Clean up DependenciesContainer provider and add tests

src/dependency_injector/providers.pyi

@@ -124,9 +124,9 @@ class DependenciesContainer(Object):
     def providers(self) -> _Dict[str, Provider]: ...
     def resolve_provider_name(self, provider: Provider) -> str: ...
     @property
-    def parent_name(self) -> str: ...
+    def parent(self) -> Optional[ProviderParent]: ...
     @property
-    def parent(self) -> ProviderParent: ...
+    def parent_name(self) -> Optional[str]: ...
     def assign_parent(self, parent: ProviderParent) -> None: ...
 
 

src/dependency_injector/providers.pyx

@@ -833,12 +833,11 @@ cdef class DependenciesContainer(Object):
 
     def __init__(self, **dependencies):
         """Initializer."""
-        self.__providers = dependencies
-
-        for provider in dependencies.items():
+        for provider in dependencies.values():
             if isinstance(provider, (Dependency, DependenciesContainer, Container)):
                 provider.assign_parent(self)
 
+        self.__providers = dependencies
         self.__parent = None
 
         super(DependenciesContainer, self).__init__(None)
@@ -857,14 +856,7 @@ cdef class DependenciesContainer(Object):
         copied.__provides = deepcopy(self.__provides, memo)
         copied.__providers = deepcopy(self.__providers, memo)
 
-        # TODO: remove duplication
-        copied_parent = (
-            deepcopy(self.__parent, memo)
-            if is_provider(self.parent) or is_container_instance(self.parent)
-            else self.parent
-        )
-        copied.assign_parent(copied_parent)
-
+        self._copy_parent(copied, memo)
         self._copy_overridings(copied, memo)
 
         return copied
@@ -943,27 +935,37 @@ cdef class DependenciesContainer(Object):
 
     def resolve_provider_name(self, provider):
         """Try to resolve provider name."""
-        # TODO: add tests
         for provider_name, container_provider in self.providers.items():
             if container_provider is provider:
                 return provider_name
         else:
             raise Error(f'Can not resolve name for provider "{provider}"')
 
-    @property
-    def parent_name(self):
-        """Return parent name."""
-        return f'{self.parent.parent_name}.{self.parent.resolve_provider_name(self)}'
-
     @property
     def parent(self):
         """Return parent."""
         return self.__parent
 
+    @property
+    def parent_name(self):
+        """Return parent name."""
+        if not self.__parent:
+            return None
+
+        name = ''
+        if self.__parent.parent_name:
+            name += f'{self.__parent.parent_name}.'
+        name += f'{self.__parent.resolve_provider_name(self)}'
+
+        return name
+
     def assign_parent(self, parent):
         """Assign parent."""
         self.__parent = parent
 
+    def _copy_parent(self, copied, memo):
+        _copy_parent(self, copied, memo)
+
     cpdef object _override_providers(self, object container):
         """Override providers with providers from provided container."""
         for name, dependency_provider in container.providers.items():

tests/unit/providers/test_base_py2_py3.py

@@ -459,7 +459,17 @@ class DependencyTests(unittest.TestCase):
         container.name = provider
         self.assertEqual(provider.parent_name, 'name')
 
-    def test_deepcopy_parent(self):
+    def test_parent_name_with_deep_parenting(self):
+        provider = providers.Dependency()
+        container = providers.DependenciesContainer(name=provider)
+        _ = providers.DependenciesContainer(container=container)
+        self.assertEqual(provider.parent_name, 'container.name')
+
+    def test_parent_name_is_none(self):
+        provider = providers.DependenciesContainer()
+        self.assertIsNone(provider.parent_name)
+
+    def test_parent_deepcopy(self):
         container = containers.DynamicContainer()
         provider = providers.Dependency()
         container.name = provider
@@ -633,3 +643,63 @@ class DependenciesContainerTests(unittest.TestCase):
 
         self.assertFalse(dependency.overridden)
         self.assertFalse(dependency.overridden)
+
+    def test_assign_parent(self):
+        parent = providers.DependenciesContainer()
+        provider = providers.DependenciesContainer()
+
+        provider.assign_parent(parent)
+
+        self.assertIs(provider.parent, parent)
+
+    def test_parent_name(self):
+        container = containers.DynamicContainer()
+        provider = providers.DependenciesContainer()
+        container.name = provider
+        self.assertEqual(provider.parent_name, 'name')
+
+    def test_parent_name_with_deep_parenting(self):
+        provider = providers.DependenciesContainer()
+        container = providers.DependenciesContainer(name=provider)
+        _ = providers.DependenciesContainer(container=container)
+        self.assertEqual(provider.parent_name, 'container.name')
+
+    def test_parent_name_is_none(self):
+        provider = providers.DependenciesContainer()
+        self.assertIsNone(provider.parent_name)
+
+    def test_parent_deepcopy(self):
+        container = containers.DynamicContainer()
+        provider = providers.DependenciesContainer()
+        container.name = provider
+
+        copied = providers.deepcopy(container)
+
+        self.assertIs(container.name.parent, container)
+        self.assertIs(copied.name.parent, copied)
+
+        self.assertIsNot(container, copied)
+        self.assertIsNot(container.name, copied.name)
+        self.assertIsNot(container.name.parent, copied.name.parent)
+
+    def test_parent_set_on__getattr__(self):
+        provider = providers.DependenciesContainer()
+        self.assertIsInstance(provider.name, providers.Dependency)
+        self.assertIs(provider.name.parent, provider)
+
+    def test_parent_set_on__init__(self):
+        provider = providers.Dependency()
+        container = providers.DependenciesContainer(name=provider)
+        self.assertIs(container.name, provider)
+        self.assertIs(container.name.parent, container)
+
+    def test_resolve_provider_name(self):
+        container = providers.DependenciesContainer()
+        self.assertEqual(container.resolve_provider_name(container.name), 'name')
+
+    def test_resolve_provider_name_no_provider(self):
+        provider = providers.Dependency()
+        container = providers.DependenciesContainer()
+
+        with self.assertRaises(errors.Error):
+            container.resolve_provider_name(provider)