Use different reporter to support older versions of jscs (#737)

* Use different reporter to support older versions of jscs

* Add test and make more consistent with other code

* Add documentation for jscs

* Add more test coverage

ale_linters/javascript/jscs.vim

@@ -1,9 +1,63 @@
 " Author: Chris Kyrouac - https://github.com/fijshion
 " Description: jscs for JavaScript files
 
+call ale#Set('javascript_jscs_executable', 'jscs')
+call ale#Set('javascript_jscs_use_global', 0)
+
+function! ale_linters#javascript#jscs#GetExecutable(buffer) abort
+    return ale#node#FindExecutable(a:buffer, 'javascript_jscs', [
+    \   'node_modules/.bin/jscs',
+    \])
+endfunction
+
+function! ale_linters#javascript#jscs#GetCommand(buffer) abort
+    " Search for a local JShint config locaation, and default to a global one.
+    let l:jscs_config = ale#path#ResolveLocalPath(
+    \   a:buffer,
+    \   '.jscsrc',
+    \   get(g:, 'ale_jscs_config_loc', '')
+    \)
+
+    let l:command = ale#Escape(ale_linters#javascript#jscs#GetExecutable(a:buffer))
+    let l:command .= ' --reporter inline --no-colors'
+
+    if !empty(l:jscs_config)
+        let l:command .= ' --config ' . ale#Escape(l:jscs_config)
+    endif
+
+    let l:command .= ' -'
+
+    return l:command
+endfunction
+
+function! ale_linters#javascript#jscs#Handle(buffer, lines) abort
+    " Matches patterns looking like the following
+    "
+    " foobar.js: line 2, col 1, Expected indentation of 1 characters
+    "
+    let l:pattern = '^.*:\s\+line \(\d\+\),\s\+col\s\+\(\d\+\),\s\+\(.*\)$'
+    let l:output = []
+    let l:m = ale#util#GetMatches(a:lines, [l:pattern])
+
+    for l:match in l:m
+        let l:text = l:match[3]
+
+        let l:obj = {
+        \   'lnum': l:match[1] + 0,
+        \   'col': l:match[2] + 0,
+        \   'text': l:match[3]
+        \}
+
+        call add(l:output, l:obj)
+    endfor
+
+    return l:output
+endfunction
+
 call ale#linter#Define('javascript', {
 \   'name': 'jscs',
-\   'executable': 'jscs',
-\   'command': 'jscs -r unix -n -',
-\   'callback': 'ale#handlers#unix#HandleAsError',
+\   'executable_callback': 'ale_linters#javascript#jscs#GetExecutable',
+\   'command_callback': 'ale_linters#javascript#jscs#GetCommand',
+\   'callback': 'ale_linters#javascript#jscs#Handle',
 \})
+