Add jscs linter

ale_linters/javascript/jscs.vim

@@ -0,0 +1,47 @@
+if exists('g:loaded_ale_linters_javascript_jscs')
+    finish
+endif
+
+let g:loaded_ale_linters_javascript_jscs = 1
+
+function! ale_linters#javascript#jscs#Handle(buffer, lines)
+    " Matches patterns line the following:
+    "
+    " input:57:8: Unexpected token (57:8)
+    let pattern = '^.\+:\(\d\+\):\(\d\+\): \(.\+\)'
+    let output = []
+
+    for line in a:lines
+        let l:match = matchlist(line, pattern)
+
+        if len(l:match) == 0
+            continue
+        endif
+
+        let text = l:match[3]
+        let marker_parts = l:match[4]
+
+        if len(marker_parts) == 2
+            let text = text . ' (' . marker_parts[1] . ')'
+        endif
+
+        " vcol is Needed to indicate that the column is a character.
+        call add(output, {
+        \   'bufnr': a:buffer,
+        \   'lnum': l:match[1] + 0,
+        \   'vcol': 0,
+        \   'col': l:match[2] + 0,
+        \   'text': text,
+        \   'type': 'E',
+        \   'nr': -1,
+        \})
+    endfor
+
+    return output
+endfunction
+
+call ALEAddLinter('javascript', {
+\   'executable': 'jscs',
+\   'command': 'jscs -r unix -n -',
+\   'callback': 'ale_linters#javascript#jscs#Handle',
+\})