add class docstring test

Author: xuantengh

Lib/test/test_code.py

@@ -178,6 +178,19 @@
 nlocals: 3
 flags: 3
 consts: ("'hello'", "'world'")
+
+>>> class class_with_docstring:
+...     '''This is a docstring for class'''
+...     pass
+
+>>> print(class_with_docstring.__doc__)
+This is a docstring for class
+
+>>> class class_without_docstring:
+...     pass
+
+>>> print(class_without_docstring.__doc__)
+None
 """
 
 import copy

Lib/test/test_compile.py

@@ -344,6 +344,7 @@ def test_lambda_doc(self):
     def test_lambda_consts(self):
         l = lambda: "this is the only const"
         self.assertEqual(len(l.__code__.co_consts), 1)
+        self.assertEqual(l.__code__.co_consts[0], "this is the only const")
 
     def test_encoding(self):
         code = b'# -*- coding: badencoding -*-\npass\n'