unittest: help with setUpClass not being a classmethod

pytest_django/plugin.py

@@ -41,6 +41,8 @@
 CONFIGURATION_ENV = 'DJANGO_CONFIGURATION'
 INVALID_TEMPLATE_VARS_ENV = 'FAIL_INVALID_TEMPLATE_VARS'
 
+PY2 = sys.version_info[0] == 2
+
 
 # ############### pytest hooks ################
 
@@ -258,7 +260,7 @@ def pytest_configure():
     _setup_django()
 
 
-def _method_is_defined_at_leaf(cls, method_name):
+def _classmethod_is_defined_at_leaf(cls, method_name):
     super_method = None
 
     for base_cls in cls.__bases__:
@@ -268,7 +270,15 @@ def _method_is_defined_at_leaf(cls, method_name):
     assert super_method is not None, (
         '%s could not be found in base class' % method_name)
 
-    return getattr(cls, method_name).__func__ is not super_method.__func__
+    method = getattr(cls, method_name)
+
+    try:
+        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):
+        pytest.fail('%s.%s should be a classmethod' % (cls, method_name))
+    return f is not super_method.__func__
 
 
 _disabled_classmethods = {}
@@ -280,9 +290,9 @@ def _disable_class_methods(cls):
 
     _disabled_classmethods[cls] = (
         cls.setUpClass,
-        _method_is_defined_at_leaf(cls, 'setUpClass'),
+        _classmethod_is_defined_at_leaf(cls, 'setUpClass'),
         cls.tearDownClass,
-        _method_is_defined_at_leaf(cls, 'tearDownClass'),
+        _classmethod_is_defined_at_leaf(cls, 'tearDownClass'),
     )
 
     cls.setUpClass = types.MethodType(lambda cls: None, cls)

tests/test_unittest.py

@@ -122,6 +122,25 @@ def test_pass(self):
         ])
         assert result.ret == 0
 
+    def test_setUpClass_not_being_a_classmethod(self, django_testdir):
+        django_testdir.create_test_module('''
+            from django.test import TestCase
+
+            class TestFoo(TestCase):
+                def setUpClass(self):
+                    pass
+
+                def test_pass(self):
+                    pass
+        ''')
+
+        result = django_testdir.runpytest_subprocess('-v', '-s')
+        result.stdout.fnmatch_lines([
+            "* ERROR at setup of TestFoo.test_pass *",
+            "E *Failed: <class 'tpkg.test_the_test.TestFoo'>.setUpClass should be a classmethod",  # noqa:E501
+        ])
+        assert result.ret == 1
+
     def test_multi_inheritance_setUpClass(self, django_testdir):
         django_testdir.create_test_module('''
             from django.test import TestCase