Add asyncomplete.vim Support (#2627)

autoload/ale/completion.vim

@@ -267,6 +267,14 @@ function! ale#completion#Show(result) abort
         \   {-> ale#util#FeedKeys("\<Plug>(ale_show_completion_menu)")}
         \)
     endif
+
+    if l:source is# 'ale-callback'
+        call b:CompleteCallback(b:ale_completion_result)
+    endif
+endfunction
+
+function! ale#completion#GetAllTriggers() abort
+    return deepcopy(s:trigger_character_map)
 endfunction
 
 function! s:CompletionStillValid(request_id) abort
@@ -280,6 +288,7 @@ function! s:CompletionStillValid(request_id) abort
     \   b:ale_completion_info.column == l:column
     \   || b:ale_completion_info.source is# 'deoplete'
     \   || b:ale_completion_info.source is# 'ale-omnifunc'
+    \   || b:ale_completion_info.source is# 'ale-callback'
     \)
 endfunction
 
@@ -560,12 +569,25 @@ endfunction
 
 " This function can be used to manually trigger autocomplete, even when
 " g:ale_completion_enabled is set to false
-function! ale#completion#GetCompletions(source) abort
+function! ale#completion#GetCompletions(...) abort
+    let l:source = get(a:000, 0, '')
+    let l:options = get(a:000, 1, {})
+
+    if len(a:000) > 2
+        throw 'Too many arguments!'
+    endif
+
+    let l:CompleteCallback = get(l:options, 'callback', v:null)
+
+    if l:CompleteCallback isnot v:null
+        let b:CompleteCallback = l:CompleteCallback
+    endif
+
     let [l:line, l:column] = getpos('.')[1:2]
 
     let l:prefix = ale#completion#GetPrefix(&filetype, l:line, l:column)
 
-    if a:source is# 'ale-automatic' && empty(l:prefix)
+    if l:source is# 'ale-automatic' && empty(l:prefix)
         return 0
     endif
 
@@ -578,7 +600,7 @@ function! ale#completion#GetCompletions(source) abort
     \   'prefix': l:prefix,
     \   'conn_id': 0,
     \   'request_id': 0,
-    \   'source': a:source,
+    \   'source': l:source,
     \}
     unlet! b:ale_completion_result
 

autoload/asyncomplete/sources/ale.vim

@@ -0,0 +1,26 @@
+function! asyncomplete#sources#ale#get_source_options(...) abort
+    let l:default = extend({
+    \     'name': 'ale',
+    \     'completor': function('asyncomplete#sources#ale#completor'),
+    \     'whitelist': ['*'],
+    \     'triggers': asyncomplete#sources#ale#get_triggers(),
+    \ }, a:0 >= 1 ? a:1 : {})
+
+    return extend(l:default, {'refresh_pattern': '\k\+$'})
+endfunction
+
+function! asyncomplete#sources#ale#get_triggers() abort
+    let l:triggers = ale#completion#GetAllTriggers()
+    let l:triggers['*'] = l:triggers['<default>']
+
+    return l:triggers
+endfunction
+
+function! asyncomplete#sources#ale#completor(options, context) abort
+    let l:keyword = matchstr(a:context.typed, '\w\+$')
+    let l:startcol = a:context.col - len(l:keyword)
+
+    call ale#completion#GetCompletions('ale-callback', { 'callback': {completions ->
+    \   asyncomplete#complete(a:options.name, a:context, l:startcol, completions)
+    \ }})
+endfunction

doc/ale.txt

@@ -341,6 +341,17 @@ completion source for Deoplete is named `'ale'`, and should enabled
 automatically if Deoplete is enabled and configured correctly. Deoplete
 integration should not be combined with ALE's own implementation.
 
+                                                 *ale-asyncomplete-integration*
+
+ALE additionally integrates with asyncomplete.vim for offering automatic
+completion data. ALE's asyncomplete source requires registration and should
+use the defaults provided by the|asyncomplete#sources#ale#get_source_options| function >
+
+  " Use ALE's function for asyncomplete defaults
+  au User asyncomplete_setup call asyncomplete#register_source(asyncomplete#sources#ale#get_source_options({
+      \ 'priority': 10, " Provide your own overrides here
+      \ }))
+>
 ALE also offers its own completion implementation, which does not require any
 other plugins. Suggestions will be made while you type after completion is
 enabled. ALE's own completion implementation can be enabled by setting

test/completion/test_completion_events.vader

@@ -62,6 +62,10 @@ After:
 
   delfunction CheckCompletionCalled
 
+  if exists('*CompleteCallback')
+    delfunction CompleteCallback
+  endif
+
   " Stop any timers we left behind.
   " This stops the tests from failing randomly.
   call ale#completion#StopTimer()
@@ -333,6 +337,30 @@ Execute(b:ale_completion_info should be set up correctly for other sources):
   \ b:ale_completion_info
   Assert !exists('b:ale_completion_result')
 
+Execute(b:ale_completion_info should be set up correctly when requesting completions via callback):
+  let b:ale_completion_result = []
+  call setpos('.', [bufnr(''), 3, 14, 0])
+
+  function! CompleteCallback() abort
+    echo 'Called'
+  endfunction
+
+
+  call ale#completion#GetCompletions('ale-callback', {'callback': funcref('CompleteCallback')})
+
+  AssertEqual
+  \ {
+  \   'request_id': 0,
+  \   'conn_id': 0,
+  \   'column': 14,
+  \   'line_length': 14,
+  \   'line': 3,
+  \   'prefix': 'ab',
+  \   'source': 'ale-callback',
+  \ },
+  \ b:ale_completion_info
+  Assert !exists('b:ale_completion_result')
+
 Execute(The correct keybinds should be configured):
   redir => g:output
     silent map <Plug>(ale_show_completion_menu)