Refactor LSP custom request handling

autoload/ale/lsp.vim

@@ -5,9 +5,6 @@
 let s:connections = get(s:, 'connections', {})
 let g:ale_lsp_next_message_id = 1
 
-" A Dictionary to track one-shot callbacks for custom LSP requests
-let s:custom_callbacks = get(s:, 'custom_callbacks', {})
-
 " Given an id, which can be an executable or address, and a project path,
 " create a new connection if needed. Return a unique ID for the connection.
 function! ale#lsp#Register(executable_or_address, project, init_options) abort
@@ -299,19 +296,10 @@ function! ale#lsp#HandleMessage(conn_id, message) abort
     " responses.
     if l:conn.initialized
         for l:response in l:response_list
-            if has_key(l:response, 'id') && has_key(s:custom_callbacks, l:response.id)
-                " Response to a custom request, call the registered one-shot handler.
-                try
-                    call s:custom_callbacks[l:response.id](l:response)
-                finally
-                    call remove(s:custom_callbacks, l:response.id)
-                endtry
-            else
             " Call all of the registered handlers with the response.
             for l:Callback in l:conn.callback_list
                 call ale#util#GetFunction(l:Callback)(a:conn_id, l:response)
             endfor
-            endif
         endfor
     endif
 endfunction
@@ -537,18 +525,6 @@ function! ale#lsp#Send(conn_id, message) abort
     return l:id == 0 ? -1 : l:id
 endfunction
 
-" Send a custom request to an LSP server.
-" The given callback is called on response.
-function! ale#lsp#SendCustomRequest(conn_id, message, Callback) abort
-    let l:id = ale#lsp#Send(a:conn_id, a:message)
-
-    if l:id > 0
-        let s:custom_callbacks[l:id] = a:Callback
-    endif
-
-    return l:id
-endfunction
-
 " Notify LSP servers or tsserver if a document is opened, if needed.
 " If a document is opened, 1 will be returned, otherwise 0 will be returned.
 function! ale#lsp#OpenDocument(conn_id, buffer, language_id) abort

autoload/ale/lsp_linter.vim

@@ -8,6 +8,9 @@ if !has_key(s:, 'lsp_linter_map')
     let s:lsp_linter_map = {}
 endif
 
+" A Dictionary to track one-shot callbacks for custom LSP requests
+let s:custom_callbacks_map = get(s:, 'custom_callbacks_map', {})
+
 " Check if diagnostics for a particular linter should be ignored.
 function! s:ShouldIgnore(buffer, linter_name) abort
     " Ignore all diagnostics if LSP integration is disabled.
@@ -407,6 +410,7 @@ endfunction
 " Clear LSP linter data for the linting engine.
 function! ale#lsp_linter#ClearLSPData() abort
     let s:lsp_linter_map = {}
+    let s:custom_callbacks_map = {}
 endfunction
 
 " Just for tests.
@@ -414,6 +418,24 @@ function! ale#lsp_linter#SetLSPLinterMap(replacement_map) abort
     let s:lsp_linter_map = a:replacement_map
 endfunction
 
+function! s:HandleLSPResponseToCustomRequests(conn_id, response) abort
+    if has_key(a:response, 'id')
+    \&& has_key(s:custom_callbacks_map, a:response.id)
+        let l:Callback = remove(s:custom_callbacks_map, a:response.id)
+        call l:Callback(a:response)
+    endif
+endfunction
+
+function! s:OnReadyForCustomRequests(message, Callback, linter, lsp_details) abort
+    let l:id = a:lsp_details.connection_id
+    let l:Callback = function('s:HandleLSPResponseToCustomRequests')
+
+    call ale#lsp#RegisterCallback(l:id, l:Callback)
+
+    let l:request_id = ale#lsp#Send(l:id, a:message)
+    let s:custom_callbacks_map[l:request_id] = a:Callback
+endfunction
+
 " Send a custom request to an LSP linter.
 function! ale#lsp_linter#SendRequest(buffer, linter_name, method, parameters, Callback) abort
     let l:filetype = ale#linter#ResolveFiletype(getbufvar(a:buffer, '&filetype'))
@@ -425,17 +447,13 @@ function! ale#lsp_linter#SendRequest(buffer, linter_name, method, parameters, Ca
     endif
 
     let l:linter = l:linter_list[0]
-    let l:executable_or_address = ''
 
-    if l:linter.lsp is# 'socket'
+    if empty(l:linter.lsp)
-        let l:executable_or_address = ale#linter#GetAddress(a:buffer, l:linter)
+        throw 'Linter "' . a:linter_name . '" does not support LSP!'
-    else
-        let l:executable_or_address = ale#linter#GetExecutable(a:buffer, l:linter)
     endif
 
-    let l:root = ale#util#GetFunction(l:linter.project_root)(a:buffer)
-    let l:conn_id = l:executable_or_address . ':' . l:root
     let l:message = [0, a:method, a:parameters]
+    let l:Callback = function('s:OnReadyForCustomRequests', [l:message, a:Callback])
 
-    return ale#lsp#SendCustomRequest(l:conn_id, l:message, a:Callback) == 0
+    return ale#lsp_linter#StartLSP(a:buffer, l:linter, l:Callback)
 endfunction

doc/ale.txt

@@ -3205,9 +3205,6 @@ ale#lsp_linter#SendRequest(buffer, linter_name, method, parameters, Callback)
   request is received, and takes as unique argument a dictionary representing
   the response to the request obtained from the server.
 
