Fixes #2982 - Implement g:ale_exclude_highlights

Particular highlights can now be excluded by providing Lists of regular
expressions.

autoload/ale/highlight.vim

@@ -210,6 +210,12 @@ function! ale#highlight#SetHighlights(buffer, loclist) abort
     " Set the list in the buffer variable.
     call setbufvar(str2nr(a:buffer), 'ale_highlight_items', l:new_list)
 
+    let l:exclude_list = ale#Var(a:buffer, 'exclude_highlights')
+
+    if !empty(l:exclude_list)
+        call filter(l:new_list, 'empty(ale#util#GetMatches(v:val.text, l:exclude_list))')
+    endif
+
     " Update highlights for the current buffer, which may or may not
     " be the buffer we just set highlights for.
     call ale#highlight#UpdateHighlights()

doc/ale.txt

@@ -923,6 +923,21 @@ g:ale_enabled                                                   *g:ale_enabled*
   See |g:ale_pattern_options| for more information on that option.
 
 
+g:ale_exclude_highlights                             *g:ale_exclude_highlights*
+b:ale_exclude_highlights                             *b:ale_exclude_highlights*
+
+  Type: |List|
+  Default: `[]`
+
+  A list of regular expressions for matching against highlight messages to
+  remove. For example: >
+
+  " Do not highlight messages matching strings like these.
+  let b:ale_exclude_highlights = ['line too long', 'foo.*bar']
+<
+  See also: |g:ale_set_highlights|
+
+
 g:ale_fixers                                                     *g:ale_fixers*
                                                                  *b:ale_fixers*
 
@@ -1609,6 +1624,8 @@ g:ale_set_highlights                                     *g:ale_set_highlights*
   match highlights, whereas the line highlights when signs are enabled will
   run to the edge of the screen.
 
+  Highlights can be excluded with the |g:ale_exclude_highlights| option.
+
 
 g:ale_set_loclist                                           *g:ale_set_loclist*
 

plugin/ale.vim

@@ -109,6 +109,9 @@ let g:ale_set_signs = get(g:, 'ale_set_signs', has('signs'))
 " This flag can be set to 0 to disable setting error highlights.
 let g:ale_set_highlights = get(g:, 'ale_set_highlights', has('syntax'))
 
+" This List can be configured to exclude particular highlights.
+let g:ale_exclude_highlights = get(g:, 'ale_exclude_highlights', [])
+
 " This flag can be set to 0 to disable echoing when the cursor moves.
 let g:ale_echo_cursor = get(g:, 'ale_echo_cursor', 1)
 

test/test_highlight_placement.vader

@@ -7,6 +7,8 @@ Before:
   Save g:ale_set_loclist
   Save g:ale_set_quickfix
   Save g:ale_set_signs
+  Save g:ale_exclude_highlights
+  Save b:ale_exclude_highlights
 
   runtime autoload/ale/highlight.vim
 
@@ -20,6 +22,8 @@ Before:
   let g:ale_set_quickfix = 0
   let g:ale_set_loclist = 0
   let g:ale_echo_cursor = 0
+  let g:ale_exclude_highlights = []
+  let b:ale_exclude_highlights = []
 
   function! GenerateResults(buffer, output)
     return [
@@ -363,6 +367,23 @@ Execute(Highlights should always be cleared when the buffer highlight list is em
     \ GetMatchesWithoutIDs()
   endif
 
+Execute(Highlights should be hidden when excluded):
+  let b:ale_exclude_highlights = ['ig.*ore', 'nope']
+
+  call ale#highlight#SetHighlights(bufnr('%'), [
+  \ {'bufnr': bufnr('%'), 'type': 'E', 'lnum': 1, 'col': 1, 'text': 'hello'},
+  \ {'bufnr': bufnr('%'), 'type': 'E', 'lnum': 2, 'col': 1, 'text': 'ignore'},
+  \ {'bufnr': bufnr('%'), 'type': 'E', 'lnum': 3, 'col': 1, 'text': 'nope'},
+  \ {'bufnr': bufnr('%'), 'type': 'E', 'lnum': 4, 'col': 1, 'text': 'world'},
+  \])
+
+  AssertEqual
+  \ [
+  \   {'group': 'ALEError', 'priority': 10, 'pos1': [1, 1, 1]},
+  \   {'group': 'ALEError', 'priority': 10, 'pos1': [4, 1, 1]},
+  \ ],
+  \ GetMatchesWithoutIDs()
+
 Execute(Highlights should be cleared when ALE is disabled):
   let g:ale_enabled = 1
   call ale#highlight#SetHighlights(bufnr(''), [