Introduce concept with annotations

src/dependency_injector/containers.pyi

@@ -17,6 +17,7 @@ class Container:
     def override_providers(self, **overriding_providers: Provider) -> None: ...
     def reset_last_overriding(self) -> None: ...
     def reset_override(self) -> None: ...
+    def resolve_provider_name(self, provider_to_resolve: Provider) -> Optional[str]: ...
     def wire(self, modules: Optional[Iterable[ModuleType]] = None, packages: Optional[Iterable[ModuleType]] = None) -> None: ...
 
 

src/dependency_injector/containers.pyx

@@ -57,6 +57,7 @@ class DynamicContainer(object):
         self.provider_type = Provider
         self.providers = dict()
         self.overridden = tuple()
+        self.declarative_parent = None
         super(DynamicContainer, self).__init__()
 
     def __deepcopy__(self, memo):
@@ -68,6 +69,7 @@ class DynamicContainer(object):
         copied = self.__class__()
         copied.provider_type = Provider
         copied.overridden = deepcopy(self.overridden, memo)
+        copied.declarative_parent = self.declarative_parent
 
         for name, provider in deepcopy(self.providers, memo).items():
             setattr(copied, name, provider)
@@ -179,6 +181,20 @@ class DynamicContainer(object):
         for provider in six.itervalues(self.providers):
             provider.reset_override()
 
+    def resolve_provider_name(self, provider_to_resolve):
+        """Try to resolve provider name by its instance."""
+        if self.declarative_parent:
+            provider_name = self.declarative_parent.resolve_provider_name(provider_to_resolve)
+            if provider_name:
+                return provider_name
+
+        for provider_name, container_provider in self.providers.items():
+            if container_provider is provider_to_resolve:
+                return provider_name
+        else:
+            return None
+
+
     def wire(self, modules=None, packages=None):
         """Wire container providers with provided packages and modules by name.
 
@@ -329,6 +345,7 @@ class DeclarativeContainer(object):
         """
         container = cls.instance_type()
         container.provider_type = cls.provider_type
+        container.declarative_parent = cls
         container.set_providers(**deepcopy(cls.providers))
         container.override_providers(**overriding_providers)
         return container
@@ -382,6 +399,15 @@ class DeclarativeContainer(object):
         for provider in six.itervalues(cls.providers):
             provider.reset_override()
 
+    @classmethod
+    def resolve_provider_name(cls, provider_to_resolve):
+        """Try to resolve provider name by its instance."""
+        for provider_name, container_provider in cls.providers.items():
+            if container_provider is provider_to_resolve:
+                return provider_name
+        else:
+            return None
+
     @classmethod
     def wire(cls, modules=None, packages=None):
         """Wire container providers with provided packages and modules by name.

src/dependency_injector/wiring.py

@@ -4,11 +4,12 @@ import functools
 import inspect
 import pkgutil
 from types import ModuleType
-from typing import Optional, Iterable, Callable, Any, Type, Dict
+from typing import Optional, Iterable, Callable, Any, Type, Dict, Generic, TypeVar
 
 from . import providers
 
 AnyContainer = Any
+T = TypeVar('T')
 
 
 def wire(
@@ -62,26 +63,41 @@ def _patch_fn(
 
 
 def _resolve_injections(fn: Callable[..., Any], container: AnyContainer) -> Dict[str, Any]:
-    signature = inspect.signature(fn)
-
     config = _resolve_container_config(container)
 
+    signature = inspect.signature(fn)
+
     injections = {}
     for parameter_name, parameter in signature.parameters.items():
-        if parameter_name in container.providers:
-            injections[parameter_name] = container.providers[parameter_name]
+        if not isinstance(parameter.default, _Marker):
+            continue
+        marker = parameter.default
 
-        if parameter_name.endswith('_provider'):
-            provider_name = parameter_name[:-9]
-            if provider_name in container.providers:
-                injections[parameter_name] = container.providers[provider_name].provider
+        provider = None
 
