Add simple FastAPI example

docs/main/changelog.rst

@@ -7,6 +7,10 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+Develop
+-------
+- Add simple ``FastAPI`` example.
+
 4.4.1
 -----
 - Improve ``FastAPI`` integration: handle ``Depends(Provide[...])``.

examples/miniapps/fastapi-simple/fastapi_di_example.py

@@ -0,0 +1,29 @@
+import sys
+
+from fastapi import FastAPI, Depends
+from dependency_injector import containers, providers
+from dependency_injector.wiring import inject, Provide
+
+
+class Service:
+    async def process(self) -> str:
+        return 'Ok'
+
+
+class Container(containers.DeclarativeContainer):
+
+    service = providers.Factory(Service)
+
+
+app = FastAPI()
+
+
+@app.api_route('/')
+@inject
+async def index(service: Service = Depends(Provide[Container.service])):
+    result = await service.process()
+    return {'result': result}
+
+
+container = Container()
+container.wire(modules=[sys.modules[__name__]])

examples/miniapps/fastapi-simple/tests.py

@@ -0,0 +1,25 @@
+from unittest import mock
+
+import pytest
+from httpx import AsyncClient
+
+from fastapi_di_example import app, container, Service
+
+
+@pytest.fixture
+def client(event_loop):
+    client = AsyncClient(app=app, base_url='http://test')
+    yield client
+    event_loop.run_until_complete(client.aclose())
+
+
+@pytest.mark.asyncio
+async def test_index(client):
+    service_mock = mock.AsyncMock(spec=Service)
+    service_mock.process.return_value = 'Foo'
+
+    with container.service.override(service_mock):
+        response = await client.get('/')
+
+    assert response.status_code == 200
+    assert response.json() == {'result': 'Foo'}