Output errors even with --quiet

Output results even if options.quiet is true. Adds a test to verify that
this is working properly.

Author: Arcanemagus

src/formatters/json.js

@@ -1,3 +1,5 @@
+/* globals JSON: true */
+
 CSSLint.addFormatter({
     //format information
     id: "json",
@@ -24,10 +26,11 @@ CSSLint.addFormatter({
     /**
      * Given CSS Lint results for a file, return output for this format.
      * @param results {Object} with error and warning messages
+     * @param filename {String} relative file path (Unused)
      * @return {String} output for results
      */
     formatResults: function(results, filename, options) {
         "use strict";
-        return options.quiet ? "" : JSON.stringify(results);
+        return options.quiet && results.messages.length < 1 ? "" : JSON.stringify(results);
     }
-});
+});

tests/formatters/json.js

@@ -18,6 +18,16 @@
             Assert.areEqual("", actual);
         },
 
+        "Should have output when quiet option is specified and there are errors": function() {
+            var result = { messages: [
+                { type: "warning", line: 1, col: 1, message: "BOGUS", evidence: "ALSO BOGUS", rule: [] },
+                { type: "error", line: 2, col: 1, message: "BOGUS", evidence: "ALSO BOGUS", rule: [] }
+            ], stats: [] },
+                expected = "{\"messages\":[{\"type\":\"warning\",\"line\":1,\"col\":1,\"message\":\"BOGUS\",\"evidence\":\"ALSO BOGUS\",\"rule\":[]},{\"type\":\"error\",\"line\":2,\"col\":1,\"message\":\"BOGUS\",\"evidence\":\"ALSO BOGUS\",\"rule\":[]}],\"stats\":[]}",
+                actual = CSSLint.getFormatter("json").formatResults(result, "path/to/FILE", {fullPath: "/absolute/path/to/FILE", quiet: "true"});
+            Assert.areEqual(expected, actual);
+        },
+
         "File with problems should list them": function() {
             var result = { messages: [
                 { type: "warning", line: 1, col: 1, message: "BOGUS", evidence: "ALSO BOGUS", rule: [] },