-        if config and isinstance(parameter.default, ConfigurationOption):
-            option_provider = config.get_option_provider(parameter.default.selector)
-            if parameter.annotation:
-                injections[parameter_name] = option_provider.as_(parameter.annotation)
-            else:
-                injections[parameter_name] = option_provider
+        provider_name = container.resolve_provider_name(marker.provider)
+        if provider_name:
+            provider = container.providers[provider_name]
+
+        if config and isinstance(marker.provider, providers.ConfigurationOption):
+            full_option_name = marker.provider.get_name()
+            _, *parts = full_option_name.split('.')
+            relative_option_name = '.'.join(parts)
+            provider = config.get_option_provider(relative_option_name)
+            if parameter.annotation is int:
+                provider = provider.as_int()
+            elif parameter.annotation is float:
+                provider = provider.as_float()
+            elif parameter.annotation is not inspect.Parameter.empty:
+                provider = provider.as_(parameter.annotation)
+
+        if provider is None:
+            continue
+
+        if isinstance(marker, Provide):
+            injections[parameter_name] = provider
+        elif isinstance(marker, Provider):
+            injections[parameter_name] = provider.provider
 
     return injections
 
@@ -118,18 +134,24 @@ def _patch_with_injections(fn, injections):
     return _patched
 
 
-class ConfigurationOptionMeta(type):
+class ClassGetItemMeta(type):
 
     def __getitem__(cls, item):
         # Spike for Python 3.6
         return cls(item)
 
 
-class ConfigurationOption(metaclass=ConfigurationOptionMeta):
-    """Configuration option marker."""
+class _Marker(Generic[T], metaclass=ClassGetItemMeta):
+    def __init__(self, provider: providers.Provider) -> None:
+        self.provider = provider
 
-    def __init__(self, selector: str):
-        self.selector = selector
-
-    def __class_getitem__(cls, item):
+    def __class_getitem__(cls, item) -> T:
         return cls(item)
+
+
+class Provide(_Marker):
+    ...
+
+
+class Provider(_Marker):
+    ...

tests/unit/wiring/container.py

@@ -0,0 +1,10 @@
+from dependency_injector import containers, providers
+
+from .service import Service
+
+
+class Container(containers.DeclarativeContainer):
+
+    config = providers.Configuration()
+
+    service = providers.Factory(Service)

tests/unit/wiring/module.py

@@ -1,24 +1,30 @@
 """Test module for wiring."""
 
-from dependency_injector.wiring import ConfigurationOption
+from typing import Callable
+
+from dependency_injector.wiring import Provide, Provider
+
+from .container import Container
+from .service import Service
 
 
 class TestClass:
 
-    def __init__(self, service):
+    def __init__(self, service: Service = Provide[Container.service]):
         self.service = service
 
 
-def test_function(service):
+def test_function(service: Service = Provide[Container.service]):
     return service
 
 
-def test_function_provider(service_provider):
-    return service_provider()
+def test_function_provider(service_provider: Callable[..., Service] = Provider[Container.service]):
+    service = service_provider()
+    return service
 
 
 def test_config_value(
-        some_value_int: int = ConfigurationOption['a.b.c'],
-        some_value_str: str = ConfigurationOption['a.b.c'],
+        some_value_int: int = Provide[Container.config.a.b.c],
+        some_value_str: str = Provide[Container.config.a.b.c],
 ):
     return some_value_int, some_value_str

tests/unit/wiring/package/subpackage/submodule.py

@@ -1,2 +1,8 @@
-def test_function(service):
+from dependency_injector.wiring import Provide
+
+from ...container import Container
+from ...service import Service
+
+
+def test_function(service: Service = Provide[Container.service]):
     return service

tests/unit/wiring/service.py

@@ -0,0 +1,2 @@
+class Service:
+    service_attr: int

tests/unit/wiring/test_wiring_py36.py

@@ -1,19 +1,9 @@
 import unittest
 
-from dependency_injector import containers, providers
 
 from . import module, package
-
-
-class Service:
-    ...
-
-
-class Container(containers.DeclarativeContainer):
-
-    config = providers.Configuration()
-
-    service = providers.Factory(Service)
+from .service import Service
+from .container import Container
 
 
 class WiringTest(unittest.TestCase):