-  The function returns zero if the request is succesfully sent, non-zero
-  otherwise.
-
 
 ale#other_source#ShowResults(buffer, linter_name, loclist)
                                                *ale#other_source#ShowResults()*

test/lsp/test_lsp_custom_request.vader

@@ -7,13 +7,15 @@ Before:
   let g:callback_result = 0
   let g:conn_id = -1
   let g:executable = 'ccls'
+  let g:executable_or_address = ''
   let g:linter_name = 'ccls'
   let g:magic_number = 42
-  let g:message = -1
+  let g:message_list = []
   let g:message_id = 1
   let g:method = '$ccls/call'
   let g:parameters = {}
-  let g:project = '/project/root'
+  let g:project_root = '/project/root'
+  let g:response = ''
   let g:return_value = -1
 
   let g:linter_list = [{
@@ -21,7 +23,7 @@ Before:
   \   'lint_file': 0,
   \   'language': 'cpp',
   \   'name': g:linter_name,
-  \   'project_root': {b -> g:project},
+  \   'project_root': {b -> g:project_root},
   \   'aliases': [],
   \   'language_callback': {b -> 'cpp'},
   \   'read_buffer': 1,
@@ -34,10 +36,20 @@ Before:
     return 'Content-Length: ' . strlen(l:body) . "\r\n\r\n" . l:body
   endfunction
 
-  " Register the server with given executable or address
+  " Replace the StartLSP function to mock an LSP linter
-  function! InitServer(executable_or_address) abort
+  function! ale#lsp_linter#StartLSP(buffer, linter, Callback) abort
-    let g:conn_id = ale#lsp#Register(a:executable_or_address, g:project, {})
+    let g:conn_id = ale#lsp#Register(g:executable_or_address, g:project_root, {})
+    call ale#lsp#MarkDocumentAsOpen(g:conn_id, a:buffer)
     call ale#lsp#HandleMessage(g:conn_id, Encode({'method': 'initialize'}))
+
+    let l:details = {
+    \ 'command': g:executable,
+    \ 'buffer': a:buffer,
+    \ 'connection_id': g:conn_id,
+    \ 'project_root': g:project_root,
+    \}
+
+    call ale#lsp_linter#OnInit(a:linter, l:details, a:Callback)
   endfunction
 
   " Dummy callback
@@ -52,25 +64,29 @@ Before:
 
   " Replace the Send function to mock an LSP linter
   function! ale#lsp#Send(conn_id, message) abort
-    let g:message = a:message
+    call add(g:message_list, a:message)
     return g:message_id
   endfunction
 
   " Code for a test case
   function! TestCase() abort
     " Test sending a custom request
-    let g:return_value = ale#lsp_linter#SendRequest(bufnr('%'), g:linter_name, g:method, g:parameters, function('Callback'))
+    let g:return_value = ale#lsp_linter#SendRequest(
+    \  bufnr('%'),
+    \  g:linter_name,
+    \  g:method,
+    \  g:parameters,
+    \  function('Callback'))
 
-    AssertEqual
+    Assert index(g:message_list, [0, g:method, g:parameters]) >= 0
-    \ 0,
-    \ g:return_value
-
-    AssertEqual
-    \ [0, g:method, g:parameters],
-    \ g:message
 
     " Mock an incoming response to the request
-    call ale#lsp#HandleMessage(g:conn_id, Encode({'id': g:message_id, 'jsonrpc': '2.0', 'result': {'value': g:magic_number}}))
+    let g:response = Encode({
+    \  'id': g:message_id,
+    \  'jsonrpc': '2.0',
+    \  'result': {'value': g:magic_number}
+    \ })
+    call ale#lsp#HandleMessage(g:conn_id, g:response)
 
     AssertEqual
     \ g:magic_number,
@@ -87,15 +103,15 @@ After:
   unlet! g:executable
   unlet! g:linter_name
   unlet! g:magic_number
-  unlet! g:message
+  unlet! g:message_list
   unlet! g:message_id
   unlet! g:method
   unlet! g:parameters
-  unlet! g:project
+  unlet! g:project_root
+  unlet! g:response
   unlet! g:return_value
 
   delfunction Encode
-  delfunction InitServer
   delfunction Callback
   delfunction TestCase
 
@@ -105,7 +121,7 @@ After:
 
 Given cpp(Empty cpp file):
 Execute(Test custom request to server identified by executable):
-  call InitServer(g:executable)
+  let g:executable_or_address = g:executable
   let g:linter_list[0].executable = {b -> g:executable}
   let g:linter_list[0].lsp = 'stdio'
 
@@ -113,7 +129,7 @@ Execute(Test custom request to server identified by executable):
 
 Given cpp(Empty cpp file):
 Execute(Test custom request to server identified by address):
-  call InitServer(g:address)
+  let g:executable_or_address = g:address
   let g:linter_list[0].address = {b -> g:address}
   let g:linter_list[0].lsp = 'socket'