Add dependencies attribute to declarative and dynamic containers (#359)

* Add .dependencies attribute to declarative and dynamic containers

* Update changelog

* Add typing tests

docs/main/changelog.rst

@@ -7,6 +7,13 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+Development version
+-------------------
+- Add ``.dependencies`` attribute to the ``DeclarativeContainer`` and ``DynamicContainer``.
+  It returns dictionary of container ``Dependency`` and ``DependenciesContainer`` providers.
+  See issue `#357 <https://github.com/ets-labs/python-dependency-injector/issues/357>`_.
+  Many thanks to `Shaun Cutts <https://github.com/shaunc>`_ for suggesting the feature.
+
 4.8.3
 -----
 - Fix a bug in the ``Configuration`` provider to correctly handle overriding by ``None``.

src/dependency_injector/containers.pyi

@@ -24,6 +24,7 @@ C_Overriding = TypeVar('C_Overriding', bound='DeclarativeContainer')
 class Container:
     provider_type: Type[Provider] = Provider
     providers: Dict[str, Provider]
+    dependencies: Dict[str, Provider]
     overridden: Tuple[Provider]
     __self__: Provider
     def __init__(self) -> None: ...

src/dependency_injector/containers.pyx

@@ -15,6 +15,8 @@ from .providers cimport (
     Provider,
     Object,
     Resource,
+    Dependency,
+    DependenciesContainer,
     Container as ContainerProvider,
     deepcopy,
 )
@@ -125,6 +127,22 @@ class DynamicContainer(object):
             del self.providers[name]
         super(DynamicContainer, self).__delattr__(name)
 
+    @property
+    def dependencies(self):
+        """Return dependency providers dictionary.
+
+        Dependency providers can be both of :py:class:`dependency_injector.providers.Dependency` and
+        :py:class:`dependency_injector.providers.DependenciesContainer`.
+
+        :rtype:
+            dict[str, :py:class:`dependency_injector.providers.Provider`]
+        """
+        return {
+            name: provider
+            for name, provider in self.providers.items()
+            if isinstance(provider, (Dependency, DependenciesContainer))
+        }
+
     def set_providers(self, **providers):
         """Set container providers.
 
@@ -340,6 +358,22 @@ class DeclarativeContainerMetaClass(type):
             del cls.cls_providers[name]
         super(DeclarativeContainerMetaClass, cls).__delattr__(name)
 
+    @property
+    def dependencies(cls):
+        """Return dependency providers dictionary.
+
+        Dependency providers can be both of :py:class:`dependency_injector.providers.Dependency` and
+        :py:class:`dependency_injector.providers.DependenciesContainer`.
+
+        :rtype:
+            dict[str, :py:class:`dependency_injector.providers.Provider`]
+        """
+        return {
+            name: provider
+            for name, provider in cls.providers.items()
+            if isinstance(provider, (Dependency, DependenciesContainer))
+        }
+
 
 @six.add_metaclass(DeclarativeContainerMetaClass)
 class DeclarativeContainer(object):

tests/typing/declarative_container.py

@@ -1,3 +1,5 @@
+from typing import Dict
+
 from dependency_injector import containers, providers
 
 
@@ -38,3 +40,11 @@ class Container4(containers.DeclarativeContainer):
 
 container4 = Container4()
 container4.override(Container4())
+
+
+# Test 5: to check .dependencies attribute
+class Container5(containers.DeclarativeContainer):
+    provider = providers.Factory(int)
+
+
+dependencies: Dict[str, providers.Provider] = Container5.dependencies

tests/typing/dynamic_container.py

@@ -1,3 +1,5 @@
+from typing import Dict
+
 from dependency_injector import containers, providers
 
 
@@ -16,3 +18,7 @@ container3.override_providers(a=providers.Provider())
 # Test 4: to check set_providers()
 container4 = containers.DynamicContainer()
 container4.set_providers(a=providers.Provider())
+
+# Test 5: to check .dependencies attribute
+container5 = containers.DynamicContainer()
+dependencies: Dict[str, providers.Provider] = container5.dependencies

tests/unit/containers/test_declarative_py2_py3.py

@@ -60,6 +60,32 @@ class DeclarativeContainerTests(unittest.TestCase):
                               p21=ContainerB.p21,
                               p22=ContainerB.p22))
 
+    def test_dependencies_attribute(self):
+        class ContainerD(ContainerC):
+            p41 = providers.Dependency()
+            p42 = providers.DependenciesContainer()
+
+        class ContainerE(ContainerD):
+            p51 = providers.Dependency()
+            p52 = providers.DependenciesContainer()
+
+        self.assertEqual(
+            ContainerD.dependencies,
+            {
+                'p41': ContainerD.p41,
+                'p42': ContainerD.p42,
+            },
+        )
+        self.assertEqual(
+            ContainerE.dependencies,
+            {
+                'p41': ContainerD.p41,
+                'p42': ContainerD.p42,
+                'p51': ContainerE.p51,
+                'p52': ContainerE.p52,
+            },
+        )
+
     def test_set_get_del_providers(self):
         a_p13 = providers.Provider()
         b_p23 = providers.Provider()

tests/unit/containers/test_dynamic_py2_py3.py

@@ -24,6 +24,12 @@ class DeclarativeContainerInstanceTests(unittest.TestCase):
         self.assertIsNot(container_a1.p12, container_a2.p12)
         self.assertNotEqual(container_a1.providers, container_a2.providers)
 
+    def test_dependencies_attribute(self):
+        container = ContainerA()
+        container.a1 = providers.Dependency()
+        container.a2 = providers.DependenciesContainer()
+        self.assertEqual(container.dependencies, {'a1': container.a1, 'a2': container.a2})
+
     def test_set_get_del_providers(self):
         p13 = providers.Provider()