diff --git a/test/utlity_test.dart b/test/utlity_test.dart
index 9d12f88..07ca10e 100644
--- a/test/utlity_test.dart
+++ b/test/utlity_test.dart
@@ -1,3 +1,5 @@
+import 'dart:math';
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:fitlien_common/utility.dart';
 
@@ -86,4 +88,28 @@ void main() {
     expect(deltas[1].wordDeltas[1].old!.text, "ef");
     expect(deltas[1].wordDeltas[1].modified, null);
   });
+
+  test('Comparison test 6', () {
+    var text1 = "ab bc cd ef";
+    var text2 = "ab bd cd ef";
+    var deltas = Utility.compare(text1, text2);
+    expect(deltas.length, 1);
+    expect(deltas[0].wordDeltas.length, 1);
+    expect(deltas[0].wordDeltas[0].old!.text, "bc");
+    expect(deltas[0].wordDeltas[0].modified!.text, "bd");
+  });
+
+  test('Comparison test 7', () {
+    var text1 = "abc def ghi";
+    var text2 = "zbc dkf gha";
+    var deltas = Utility.compare(text1, text2);
+    expect(deltas.length, 1);
+    expect(deltas[0].wordDeltas.length, 3);
+    expect(deltas[0].wordDeltas[0].old!.text, "abc");
+    expect(deltas[0].wordDeltas[0].modified!.text, "zbc");
+    expect(deltas[0].wordDeltas[1].old!.text, "def");
+    expect(deltas[0].wordDeltas[1].modified!.text, "dkf");
+    expect(deltas[0].wordDeltas[2].old!.text, "ghi");
+    expect(deltas[0].wordDeltas[2].modified!.text, "gha");
+  });
 }