Fix #555 - Handle csslint errors without groups

autoload/ale/handlers/css.vim

@@ -10,17 +10,20 @@ function! ale#handlers#css#HandleCSSLintFormat(buffer, lines) abort
     "
     " These errors can be very massive, so the type will be moved to the front
     " so you can actually read the error type.
-    let l:pattern = '^.*: line \(\d\+\), col \(\d\+\), \(Error\|Warning\) - \(.\+\) (\([^)]\+\))$'
+    let l:pattern = '\v^.*: line (\d+), col (\d+), (Error|Warning) - (.+)$'
     let l:output = []
 
     for l:match in ale#util#GetMatches(a:lines, l:pattern)
         let l:text = l:match[4]
         let l:type = l:match[3]
-        let l:errorGroup = l:match[5]
+
+        let l:group_match = matchlist(l:text, '\v^(.+) \((.+)\)$')
 
         " Put the error group at the front, so we can see what kind of error
         " it is on small echo lines.
-        let l:text = '(' . l:errorGroup . ') ' . l:text
+        if !empty(l:group_match)
+            let l:text = '(' . l:group_match[2] . ') ' . l:group_match[1]
+        endif
 
         call add(l:output, {
         \   'lnum': l:match[1] + 0,

test/handler/test_common_handlers.vader

@@ -11,12 +11,33 @@ Execute(HandleCSSLintFormat should handle CSS errors):
   \    'lnum': 2,
   \    'col': 5,
   \    'type': 'W',
-  \    'text': "(known-properties) Expected ... but found 'wat'.",
+  \    'text': '(known-properties) Expected ... but found ''wat''.',
   \   },
   \ ],
   \ ale#handlers#css#HandleCSSLintFormat(42, [
   \   'something.css: line 2, col 1, Error - Expected RBRACE at line 2, col 1. (errors)',
-  \   "something.css: line 2, col 5, Warning - Expected ... but found 'wat'. (known-properties)",
+  \   'something.css: line 2, col 5, Warning - Expected ... but found ''wat''. (known-properties)',
+  \ ])
+
+Execute(HandleCSSLintFormat should handle CSS errors without groups):
+  AssertEqual
+  \ [
+  \   {
+  \    'lnum': 7,
+  \    'col': 3,
+  \    'type': 'W',
+  \    'text': 'Unknown property ''fill''.',
+  \   },
+  \   {
+  \    'lnum': 8,
+  \    'col': 3,
+  \    'type': 'W',
+  \    'text': 'Unknown property ''fill-opacity''.',
+  \   },
+  \ ],
+  \ ale#handlers#css#HandleCSSLintFormat(42, [
+  \   'something.css: line 7, col 3, Warning - Unknown property ''fill''.',
+  \   'something.css: line 8, col 3, Warning - Unknown property ''fill-opacity''.',
   \ ])
 
 Execute (HandlePEP8Format should handle the correct lines of output):