Add tests for base providers

src/dependency_injector/providers/base.pyx

@@ -179,8 +179,6 @@ cdef class Provider(object):
     @cython.wraparound(False)
     cpdef object _call_last_overriding(self, tuple args, dict kwargs):
         """Call last overriding provider and return result."""
-        if self.__overridden_len == 0:
-            return None
         return  <object>self.__overridden[self.__overridden_len - 1](*args,
                                                                      **kwargs)
 

tests/unit/providers/test_base.py

@@ -80,6 +80,38 @@ class ProviderTests(unittest.TestCase):
 
         self.assertEqual(self.provider.overridden, tuple())
 
+    def test_deepcopy(self):
+        provider = providers.Provider()
+
+        provider_copy = providers.deepcopy(provider)
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider, providers.Provider)
+
+    def test_deepcopy_from_memo(self):
+        provider = providers.Provider()
+        provider_copy_memo = providers.Provider()
+
+        provider_copy = providers.deepcopy(
+            provider, memo={id(provider): provider_copy_memo})
+
+        self.assertIs(provider_copy, provider_copy_memo)
+
+    def test_deepcopy_overridden(self):
+        provider = providers.Provider()
+        overriding_provider = providers.Provider()
+
+        provider.override(overriding_provider)
+
+        provider_copy = providers.deepcopy(provider)
+        overriding_provider_copy = provider_copy.overridden[0]
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider, providers.Provider)
+
+        self.assertIsNot(overriding_provider, overriding_provider_copy)
+        self.assertIsInstance(overriding_provider_copy, providers.Provider)
+
     def test_repr(self):
         self.assertEqual(repr(self.provider),
                          '<dependency_injector.providers.base.'
@@ -102,6 +134,38 @@ class ObjectProviderTests(unittest.TestCase):
         provider.override(providers.Object(obj2))
         self.assertIs(provider(), obj2)
 
+    def test_deepcopy(self):
+        provider = providers.Object(1)
+
+        provider_copy = providers.deepcopy(provider)
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider, providers.Object)
+
+    def test_deepcopy_from_memo(self):
+        provider = providers.Object(1)
+        provider_copy_memo = providers.Provider()
+
+        provider_copy = providers.deepcopy(
+            provider, memo={id(provider): provider_copy_memo})
+
+        self.assertIs(provider_copy, provider_copy_memo)
+
+    def test_deepcopy_overridden(self):
+        provider = providers.Object(1)
+        overriding_provider = providers.Provider()
+
+        provider.override(overriding_provider)
+
+        provider_copy = providers.deepcopy(provider)
+        overriding_provider_copy = provider_copy.overridden[0]
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider, providers.Object)
+
+        self.assertIsNot(overriding_provider, overriding_provider_copy)
+        self.assertIsInstance(overriding_provider_copy, providers.Provider)
+
     def test_repr(self):
         some_object = object()
         provider = providers.Object(some_object)
@@ -161,6 +225,38 @@ class ExternalDependencyTests(unittest.TestCase):
     def test_call_not_overridden(self):
         self.assertRaises(errors.Error, self.provider)
 
+    def test_deepcopy(self):
+        provider = providers.ExternalDependency(int)
+
+        provider_copy = providers.deepcopy(provider)
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider, providers.ExternalDependency)
+
+    def test_deepcopy_from_memo(self):
+        provider = providers.ExternalDependency(int)
+        provider_copy_memo = providers.Provider()
+
+        provider_copy = providers.deepcopy(
+            provider, memo={id(provider): provider_copy_memo})
+
+        self.assertIs(provider_copy, provider_copy_memo)
+
+    def test_deepcopy_overridden(self):
+        provider = providers.ExternalDependency(int)
+        overriding_provider = providers.Provider()
+
+        provider.override(overriding_provider)
+
+        provider_copy = providers.deepcopy(provider)
+        overriding_provider_copy = provider_copy.overridden[0]
+
+        self.assertIsNot(provider, provider_copy)
+        self.assertIsInstance(provider, providers.ExternalDependency)
+
+        self.assertIsNot(overriding_provider, overriding_provider_copy)
+        self.assertIsInstance(overriding_provider_copy, providers.Provider)
+
     def test_repr(self):
         self.assertEqual(repr(self.provider),
                          '<dependency_injector.providers.base.'