added case of empty object and empty array

example.json

@@ -8,5 +8,7 @@
   "grault": 1,
   "garply": true,
   "waldo": "false",
-  "fred": "undefined"
+  "fred": "undefined",
+  "emptyarr": [],
+  "emptyobj": {}
 }

index.js

@@ -34,6 +34,11 @@
           var output = ''
             ;
 
+          if (0 === x.length) {
+            output += '[]';
+            return output;
+          }
+
           indentLevel = indentLevel.replace(/$/, '  ');
           x.forEach(function (y) {
             // TODO how should `undefined` be handled?
@@ -55,6 +60,11 @@
           var output = ''
             ;
 
+          if (0 === Object.keys(x).length) {
+            output += '{}';
+            return output;
+          }
+
           indentLevel = indentLevel.replace(/$/, '  ');
           Object.keys(x).forEach(function (k) {
             var val = x[k]