Add few more tests.

Author: serhiy-storchaka

Lib/test/test_userdict.py

@@ -168,14 +168,21 @@ def test_init(self):
     def test_data(self):
         u = UserDict()
         self.assertEqual(u.data, {})
+        self.assertIs(type(u.data), dict)
         d = {'a': 1, 'b': 2}
         u = UserDict(d)
         self.assertEqual(u.data, d)
         self.assertIsNot(u.data, d)
+        self.assertIs(type(u.data), dict)
+        u = UserDict(u)
+        self.assertEqual(u.data, d)
+        self.assertIs(type(u.data), dict)
         u = UserDict([('a', 1), ('b', 2)])
         self.assertEqual(u.data, d)
+        self.assertIs(type(u.data), dict)
         u = UserDict(a=1, b=2)
         self.assertEqual(u.data, d)
+        self.assertIs(type(u.data), dict)
 
     def test_update(self):
         for kw in 'self', 'dict', 'other', 'iterable':

Lib/test/test_userlist.py

@@ -19,12 +19,18 @@ class UserListTest(list_tests.CommonTest):
     def test_data(self):
         u = UserList()
         self.assertEqual(u.data, [])
+        self.assertIs(type(u.data), list)
         a = [1, 2]
         u = UserList(a)
         self.assertEqual(u.data, a)
         self.assertIsNot(u.data, a)
+        self.assertIs(type(u.data), list)
+        u = UserList(u)
+        self.assertEqual(u.data, a)
+        self.assertIs(type(u.data), list)
         u = UserList("spam")
         self.assertEqual(u.data, list("spam"))
+        self.assertIs(type(u.data), list)
 
     def test_getslice(self):
         super().test_getslice()

Lib/test/test_userstring.py

@@ -49,6 +49,17 @@ def checkcall(self, object, methodname, *args):
         # we don't fix the arguments, because UserString can't cope with it
         getattr(object, methodname)(*args)
 
+    def test_data(self):
+        u = UserString("spam")
+        self.assertEqual(u.data, "spam")
+        self.assertIs(type(u.data), str)
+        u = UserString(u)
+        self.assertEqual(u.data, "spam")
+        self.assertIs(type(u.data), str)
+        u = UserString(42)
+        self.assertEqual(u.data, "42")
+        self.assertIs(type(u.data), str)
+
     def test_mixed_add(self):
         u = UserString("spam") + "eggs"
         self.assertEqual(u, "spameggs")