validation for find and findOne methods

test/unit/Container-test.js

@@ -1089,6 +1089,47 @@ suite('Container', function() {
         layer.draw();
     });
 
+
+
+    test('warn on invalid selector', function() {
+        var stage = addStage();
+        var layer = new Konva.Layer({
+            name: 'layerName',
+            id: 'layerId'
+        });
+        var group = new Konva.Group({
+            name: 'groupName',
+            id: 'groupId'
+        });
+        var rect = new Konva.Rect({
+            x: 200,
+            y: 20,
+            width: 100,
+            height: 50,
+            fill: 'red',
+            stroke: 'black',
+            strokeWidth: 4,
+            name: 'rectName',
+            id: 'rectId'
+        });
+
+        stage.add(layer);
+        layer.add(group);
+        group.add(rect);
+        layer.draw();
+
+        var counter = 0;
+        var oldWarn = Konva.Util.warn;
+        Konva.Util.warn = function() {
+            counter += 1;
+        };
+
+        // forgot dot
+        group.find('rectName');
+        assert.equal(counter > 0, true);
+        Konva.Util.warn = oldWarn;
+    });
+
     // ======================================================
     test('add layer then shape', function() {
         var stage = addStage();