From a2fb095e6909504a38077db26156319611106c93 Mon Sep 17 00:00:00 2001
From: Roman Mogylatov <rmogilatov@gmail.com>
Date: Wed, 26 Aug 2020 21:18:03 -0400
Subject: [PATCH] Add types module for explicit provider typing

---
 src/dependency_injector/providers.pyi | 5 ++++-
 src/dependency_injector/types.py      | 9 +++++++++
 tests/typing/factory.py               | 6 +++++-
 3 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 src/dependency_injector/types.py

diff --git a/src/dependency_injector/providers.pyi b/src/dependency_injector/providers.pyi
index 2eff0333..0617e8f2 100644
--- a/src/dependency_injector/providers.pyi
+++ b/src/dependency_injector/providers.pyi
@@ -14,6 +14,9 @@ from typing import (
     Coroutine as _Coroutine,
 )
 
+from .types import Provider as _Provider
+
+
 Injection = Any
 T = TypeVar('T')
 
@@ -24,7 +27,7 @@ class OverridingContext:
     def __exit__(self, *_: Any) -> None: ...
 
 
-class Provider:
+class Provider(_Provider):
     def __init__(self) -> None: ...
     def __call__(self, *args: Injection, **kwargs: Injection) -> Any: ...
     def __deepcopy__(self, memo: Optional[Dict[str, Any]]) -> Provider: ...
diff --git a/src/dependency_injector/types.py b/src/dependency_injector/types.py
new file mode 100644
index 00000000..f60c4b03
--- /dev/null
+++ b/src/dependency_injector/types.py
@@ -0,0 +1,9 @@
+from typing import TypeVar, Generic, Any
+
+
+Injection = Any
+T = TypeVar('T')
+
+
+class Provider(Generic[T]):
+    def __call__(self, *args: Injection, **kwargs: Injection) -> T: ...
diff --git a/tests/typing/factory.py b/tests/typing/factory.py
index 86876bef..026e113a 100644
--- a/tests/typing/factory.py
+++ b/tests/typing/factory.py
@@ -1,6 +1,6 @@
 from typing import Tuple, Any, Dict
 
-from dependency_injector import providers
+from dependency_injector import providers, types
 
 
 class Animal:
@@ -62,3 +62,7 @@ provider9 = providers.FactoryAggregate(
 factory_a_9: providers.Factory = provider9.a
 factory_b_9: providers.Factory = provider9.b
 val9: Any = provider9('a')
+
+# Test 10: to check the explicit typing
+factory10: types.Provider[Animal] = providers.Factory(Cat)
+animal10: Animal = factory10()