()
 command! LspDocumentFold call lsp#ui#vim#folding#fold(0)
 command! LspDocumentFoldSync call lsp#ui#vim#folding#fold(1)