Add TypeScript autoimport support for deoplete (#2779)

* Add autoimport support for deoplete

* Fix test_deoplete_source.py

* Use callback instead of is_async for deoplete

Shuogo, the author of Deoplete, does not recommend using the `is_async`
option:

> I think is_async is not recommended. It is not so useful and broken.
> You should use callback system instead.

Link: https://github.com/Shougo/deoplete.nvim/issues/1006#issuecomment-526797857

Incidentally, the same thread mentiones an issue started by w0rp:
https://github.com/Shougo/deoplete.nvim/issues/976

The deoplete docs also say is_async is deprecated:

> is_async        (Bool)
>     If the gather is asynchronous, the source must set
>     it to "True". A typical strategy for an asynchronous
>     gather_candidates method to use this flag is to
>     set is_async flag to True while results are being
>     produced in the background (optionally, returning them
>     as they become ready). Once background processing
>     has completed, is_async flag should be set to False
>     indicating that this is the last portion of the
>     candidates.
>
>     Note: The feature is deprecated and not recommended.
>     You should use callback system by
>     |deoplete#auto_complete()| instead.

Link: https://github.com/Shougo/deoplete.nvim/blob/master/doc/deoplete.txt

Co-authored-by: w0rp <w0rp@users.noreply.github.com>

4 files changed, 34 insertions, 71 deletions

diff --git a/autoload/ale/completion.vim b/autoload/ale/completion.vim
index d18de59d..80684a30 100644
--- a/autoload/ale/completion.vim
+++ b/autoload/ale/completion.vim
@@ -388,7 +388,6 @@ function! s:CompletionStillValid(request_id) abort
     \&& b:ale_completion_info.line == l:line
     \&& (
     \   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'
     \)
@@ -805,7 +804,9 @@ endfunction
 function! ale#completion#HandleUserData(completed_item) abort
     let l:source = get(get(b:, 'ale_completion_info', {}), 'source', '')
 
-    if l:source isnot# 'ale-automatic' && l:source isnot# 'ale-manual' && l:source isnot# 'ale-callback'
+    if l:source isnot# 'ale-automatic'
+    \&& l:source isnot# 'ale-manual'
+    \&& l:source isnot# 'ale-callback'
         return
     endif
 
diff --git a/rplugin/python3/deoplete/sources/ale.py b/rplugin/python3/deoplete/sources/ale.py
index 3955ed2d..ae1f4039 100644
--- a/rplugin/python3/deoplete/sources/ale.py
+++ b/rplugin/python3/deoplete/sources/ale.py
@@ -24,6 +24,7 @@ class Source(Base):
         self.rank = 1000
         self.is_bytepos = True
         self.min_pattern_length = 1
+        self.is_volatile = True
         # Do not forget to update s:trigger_character_map in completion.vim in
         # updating entries in this map.
         self.input_patterns = {
@@ -44,21 +45,16 @@ class Source(Base):
         if not self.vim.call('ale#completion#CanProvideCompletions'):
             return None
 
-        if context.get('is_refresh'):
-            context['is_async'] = False
+        event = context.get('event')
 
-        if context['is_async']:
-            # Result is the same as for omnifunc, or None.
+        if event == 'Async':
             result = self.vim.call('ale#completion#GetCompletionResult')
+            return result or []
 
-            if result is not None:
-                context['is_async'] = False
-
-                return result
-        else:
-            context['is_async'] = True
-
-            # Request some completion results.
-            self.vim.call('ale#completion#GetCompletions', 'deoplete')
+        if context.get('is_refresh'):
+            self.vim.command(
+                "call ale#completion#GetCompletions('ale-callback', " + \
+                "{'callback': {completions -> deoplete#auto_complete() }})"
+            )
 
         return []
diff --git a/test/completion/test_completion_events.vader b/test/completion/test_completion_events.vader
index d70fefeb..2ac2b15c 100644
--- a/test/completion/test_completion_events.vader
+++ b/test/completion/test_completion_events.vader
@@ -233,7 +233,7 @@ Execute(ale#completion#Show() should make the correct feedkeys() call for manual
   AssertEqual [["\<Plug>(ale_show_completion_menu)"]], g:feedkeys_calls
 
 Execute(ale#completion#Show() should not call feedkeys() for other sources):
-  let b:ale_completion_info = {'source': 'deoplete'}
+  let b:ale_completion_info = {'source': 'other-source'}
   call ale#completion#Show([{'word': 'x', 'kind': 'v', 'icase': 1}])
 
   sleep 1ms
@@ -334,7 +334,7 @@ Execute(b:ale_completion_info should be set up correctly when requesting complet
 Execute(b:ale_completion_info should be set up correctly for other sources):
   let b:ale_completion_result = []
   call setpos('.', [bufnr(''), 3, 14, 0])
-  call ale#completion#GetCompletions('deoplete')
+  call ale#completion#GetCompletions('ale-callback')
 
