Add tests for invalid type of marker

src/dependency_injector/wiring.py

@@ -550,7 +550,7 @@ def _is_method(member):
 
 
 def _is_marker(member):
-    return isinstance(member, Provide) or isinstance(member, Provider)
+    return isinstance(member, _Marker)
 
 
 def _get_patched(fn, reference_injections, reference_closing):

tests/unit/samples/wiringsamples/module_invalid_attr_injection.py

@@ -0,0 +1,8 @@
+"""Test module for wiring with invalid type of marker for attribute injection."""
+
+from dependency_injector.wiring import Closing
+
+from .container import Container
+
+
+service = Closing[Container.service]

tests/unit/wiring/test_wiring_py36.py

@@ -70,6 +70,15 @@ class WiringTest(unittest.TestCase):
         self.assertIsInstance(module.service_provider(), Service)
         self.assertIsInstance(module.undefined, Provide)
 
+    def test_module_attribute_wiring_with_invalid_marker(self):
+        from wiringsamples import module_invalid_attr_injection
+        with self.assertRaises(Exception) as context:
+            self.container.wire(modules=[module_invalid_attr_injection])
+        self.assertEqual(
+            str(context.exception),
+            'Unknown type of marker {0}'.format(module_invalid_attr_injection.service),
+        )
+
     def test_class_wiring(self):
         test_class_object = module.TestClass()
         self.assertIsInstance(test_class_object.service, Service)