Singleton.full_reset() (#391)

* Improve .traverse() typing stubs

* Fix container.reset_singletons()

* Add implementation, tests, and typing stubs

* Add docs and example

* Update changelog

Author: rmk135

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 ``singleton.full_reset()`` method to reset all underlying singleton providers.
+- Fix ``container.reset_singleton()`` to reset all provider types, not only ``Singleton``.
+- Improve ``container.traverse(types=[...])`` and ``provider.traverse(types=[...])`` typing stubs
+  to return ``types`` -typed iterator.
+
 4.18.0
 ------
 - Add ``container.reset_singleton()`` method to reset container singletons.

docs/providers/singleton.rst

@@ -54,6 +54,14 @@ provider.
    Resetting of the memorized object clears the reference to it. Further object's lifecycle is
    managed by the garbage collector.
 
+Method ``.reset()`` resets only current provider. To reset all dependent singleton providers
+call ``.full_reset()`` method.
+
+.. literalinclude:: ../../examples/providers/singleton_full_resetting.py
+   :language: python
+   :lines: 3-
+   :emphasize-lines: 25
+
 Using singleton with multiple threads
 -------------------------------------
 

examples/providers/singleton_full_resetting.py

@@ -0,0 +1,31 @@
+"""`Singleton` provider full resetting example."""
+
+from dependency_injector import containers, providers
+
+
+class Database:
+    ...
+
+
+class UserService:
+    def __init__(self, db: Database):
+        self.db = db
+
+
+class Container(containers.DeclarativeContainer):
+
+    database = providers.Singleton(Database)
+
+    user_service = providers.Singleton(UserService, db=database)
+
+
+if __name__ == '__main__':
+    container = Container()
+
+    user_service1 = container.user_service()
+
+    container.user_service.full_reset()
+
+    user_service2 = container.user_service()
+    assert user_service2 is not user_service1
+    assert user_service2.db is not user_service1.db

examples/providers/singleton_resetting.py

@@ -9,15 +9,15 @@ class UserService:
 
 class Container(containers.DeclarativeContainer):
 
-    user_service_provider = providers.Singleton(UserService)
+    user_service = providers.Singleton(UserService)
 
 
 if __name__ == '__main__':
     container = Container()
 
-    user_service1 = container.user_service_provider()
+    user_service1 = container.user_service()
 
-    container.user_service_provider.reset()
+    container.user_service.reset()
 
-    user_service2 = container.user_service_provider()
+    user_service2 = container.user_service()
     assert user_service2 is not user_service1

src/dependency_injector/containers.c

@@ -21,6 +21,7 @@ from .providers import Provider
 C_Base = TypeVar('C_Base', bound='Container')
 C = TypeVar('C', bound='DeclarativeContainer')
 C_Overriding = TypeVar('C_Overriding', bound='DeclarativeContainer')
+TT = TypeVar('TT')
 
 
 class Container:
@@ -46,10 +47,10 @@ class Container:
     def apply_container_providers_overridings(self) -> None: ...
     def reset_singletons(self) -> None: ...
     @overload
-    def traverse(self, types: Optional[Sequence[Type]] = None) -> Iterator[Provider]: ...
+    def traverse(self, types: Optional[Sequence[TT]] = None) -> Iterator[TT]: ...
     @classmethod
     @overload
-    def traverse(cls, types: Optional[Sequence[Type]] = None) -> Iterator[Provider]: ...
+    def traverse(cls, types: Optional[Sequence[TT]] = None) -> Iterator[TT]: ...
 
 
 class DynamicContainer(Container): ...

src/dependency_injector/containers.pyi

@@ -272,8 +272,8 @@ class DynamicContainer(Container):
             provider.apply_overridings()
 
     def reset_singletons(self):
-        """Reset all container singletons."""
-        for provider in self.traverse(types=[providers.Singleton]):
+        """Reset container singletons."""
+        for provider in self.traverse(types=[providers.BaseSingleton]):
             provider.reset()