Add support for Fast Stream Depends (#898)

Author: AndrianEquestrian

docs/examples/fastdepends.rst

@@ -0,0 +1,48 @@
+.. _fastdepends-example:
+
+FastDepends example
+===================
+
+.. meta::
+   :keywords: Python,Dependency Injection,FastDepends,Example
+   :description: This example demonstrates a usage of the FastDepends and Dependency Injector.
+
+
+This example demonstrates how to use ``Dependency Injector`` with `FastDepends <https://github.com/Lancetnik/FastDepends>`_, a lightweight dependency injection framework inspired by FastAPI's dependency system, but without the web framework components.
+
+Basic Usage
+-----------
+
+The integration between FastDepends and Dependency Injector is straightforward. Simply use Dependency Injector's ``Provide`` marker within FastDepends' ``Depends`` function:
+
+.. code-block:: python
+
+    import sys
+
+    from dependency_injector import containers, providers
+    from dependency_injector.wiring import inject, Provide
+    from fast_depends import Depends
+
+
+    class CoefficientService:
+        @staticmethod
+        def get_coefficient() -> float:
+            return 1.2
+
+
+    class Container(containers.DeclarativeContainer):
+        service = providers.Factory(CoefficientService)
+
+
+    @inject
+    def apply_coefficient(
+        a: int,
+        coefficient_provider: CoefficientService = Depends(Provide[Container.service]),
+    ) -> float:
+        return a * coefficient_provider.get_coefficient()
+
+
+    container = Container()
+    container.wire(modules=[sys.modules[__name__]])
+
+    apply_coefficient(100) == 120.0

docs/examples/index.rst

@@ -22,5 +22,6 @@ Explore the examples to see the ``Dependency Injector`` in action.
     fastapi
     fastapi-redis
     fastapi-sqlalchemy
+    fastdepends
 
 .. disqus::

docs/wiring.rst

@@ -693,5 +693,6 @@ Take a look at other application examples:
 - :ref:`fastapi-example`
 - :ref:`fastapi-redis-example`
 - :ref:`fastapi-sqlalchemy-example`
+- :ref:`fastdepends-example`
 
 .. disqus::

requirements-dev.txt

@@ -20,5 +20,6 @@ scipy
 boto3
 mypy_boto3_s3
 typing_extensions
+fast-depends
 
 -r requirements-ext.txt

src/dependency_injector/wiring.py

@@ -59,10 +59,33 @@ def get_origin(tp):
             return None
 
 
+MARKER_EXTRACTORS = []
+
 try:
-    import fastapi.params
+    from fastapi.params import Depends as FastAPIDepends
 except ImportError:
-    fastapi = None
+    pass
+else:
+
+    def extract_marker_from_fastapi(param: Any) -> Any:
+        if isinstance(param, FastAPIDepends):
+            return param.dependency
+        return None
+
+    MARKER_EXTRACTORS.append(extract_marker_from_fastapi)
+
+try:
+    from fast_depends.dependencies import Depends as FastDepends
+except ImportError:
+    pass
+else:
+
+    def extract_marker_from_fast_depends(param: Any) -> Any:
+        if isinstance(param, FastDepends):
+            return param.dependency
+        return None
+
+    MARKER_EXTRACTORS.append(extract_marker_from_fast_depends)
 
 
 try:
@@ -76,8 +99,7 @@ def get_origin(tp):
 except ImportError:
     werkzeug = None
 
-
-from . import providers
+from . import providers  # noqa: E402
 
 __all__ = (
     "wire",
@@ -607,14 +629,13 @@ def _extract_marker(parameter: inspect.Parameter) -> Optional["_Marker"]:
     else:
         marker = parameter.default
 
-    if not isinstance(marker, _Marker) and not _is_fastapi_depends(marker):
-        return None
-
-    if _is_fastapi_depends(marker):
-        marker = marker.dependency
+    for marker_extractor in MARKER_EXTRACTORS:
+        if _marker := marker_extractor(marker):
+            marker = _marker
+            break
 
-        if not isinstance(marker, _Marker):
-            return None
+    if not isinstance(marker, _Marker):
+        return None
 
     return marker
 
@@ -735,10 +756,6 @@ def _get_patched(
     return patched
 
 
-def _is_fastapi_depends(param: Any) -> bool:
-    return fastapi and isinstance(param, fastapi.params.Depends)
-
-
 def _is_patched(fn) -> bool:
     return _patched_registry.has_callable(fn)
 

tests/unit/samples/wiringfastdepends/sample.py

@@ -0,0 +1,39 @@
+import sys
+
+from fast_depends import Depends
+from typing_extensions import Annotated
+
+from dependency_injector import containers, providers
+from dependency_injector.wiring import Provide, inject
+
+
+class CoefficientService:
+    @staticmethod
+    def get_coefficient() -> float:
+        return 1.2
+
+
+class Container(containers.DeclarativeContainer):
+    service = providers.Factory(CoefficientService)
+
+
+@inject
+def apply_coefficient(
+    a: int,
+    coefficient_provider: CoefficientService = Depends(Provide[Container.service]),
+) -> float:
+    return a * coefficient_provider.get_coefficient()
+
+
+@inject
+def apply_coefficient_annotated(
+    a: int,
+    coefficient_provider: Annotated[
+        CoefficientService, Depends(Provide[Container.service])
+    ],
+) -> float:
+    return a * coefficient_provider.get_coefficient()
+
+
+container = Container()
+container.wire(modules=[sys.modules[__name__]])

tests/unit/wiring/test_fastdepends.py

@@ -0,0 +1,9 @@
+from wiringfastdepends import sample
+
+
+def test_apply_coefficient() -> None:
+    assert sample.apply_coefficient(100) == 120.0
+
+
+def test_apply_coefficient_annotated() -> None:
+    assert sample.apply_coefficient_annotated(100) == 120.0

tox.ini

@@ -17,6 +17,7 @@ deps=
     mypy_boto3_s3
     pydantic-settings
     werkzeug
+    fast-depends
 extras=
     yaml
 commands = pytest
@@ -44,6 +45,7 @@ deps =
     boto3
     mypy_boto3_s3
     werkzeug
+    fast-depends
 commands = pytest -m pydantic
 
 [testenv:coveralls]