diff -r c39ddff53694 Lib/idlelib/IdleHistory.py
--- a/Lib/idlelib/IdleHistory.py	Mon Jul 01 00:42:52 2013 -0400
+++ b/Lib/idlelib/IdleHistory.py	Thu Jul 11 03:18:03 2013 +0530
@@ -86,3 +86,8 @@
             self.history.append(source)
         self.history_pointer = None
         self.history_prefix = None
+
+if __name__ == "__main__":
+    from test import support; support.use_resources = ['gui']
+    import unittest
+    unittest.main('idlelib.idle_test.test_idlehistory', verbosity=2, exit=False)
diff -r c39ddff53694 Lib/idlelib/idle_test/test_idlehistory.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/idlelib/idle_test/test_idlehistory.py	Thu Jul 11 03:18:03 2013 +0530
@@ -0,0 +1,52 @@
+import unittest
+import idlelib.IdleHistory as ihis
+from idlelib.idle_test.mock_tk import Text
+from idlelib.configHandler import idleConf
+
+
+class IdleHistoryTest(unittest.TestCase):
+
+    def setUp(self):
+        self.mytext = Text()  
+        self.mytext.insert('1.0', "  idlehistory test  ")  
+        self.myhistory = ihis.History(self.mytext)
+
+    def TearDown(self):
+        self.mytext = None
+        self.myhistory = None
+
+    def test_myhistory(self):
+        self.assertIs(self.myhistory.text, self.mytext)
+        self.assertEqual(self.myhistory.history,[])
+        self.assertIsNone(self.myhistory.history_prefix)
+        self.assertIsNone(self.myhistory.history_pointer)
+        self.assertEqual(self.myhistory.cyclic, idleConf.GetOption("main",
+                                           "History", "cyclic", 1, "bool"))
+        self.assertEqual(self.myhistory.output_sep,"\n")
+
+    def test_duplicates_history_store(self):
+        # source having length less than 3 (after stripped) should be avoided
+        source = self.mytext.get('1.0','1.4')
+        self.myhistory.history_store(source)
+        self.assertEqual(self.myhistory.history, [])
+
+    def test_history_store(self):
+        source = self.mytext.get('1.0','1.6')
+        self.myhistory.history_store(source)
+        self.assertEqual(self.myhistory.history, ['idle'])
+
+    def test_history_do_next(self):
+        """
+        source = self.mytext.get('1.0','1.6')
+        self.myhistory.history_store(source)
+        self.myhistory.history_do(0) 
+
+        gives following error on _decode
+        /cpython/Lib/idlelib/idle_test/mock_tk.py", line 102, in _decode
+        line, col = position.split('.')
+        ValueError: need more than 1 value to unpack
+        """
+        
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, exit=2)