From b4513fc4b0381bdff00c52e294e6da6c7f27aa19 Mon Sep 17 00:00:00 2001
From: Nick Gavalas <njg@fb.com>
Date: Mon, 10 Sep 2018 18:55:49 -0400
Subject: [PATCH] fix non-. prefix triggers overfiltering results

---
 autoload/ale/completion.vim                   |  8 +++---
 .../test_completion_filtering.vader           | 26 ++++++++++++++-----
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/autoload/ale/completion.vim b/autoload/ale/completion.vim
index e96774c3..2556d50c 100644
--- a/autoload/ale/completion.vim
+++ b/autoload/ale/completion.vim
@@ -98,14 +98,15 @@ function! ale#completion#GetTriggerCharacter(filetype, prefix) abort
     return ''
 endfunction
 
-function! ale#completion#Filter(buffer, suggestions, prefix) abort
+function! ale#completion#Filter(buffer, filetype, suggestions, prefix) abort
     let l:excluded_words = ale#Var(a:buffer, 'completion_excluded_words')
+    let l:triggers = s:GetFiletypeValue(s:trigger_character_map, a:filetype)
 
     " For completing...
     "   foo.
     "       ^
     " We need to include all of the given suggestions.
-    if a:prefix is# '.'
+    if index(l:triggers, a:prefix) >= 0
         let l:filtered_suggestions = a:suggestions
     else
         let l:filtered_suggestions = []
@@ -369,7 +370,7 @@ function! ale#completion#ParseLSPCompletions(response) abort
     endfor
 
     if has_key(l:info, 'prefix')
-        return ale#completion#Filter(l:buffer, l:results, l:info.prefix)
+        return ale#completion#Filter(l:buffer, &filetype, l:results, l:info.prefix)
     endif
 
     return l:results
@@ -390,6 +391,7 @@ function! ale#completion#HandleTSServerResponse(conn_id, response) abort
     if l:command is# 'completions'
         let l:names = ale#completion#Filter(
         \   l:buffer,
+        \   &filetype,
         \   ale#completion#ParseTSServerCompletions(a:response),
         \   b:ale_completion_info.prefix,
         \)[: g:ale_completion_max_suggestions - 1]
diff --git a/test/completion/test_completion_filtering.vader b/test/completion/test_completion_filtering.vader
index ae91a952..ffb313ef 100644
--- a/test/completion/test_completion_filtering.vader
+++ b/test/completion/test_completion_filtering.vader
@@ -12,16 +12,17 @@ After:
 Execute(Prefix filtering should work for Lists of strings):
   AssertEqual
   \ ['FooBar', 'foo'],
-  \ ale#completion#Filter(bufnr(''), ['FooBar', 'FongBar', 'baz', 'foo'], 'foo')
+  \ ale#completion#Filter(bufnr(''), '', ['FooBar', 'FongBar', 'baz', 'foo'], 'foo')
   AssertEqual
   \ ['FooBar', 'FongBar', 'baz', 'foo'],
-  \ ale#completion#Filter(bufnr(''), ['FooBar', 'FongBar', 'baz', 'foo'], '.')
+  \ ale#completion#Filter(bufnr(''), '', ['FooBar', 'FongBar', 'baz', 'foo'], '.')
 
 Execute(Prefix filtering should work for completion items):
   AssertEqual
   \ [{'word': 'FooBar'}, {'word': 'foo'}],
   \ ale#completion#Filter(
   \   bufnr(''),
+  \   '',
   \   [
   \     {'word': 'FooBar'},
   \     {'word': 'FongBar'},
@@ -40,6 +41,7 @@ Execute(Prefix filtering should work for completion items):
   \ ],
   \ ale#completion#Filter(
   \   bufnr(''),
+  \   '',
   \   [
   \     {'word': 'FooBar'},
   \     {'word': 'FongBar'},
@@ -56,6 +58,7 @@ Execute(Excluding words from completion results should work):
   \ [{'word': 'Italian'}],
   \ ale#completion#Filter(
   \   bufnr(''),
+  \   '',
   \   [
   \     {'word': 'Italian'},
   \     {'word': 'it'},
@@ -67,6 +70,7 @@ Execute(Excluding words from completion results should work):
   \ [{'word': 'Deutsch'}],
   \ ale#completion#Filter(
   \   bufnr(''),
+  \   '',
   \   [
   \     {'word': 'describe'},
   \     {'word': 'Deutsch'},
@@ -78,6 +82,7 @@ Execute(Excluding words from completion results should work):
   \ [{'word': 'Deutsch'}],
   \ ale#completion#Filter(
   \   bufnr(''),
+  \   '',
   \   [
   \     {'word': 'describe'},
   \     {'word': 'Deutsch'},
@@ -90,19 +95,26 @@ Execute(Excluding words from completion results should work with lists of String
 
   AssertEqual
   \ ['Italian'],
-  \ ale#completion#Filter(bufnr(''), ['Italian', 'it'], 'it')
+  \ ale#completion#Filter(bufnr(''), '', ['Italian', 'it'], 'it')
   AssertEqual
   \ ['Deutsch'],
-  \ ale#completion#Filter(bufnr(''), ['describe', 'Deutsch'], 'de')
+  \ ale#completion#Filter(bufnr(''), '', ['describe', 'Deutsch'], 'de')
   AssertEqual
   \ ['Deutsch'],
-  \ ale#completion#Filter(bufnr(''), ['describe', 'Deutsch'], '.')
+  \ ale#completion#Filter(bufnr(''), '', ['describe', 'Deutsch'], '.')
 
 Execute(Filtering shouldn't modify the original list):
   let b:ale_completion_excluded_words = ['it', 'describe']
   let b:suggestions = [{'word': 'describe'}]
 
-  AssertEqual [], ale#completion#Filter(bufnr(''), b:suggestions, '.')
+  AssertEqual [], ale#completion#Filter(bufnr(''), '', b:suggestions, '.')
   AssertEqual b:suggestions, [{'word': 'describe'}]
-  AssertEqual [], ale#completion#Filter(bufnr(''), b:suggestions, 'de')
+  AssertEqual [], ale#completion#Filter(bufnr(''), '', b:suggestions, 'de')
   AssertEqual b:suggestions, [{'word': 'describe'}]
+
+Execute(Filtering should respect filetype triggers):
+  let b:suggestions = [{'word': 'describe'}]
+
+  AssertEqual b:suggestions, ale#completion#Filter(bufnr(''), '', b:suggestions, '.')
+  AssertEqual b:suggestions, ale#completion#Filter(bufnr(''), 'rust', b:suggestions, '.')
+  AssertEqual b:suggestions, ale#completion#Filter(bufnr(''), 'rust', b:suggestions, '::')