Check LSP capabilities before using them

test/lsp/test_did_save_event.vader

@@ -14,7 +14,6 @@ Before:
   let g:ale_lsp_next_message_id = 1
   let g:ale_run_synchronously = 1
   let g:message_list = []
-  let g:Callback = ''
 
   function! LanguageCallback() abort
     return 'foobar'
@@ -34,9 +33,7 @@ Before:
   \ })
   let g:ale_linters = {'foobar': ['dummy_linter']}
 
-  function! ale#lsp_linter#StartLSP(buffer, linter, callback) abort
-    let g:Callback = a:callback
-
+  function! ale#lsp_linter#StartLSP(buffer, linter) abort
     let l:conn = ale#lsp#NewConnection({})
     let l:conn.id = 347
     let l:conn.open_documents = {a:buffer : -1}
@@ -59,7 +56,6 @@ After:
 
   unlet! b:ale_enabled
   unlet! b:ale_linters
-  unlet! g:Callback
   unlet! g:message_list
 
   delfunction LanguageCallback

test/lsp/test_lsp_command_formatting.vader

@@ -23,15 +23,14 @@ Execute(Command formatting should be applied correctly for LSP linters):
   \   'executable': has('win32') ? 'cmd': 'true',
   \   'command': '%e --foo',
   \ },
-  \ {->0}
   \)
 
   if has('win32')
     AssertEqual
-    \ ['cmd', 'cmd /s/c "cmd --foo"', '/foo/bar'],
-    \ g:args[:2]
+    \ ['cmd', 'cmd /s/c "cmd --foo"', {}],
+    \ g:args
   else
     AssertEqual
-    \ ['true', [&shell, '-c', '''true'' --foo'], '/foo/bar'],
-    \ g:args[:2]
+    \ ['true', [&shell, '-c', '''true'' --foo'], {}],
+    \ g:args
   endif

test/lsp/test_lsp_connections.vader

@@ -2,6 +2,10 @@ Before:
   let g:ale_lsp_next_message_id = 1
 
 After:
+  if exists('b:conn') && has_key(b:conn, 'id')
+    call ale#lsp#RemoveConnectionWithID(b:conn.id)
+  endif
+
   unlet! b:data
   unlet! b:conn
 
@@ -223,17 +227,20 @@ Execute(ale#lsp#ReadMessageData() should handle a message with part of a second
   \ )
 
 Execute(Projects with regular project roots should be registered correctly):
-  let b:conn = {'projects': {}}
-
-  call ale#lsp#RegisterProject(b:conn, '/foo/bar')
+  let b:conn = ale#lsp#NewConnection({})
+  call ale#lsp#RegisterProject(b:conn.id, '/foo/bar')
 
   AssertEqual
   \ {
-  \   'projects': {
-  \     '/foo/bar': {'initialized': 0, 'message_queue': [], 'init_request_id': 0},
+  \   '/foo/bar': {
+  \     'root': '/foo/bar',
+  \     'initialized': 0,
+  \     'message_queue': [],
+  \     'capabilities_queue': [],
+  \     'init_request_id': 0,
   \   },
   \ },
-  \ b:conn
+  \ b:conn.projects
 
 Execute(Projects with regular project roots should be fetched correctly):
   let b:conn = {
@@ -247,17 +254,20 @@ Execute(Projects with regular project roots should be fetched correctly):
   \ ale#lsp#GetProject(b:conn, '/foo/bar')
 
 Execute(Projects with empty project roots should be registered correctly):
-  let b:conn = {'projects': {}}
-
-  call ale#lsp#RegisterProject(b:conn, '')
+  let b:conn = ale#lsp#NewConnection({})
+  call ale#lsp#RegisterProject(b:conn.id, '')
 
   AssertEqual
   \ {
-  \   'projects': {
-  \     '<<EMPTY>>': {'initialized': 1, 'message_queue': [], 'init_request_id': 0},
+  \   '<<EMPTY>>': {
+  \     'root': '',
+  \     'initialized': 1,
+  \     'message_queue': [],
+  \     'capabilities_queue': [],
+  \     'init_request_id': 0,
   \   },
   \ },
-  \ b:conn
+  \ b:conn.projects
 
 Execute(Projects with empty project roots should be fetched correctly):
   let b:conn = {

test/lsp/test_other_initialize_message_handling.vader

@@ -3,6 +3,7 @@ Before:
   \ 'initialized': 0,
   \ 'init_request_id': 3,
   \ 'message_queue': [],
+  \ 'capabilities_queue': [],
   \}
 
   let b:conn = {
@@ -34,6 +35,7 @@ Execute(publishDiagnostics messages with files inside project directories should
   \   'initialized': 0,
   \   'init_request_id': 3,
   \   'message_queue': [],
+  \   'capabilities_queue': [],
   \ },
   \ b:project
 
@@ -47,6 +49,7 @@ Execute(publishDiagnostics messages with files inside project directories should
   \   'initialized': 1,
   \   'init_request_id': 3,
   \   'message_queue': [],
+  \   'capabilities_queue': [],
   \ },
   \ b:project
 
@@ -60,6 +63,7 @@ Execute(Messages with no method and capabilities should initialize projects):
   \   'initialized': 1,
   \   'init_request_id': 3,
   \   'message_queue': [],
+  \   'capabilities_queue': [],
   \ },
   \ b:project
 
@@ -120,6 +124,7 @@ Execute(Capabilities should bet set up correctly):
   \     '/foo/bar': {
   \       'initialized': 1,
   \       'message_queue': [],
+  \       'capabilities_queue': [],
   \       'init_request_id': 3,
   \     },
   \   },
@@ -170,6 +175,7 @@ Execute(Disabled capabilities should be recognised correctly):
   \     '/foo/bar': {
   \       'initialized': 1,
   \       'message_queue': [],
+  \       'capabilities_queue': [],
   \       'init_request_id': 3,
   \     },
   \   },