Allow explicit typing on Selector using TypeVar with default Any (#932)

Author: leonarduschen

pyproject.toml

@@ -55,7 +55,8 @@ dynamic = ["version"]
 dependencies = [
     # typing.Annotated since v3.9
     # typing.Self and typing.assert_never since v3.11
-    "typing-extensions; python_version<'3.11'",
+    # typing.TypeVar default since v3.13
+    "typing-extensions; python_version<'3.13'",
 ]
 
 [project.optional-dependencies]

src/dependency_injector/providers.pyi

@@ -4,7 +4,6 @@ from contextlib import AbstractContextManager, AbstractAsyncContextManager
 from pathlib import Path
 from typing import (
     Awaitable,
-    TypeVar,
     Generic,
     Type,
     Callable as _Callable,
@@ -22,6 +21,8 @@ from typing import (
     overload,
 )
 
+from typing_extensions import Self as _Self, TypeVar
+
 try:
     import yaml
 except ImportError:
@@ -38,6 +39,7 @@ Injection = Any
 ProviderParent = Union["Provider", Any]
 T = TypeVar("T")
 TT = TypeVar("TT")
+T_Any = TypeVar("T_Any", default=Any)
 P = TypeVar("P", bound="Provider")
 BS = TypeVar("BS", bound="BaseSingleton")
 
@@ -542,17 +544,17 @@ class Container(Provider[T]):
     def parent_name(self) -> Optional[str]: ...
     def assign_parent(self, parent: ProviderParent) -> None: ...
 
-class Selector(Provider[Any]):
+class Selector(Provider[T_Any]):
     def __init__(
         self, selector: Optional[_Callable[..., Any]] = None, **providers: Provider
     ): ...
-    def __getattr__(self, name: str) -> Provider: ...
+    def __getattr__(self, name: str) -> Provider[T_Any]: ...
     @property
     def selector(self) -> Optional[_Callable[..., Any]]: ...
-    def set_selector(self, selector: Optional[_Callable[..., Any]]) -> Selector: ...
+    def set_selector(self, selector: Optional[_Callable[..., Any]]) -> _Self: ...
     @property
-    def providers(self) -> _Dict[str, Provider]: ...
-    def set_providers(self, **providers: Provider) -> Selector: ...
+    def providers(self) -> _Dict[str, Provider[T_Any]]: ...
+    def set_providers(self, **providers: Provider) -> _Self: ...
 
 class ProvidedInstanceFluentInterface:
     def __getattr__(self, item: Any) -> AttributeGetter: ...

tests/typing/selector.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Callable, Optional, Dict
 
 from dependency_injector import providers
 
@@ -40,3 +40,36 @@
 async def _async4() -> None:
     var1: Any = await provider4()
     var2: Any = await provider4.async_()
+
+
+# Test 5: to check selector getter and setter
+provider5 = providers.Selector(
+    lambda: "a",
+    a=providers.Factory(object),
+    b=providers.Factory(object),
+)
+selector5: Optional[Callable[..., Any]] = provider5.selector
+provider5_after_set_selector: providers.Selector[Any] = provider5.set_selector(lambda: "a")
+
+# Test 6: to check providers getter and setter
+provider6 = providers.Selector(
+    lambda: "a",
+    a=providers.Factory(object),
+    b=providers.Factory(object),
+)
+providers6: Dict[str, providers.Provider[Any]] = provider6.providers
+provider6_after_set_providers: providers.Selector[Any] = provider6.set_providers(c=providers.Factory(object))
+
+
+# Test 7: to check explicit typing: return type, getattr, getter/setter of providers and selectors
+provider7 = providers.Selector[bool](lambda: "a", a=providers.Factory(bool), b=providers.Factory(int))
+var7: bool = provider7()
+attr7: providers.Provider[bool] = provider7.a
+
+selector7: Optional[Callable[..., Any]] = provider7.selector
+provider7_after_set_selector: providers.Selector[bool] = provider7.set_selector(lambda: "a")
+
+providers7: Dict[str, providers.Provider[bool]] = provider7.providers
+provider7_after_set_providers: providers.Selector[bool] = provider7.set_providers(
+    c=providers.Factory(str)
+)  # We don't require Provider of subclass of bool yet since Provider is invariant