Add functools.update_wrapper() and functools.wraps() as described in PEP 356

Lib/test/test_functools.py

@@ -152,6 +152,113 @@ class TestPythonPartial(TestPartial):
 
     thetype = PythonPartial
 
+class TestUpdateWrapper(unittest.TestCase):
+
+    def check_wrapper(self, wrapper, wrapped,
+                      assigned=functools.WRAPPER_ASSIGNMENTS,
+                      updated=functools.WRAPPER_UPDATES):
+        # Check attributes were assigned
+        for name in assigned:
+            self.failUnless(getattr(wrapper, name) is getattr(wrapped, name))
+        # Check attributes were updated
+        for name in updated:
+            wrapper_attr = getattr(wrapper, name)
+            wrapped_attr = getattr(wrapped, name)
+            for key in wrapped_attr:
+                self.failUnless(wrapped_attr[key] is wrapper_attr[key])
+
+    def test_default_update(self):
+        def f():
+            """This is a test"""
+            pass
+        f.attr = 'This is also a test'
+        def wrapper():
+            pass
+        functools.update_wrapper(wrapper, f)
+        self.check_wrapper(wrapper, f)
+        self.assertEqual(wrapper.__name__, 'f')
+        self.assertEqual(wrapper.__doc__, 'This is a test')
+        self.assertEqual(wrapper.attr, 'This is also a test')
+
+    def test_no_update(self):
+        def f():
+            """This is a test"""
+            pass
+        f.attr = 'This is also a test'
+        def wrapper():
+            pass
+        functools.update_wrapper(wrapper, f, (), ())
+        self.check_wrapper(wrapper, f, (), ())
+        self.assertEqual(wrapper.__name__, 'wrapper')
+        self.assertEqual(wrapper.__doc__, None)
+        self.failIf(hasattr(wrapper, 'attr'))
+
+    def test_selective_update(self):
+        def f():
+            pass
+        f.attr = 'This is a different test'
+        f.dict_attr = dict(a=1, b=2, c=3)
+        def wrapper():
+            pass
+        wrapper.dict_attr = {}
+        assign = ('attr',)
+        update = ('dict_attr',)
+        functools.update_wrapper(wrapper, f, assign, update)
+        self.check_wrapper(wrapper, f, assign, update)
+        self.assertEqual(wrapper.__name__, 'wrapper')
+        self.assertEqual(wrapper.__doc__, None)
+        self.assertEqual(wrapper.attr, 'This is a different test')
+        self.assertEqual(wrapper.dict_attr, f.dict_attr)
+
+
+class TestWraps(TestUpdateWrapper):
+
+    def test_default_update(self):
+        def f():
+            """This is a test"""
+            pass
+        f.attr = 'This is also a test'
+        @functools.wraps(f)
+        def wrapper():
+            pass
+        self.check_wrapper(wrapper, f)
+        self.assertEqual(wrapper.__name__, 'f')
+        self.assertEqual(wrapper.__doc__, 'This is a test')
+        self.assertEqual(wrapper.attr, 'This is also a test')
+
+    def test_no_update(self):
+        def f():
+            """This is a test"""
+            pass
+        f.attr = 'This is also a test'
+        @functools.wraps(f, (), ())
+        def wrapper():
+            pass
+        self.check_wrapper(wrapper, f, (), ())
+        self.assertEqual(wrapper.__name__, 'wrapper')
+        self.assertEqual(wrapper.__doc__, None)
+        self.failIf(hasattr(wrapper, 'attr'))
+
+    def test_selective_update(self):
+        def f():
+            pass
+        f.attr = 'This is a different test'
+        f.dict_attr = dict(a=1, b=2, c=3)
+        def add_dict_attr(f):
+            f.dict_attr = {}
+            return f
+        assign = ('attr',)
+        update = ('dict_attr',)
+        @functools.wraps(f, assign, update)
+        @add_dict_attr
+        def wrapper():
+            pass
+        self.check_wrapper(wrapper, f, assign, update)
+        self.assertEqual(wrapper.__name__, 'wrapper')
+        self.assertEqual(wrapper.__doc__, None)
+        self.assertEqual(wrapper.attr, 'This is a different test')
+        self.assertEqual(wrapper.dict_attr, f.dict_attr)
+
 
 
 def test_main(verbose=None):
@@ -160,6 +267,8 @@ def test_main(verbose=None):
         TestPartial,
         TestPartialSubclass,
         TestPythonPartial,
+        TestUpdateWrapper,
+        TestWraps
     )
     test_support.run_unittest(*test_classes)