query: sort_on must handle null value

src/queries/query.js

@@ -47,7 +47,7 @@
       value = [value];
     }
     for (i = 0; i < value.length; i += 1) {
-      if (typeof value[i] === 'object') {
+      if ((value[i] !== null) && (typeof value[i] === 'object')) {
         new_value[i] = value[i].content;
       } else {
         new_value[i] = value[i];

test/queries/tests.js

@@ -710,4 +710,28 @@
       }).always(start);
   });
 
+  test('sort_on options do not raise in case of null value', function () {
+    var doc_list = [
+      {'a': null},
+      {'c': 3},
+      {'b': 2}
+    ];
+
+    stop();
+    expect(1);
+    jIO.QueryFactory.create("").exec(
+      doc_list,
+      {
+        sort_on: [['a', 'ascending']],
+      }
+    )
+      .then(function (list) {
+        deepEqual(list, [
+          {'c': 3},
+          {'b': 2},
+          {'a': null}
+        ], 'Sorting didn\'t raise');
+      }).always(start);
+  });
+
 }(jIO, jiodate));