Fix classmethod test

This test was incorrect in the case where the method was inherited from a
subclass.  Which ironically is precisely what the function was supposed to
test.

Additionally, there was a problem where the restored methods were bound to
the wrong class.  Added test case and fixed that also.

Fixes #597

Author: Martijn van Oosterhout

docs/changelog.rst

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+unreleased
+----------
+
+* Fix test for classmethod with Django TestCases (#597, #598).
+
 3.2.1
 -----
 

pytest_django/plugin.py

@@ -277,7 +277,9 @@ def _classmethod_is_defined_at_leaf(cls, method_name):
         f = method.__func__
     except AttributeError:
         pytest.fail('%s.%s should be a classmethod' % (cls, method_name))
-    if PY2 and not (inspect.ismethod(method) and method.__self__ is cls):
+    if PY2 and not (inspect.ismethod(method) and
+                    inspect.isclass(method.__self__) and
+                    issubclass(cls, method.__self__)):
         pytest.fail('%s.%s should be a classmethod' % (cls, method_name))
     return f is not super_method.__func__
 
@@ -290,9 +292,11 @@ def _disable_class_methods(cls):
         return
 
     _disabled_classmethods[cls] = (
-        cls.setUpClass,
+        # Get the classmethod object (not the resulting bound method),
+        # otherwise inheritence will be broken when restoring.
+        cls.__dict__.get('setUpClass'),
         _classmethod_is_defined_at_leaf(cls, 'setUpClass'),
-        cls.tearDownClass,
+        cls.__dict__.get('tearDownClass'),
         _classmethod_is_defined_at_leaf(cls, 'tearDownClass'),
     )
 

tests/test_unittest.py

@@ -141,6 +141,79 @@ def test_pass(self):
         ])
         assert result.ret == 1
 
+    def test_setUpClass_multiple_subclasses(self, django_testdir):
+        django_testdir.create_test_module('''
+            from django.test import TestCase
+
+
+            class TestFoo(TestCase):
+                @classmethod
+                def setUpClass(cls):
+                    super(TestFoo, cls).setUpClass()
+
+                def test_shared(self):
+                    pass
+
+
+            class TestBar(TestFoo):
+                def test_bar1(self):
+                    pass
+
+
+            class TestBar2(TestFoo):
+                def test_bar21(self):
+                    pass
+        ''')
+
+        result = django_testdir.runpytest_subprocess('-v', '-s')
+        result.stdout.fnmatch_lines([
+            "*TestFoo::test_shared Creating test database for*",
+            "PASSED",
+            "*TestBar::test_bar1 PASSED",
+            "*TestBar::test_shared PASSED",
+            "*TestBar2::test_bar21 PASSED",
+            "*TestBar2::test_shared PASSED*",
+        ])
+        assert result.ret == 0
+
+    def test_setUpClass_skip(self, django_testdir):
+        django_testdir.create_test_module('''
+            from django.test import TestCase
+            import pytest
+
+
+            class TestFoo(TestCase):
+                @classmethod
+                def setUpClass(cls):
+                    if cls is TestFoo:
+                        raise pytest.skip("Skip base class")
+                    super(TestFoo, cls).setUpClass()
+
+                def test_shared(self):
+                    pass
+
+
+            class TestBar(TestFoo):
+                def test_bar1(self):
+                    pass
+
+
+            class TestBar2(TestFoo):
+                def test_bar21(self):
+                    pass
+        ''')
+
+        result = django_testdir.runpytest_subprocess('-v', '-s')
+        result.stdout.fnmatch_lines([
+            "*TestFoo::test_shared Creating test database for*",
+            "SKIPPED",
+            "*TestBar::test_bar1 PASSED",
+            "*TestBar::test_shared PASSED",
+            "*TestBar2::test_bar21 PASSED",
+            "*TestBar2::test_shared PASSED*",
+        ])
+        assert result.ret == 0
+
     def test_multi_inheritance_setUpClass(self, django_testdir):
         django_testdir.create_test_module('''
             from django.test import TestCase