   AssertEqual
   \ {
@@ -344,7 +344,7 @@ Execute(b:ale_completion_info should be set up correctly for other sources):
   \   'line_length': 14,
   \   'line': 3,
   \   'prefix': 'ab',
-  \   'source': 'deoplete',
+  \   'source': 'ale-callback',
   \ },
   \ b:ale_completion_info
   Assert !exists('b:ale_completion_result')
diff --git a/test/python/test_deoplete_source.py b/test/python/test_deoplete_source.py
index 9e56a10d..8304fa25 100644
--- a/test/python/test_deoplete_source.py
+++ b/test/python/test_deoplete_source.py
@@ -8,15 +8,20 @@ ale_module = imp.load_source(
 
 
 class VimMock(object):
-    def __init__(self, call_list, call_results):
+    def __init__(self, call_list, call_results, commands):
         self.__call_list = call_list
         self.__call_results = call_results
 
+        self.__commands = commands
+
     def call(self, function, *args):
         self.__call_list.append((function, args))
 
         return self.__call_results.get(function, 0)
 
+    def command(self, command):
+        self.__commands.append(command)
+
 
 class DeopleteSourceTest(unittest.TestCase):
     def setUp(self):
@@ -24,8 +29,10 @@ class DeopleteSourceTest(unittest.TestCase):
 
         self.call_list = []
         self.call_results = {'ale#completion#CanProvideCompletions': 1}
+        self.commands = []
         self.source = ale_module.Source('vim')
-        self.source.vim = VimMock(self.call_list, self.call_results)
+        self.source.vim = VimMock(
+            self.call_list, self.call_results, self.commands)
 
     def test_attributes(self):
         """
@@ -48,6 +55,7 @@ class DeopleteSourceTest(unittest.TestCase):
                 'cpp': r'(\.|::|->)\w*$',
             },
             'is_bytepos': True,
+            'is_volatile': True,
             'mark': '[L]',
             'min_pattern_length': 1,
             'name': 'ale',
@@ -64,70 +72,28 @@ class DeopleteSourceTest(unittest.TestCase):
         ])
 
     def test_request_completion_results(self):
-        context = {'is_async': False}
+        context = {'event': 'TextChangedI', 'is_refresh': True}
 
         self.assertEqual(self.source.gather_candidates(context), [])
-        self.assertEqual(context, {'is_async': True})
         self.assertEqual(self.call_list, [
             ('ale#completion#CanProvideCompletions', ()),
-            ('ale#completion#GetCompletions', ('deoplete',)),
+        ])
+        self.assertEqual(self.commands, [
+            "call ale#completion#GetCompletions('ale-callback', " + \
+            "{'callback': {completions -> deoplete#auto_complete() }})"
         ])
 
     def test_request_completion_results_from_buffer_without_providers(self):
         self.call_results['ale#completion#CanProvideCompletions'] = 0
-        context = {'is_async': False}
+        context = {'event': 'TextChangedI', 'is_refresh': True}
 
         self.assertIsNone(self.source.gather_candidates(context), [])
-        self.assertEqual(context, {'is_async': False})
-        self.assertEqual(self.call_list, [
-            ('ale#completion#CanProvideCompletions', ()),
-        ])
-
-    def test_refresh_completion_results(self):
-        context = {'is_async': False}
-
-        self.assertEqual(self.source.gather_candidates(context), [])
-        self.assertEqual(context, {'is_async': True})
-        self.assertEqual(self.call_list, [
-            ('ale#completion#CanProvideCompletions', ()),
-            ('ale#completion#GetCompletions', ('deoplete',)),
-        ])
-
-        context = {'is_async': True, 'is_refresh': True}
-
-        self.assertEqual(self.source.gather_candidates(context), [])
-        self.assertEqual(context, {'is_async': True, 'is_refresh': True})
         self.assertEqual(self.call_list, [
             ('ale#completion#CanProvideCompletions', ()),
-            ('ale#completion#GetCompletions', ('deoplete',)),
-            ('ale#completion#CanProvideCompletions', ()),
-            ('ale#completion#GetCompletions', ('deoplete',)),
         ])
 
-    def test_poll_no_result(self):
-        context = {'is_async': True}
-        self.call_results['ale#completion#GetCompletionResult'] = None
-
-        self.assertEqual(self.source.gather_candidates(context), [])
-        self.assertEqual(context, {'is_async': True})
-        self.assertEqual(self.call_list, [
-            ('ale#completion#CanProvideCompletions', ()),
-            ('ale#completion#GetCompletionResult', ()),
-        ])
-
-    def test_poll_empty_result_ready(self):
-        context = {'is_async': True}
-        self.call_results['ale#completion#GetCompletionResult'] = []
-
-        self.assertEqual(self.source.gather_candidates(context), [])
-        self.assertEqual(context, {'is_async': False})
-        self.assertEqual(self.call_list, [
-            ('ale#completion#CanProvideCompletions', ()),
-            ('ale#completion#GetCompletionResult', ()),
-        ])
-
-    def test_poll_non_empty_result_ready(self):
-        context = {'is_async': True}
+    def test_async_event(self):
+        context = {'event': 'Async', 'is_refresh': True}
         self.call_results['ale#completion#GetCompletionResult'] = [
             {
                 'word': 'foobar',
@@ -147,7 +113,7 @@ class DeopleteSourceTest(unittest.TestCase):
                 'info': '',
             },
         ])
-        self.assertEqual(context, {'is_async': False})
+
         self.assertEqual(self.call_list, [
             ('ale#completion#CanProvideCompletions', ()),
             ('ale#completion#GetCompletionResult', ()),