Add a command for stopping all LSP clients

autoload/ale/definition.vim

@@ -19,6 +19,10 @@ function! ale#definition#Execute(expr) abort
     execute a:expr
 endfunction
 
+function! ale#definition#ClearLSPData() abort
+    let s:go_to_definition_map = {}
+endfunction
+
 function! ale#definition#Open(options, filename, line, column) abort
     if a:options.open_in_tab
         call ale#definition#Execute('tabedit ' . fnameescape(a:filename))

autoload/ale/engine.vim

@@ -76,6 +76,11 @@ function! ale#engine#InitBufferInfo(buffer) abort
     return 0
 endfunction
 
+" Clear LSP linter data for the linting engine.
+function! ale#engine#ClearLSPData() abort
+    let s:lsp_linter_map = {}
+endfunction
+
 " This function is documented and part of the public API.
 "
 " Return 1 if ALE is busy checking a given buffer
@@ -144,7 +149,7 @@ function! s:GatherOutput(job_id, line) abort
     endif
 endfunction
 
-function! s:HandleLoclist(linter_name, buffer, loclist) abort
+function! ale#engine#HandleLoclist(linter_name, buffer, loclist) abort
     let l:info = get(g:ale_buffer_info, a:buffer, {})
 
     if empty(l:info)
@@ -223,7 +228,7 @@ function! s:HandleExit(job_id, exit_code) abort
 
     let l:loclist = ale#util#GetFunction(l:linter.callback)(l:buffer, l:output)
 
-    call s:HandleLoclist(l:linter.name, l:buffer, l:loclist)
+    call ale#engine#HandleLoclist(l:linter.name, l:buffer, l:loclist)
 endfunction
 
 function! s:HandleLSPDiagnostics(conn_id, response) abort
@@ -237,7 +242,7 @@ function! s:HandleLSPDiagnostics(conn_id, response) abort
 
     let l:loclist = ale#lsp#response#ReadDiagnostics(a:response)
 
-    call s:HandleLoclist(l:linter_name, l:buffer, l:loclist)
+    call ale#engine#HandleLoclist(l:linter_name, l:buffer, l:loclist)
 endfunction
 
 function! s:HandleTSServerDiagnostics(response, error_type) abort
@@ -262,7 +267,7 @@ function! s:HandleTSServerDiagnostics(response, error_type) abort
     let l:loclist = get(l:info, 'semantic_loclist', [])
     \   + get(l:info, 'syntax_loclist', [])
 
-    call s:HandleLoclist('tsserver', l:buffer, l:loclist)
+    call ale#engine#HandleLoclist('tsserver', l:buffer, l:loclist)
 endfunction
 
 function! s:HandleLSPErrorMessage(error_message) abort

autoload/ale/lsp.vim

@@ -325,6 +325,20 @@ function! ale#lsp#ConnectToAddress(address, project_root, callback) abort
     return 1
 endfunction
 
+" Stop all LSP connections, closing all jobs and channels, and removing any
+" queued messages.
+function! ale#lsp#StopAll() abort
+    for l:conn in s:connections
+        if has_key(l:conn, 'channel')
+            call ch_close(l:conn.channel)
+        else
+            call ale#job#Stop(l:conn.id)
+        endif
+    endfor
+
+    let s:connections = []
+endfunction
+
 function! s:SendMessageData(conn, data) abort
     if has_key(a:conn, 'executable')
         call ale#job#SendRaw(a:conn.id, a:data)

autoload/ale/lsp/reset.vim

@@ -0,0 +1,25 @@
+" Stop all LSPs and remove all of the data for them.
+function! ale#lsp#reset#StopAllLSPs() abort
+    call ale#lsp#StopAll()
+
+    if exists('*ale#definition#ClearLSPData')
+        " Clear the mapping for connections, etc.
+        call ale#definition#ClearLSPData()
+    endif
+
+    if exists('*ale#engine#ClearLSPData')
+        " Clear the mapping for connections, etc.
+        call ale#engine#ClearLSPData()
+
+        " Remove the problems for all of the LSP linters in every buffer.
+        for l:buffer_string in keys(g:ale_buffer_info)
+            let l:buffer = str2nr(l:buffer_string)
+
+            for l:linter in ale#linter#Get(getbufvar(l:buffer, '&filetype'))
+                if !empty(l:linter.lsp)
+                    call ale#engine#HandleLoclist(l:linter.name, l:buffer, [])
+                endif
+            endfor
+        endfor
+    endif
+endfunction