migrate to modern-di (#31)

Author: lesnik512

app/__main__.py

@@ -1,11 +1,10 @@
 import granian
 from granian.constants import Interfaces, Loops
 
-from app import ioc
+from app.settings import settings
 
 
 if __name__ == "__main__":
-    settings = ioc.IOCContainer.settings.sync_resolve()
     granian.Granian(
         target="app.application:application",
         address="0.0.0.0",  # noqa: S104

app/api/decks.py

@@ -2,25 +2,20 @@
 
 import fastapi
 from advanced_alchemy.exceptions import NotFoundError
+from modern_di_fastapi import FromDI
 from sqlalchemy import orm
 from starlette import status
-from that_depends.providers import container_context
 
 from app import ioc, models, schemas
 from app.repositories import CardsService, DecksService
 
 
-async def init_di_context() -> typing.AsyncIterator[None]:
-    async with container_context():
-        yield
-
-
-ROUTER: typing.Final = fastapi.APIRouter(dependencies=[fastapi.Depends(init_di_context)])
+ROUTER: typing.Final = fastapi.APIRouter()
 
 
 @ROUTER.get("/decks/")
 async def list_decks(
-    decks_service: DecksService = fastapi.Depends(ioc.IOCContainer.decks_service),
+    decks_service: DecksService = FromDI(ioc.IOCContainer.decks_service),
 ) -> schemas.Decks:
     objects = await decks_service.list()
     return typing.cast(schemas.Decks, {"items": objects})
@@ -29,7 +24,7 @@ async def list_decks(
 @ROUTER.get("/decks/{deck_id}/")
 async def get_deck(
     deck_id: int,
-    decks_service: DecksService = fastapi.Depends(ioc.IOCContainer.decks_service),
+    decks_service: DecksService = FromDI(ioc.IOCContainer.decks_service),
 ) -> schemas.Deck:
     instance = await decks_service.get_one_or_none(
         models.Deck.id == deck_id,
@@ -45,7 +40,7 @@ async def get_deck(
 async def update_deck(
     deck_id: int,
     data: schemas.DeckCreate,
-    decks_service: DecksService = fastapi.Depends(ioc.IOCContainer.decks_service),
+    decks_service: DecksService = FromDI(ioc.IOCContainer.decks_service),
 ) -> schemas.Deck:
     try:
         instance = await decks_service.update(data=data.model_dump(), item_id=deck_id)
@@ -58,7 +53,7 @@ async def update_deck(
 @ROUTER.post("/decks/")
 async def create_deck(
     data: schemas.DeckCreate,
-    decks_service: DecksService = fastapi.Depends(ioc.IOCContainer.decks_service),
+    decks_service: DecksService = FromDI(ioc.IOCContainer.decks_service),
 ) -> schemas.Deck:
     instance = await decks_service.create(data)
     return typing.cast(schemas.Deck, instance)
@@ -67,7 +62,7 @@ async def create_deck(
 @ROUTER.get("/decks/{deck_id}/cards/")
 async def list_cards(
     deck_id: int,
-    cards_service: CardsService = fastapi.Depends(ioc.IOCContainer.cards_service),
+    cards_service: CardsService = FromDI(ioc.IOCContainer.cards_service),
 ) -> schemas.Cards:
     objects = await cards_service.list(models.Card.deck_id == deck_id)
     return typing.cast(schemas.Cards, {"items": objects})
@@ -76,7 +71,7 @@ async def list_cards(
 @ROUTER.get("/cards/{card_id}/")
 async def get_card(
     card_id: int,
-    cards_service: CardsService = fastapi.Depends(ioc.IOCContainer.cards_service),
+    cards_service: CardsService = FromDI(ioc.IOCContainer.cards_service),
 ) -> schemas.Card:
     instance = await cards_service.get_one_or_none(models.Card.id == card_id)
     if not instance:
@@ -88,7 +83,7 @@ async def get_card(
 async def create_cards(
     deck_id: int,
     data: list[schemas.CardCreate],
-    cards_service: CardsService = fastapi.Depends(ioc.IOCContainer.cards_service),
+    cards_service: CardsService = FromDI(ioc.IOCContainer.cards_service),
 ) -> schemas.Cards:
     objects = await cards_service.create_many(
         data=[models.Card(**card.model_dump(), deck_id=deck_id) for card in data],
@@ -100,7 +95,7 @@ async def create_cards(
 async def update_cards(
     deck_id: int,
     data: list[schemas.Card],
-    cards_service: CardsService = fastapi.Depends(ioc.IOCContainer.cards_service),
+    cards_service: CardsService = FromDI(ioc.IOCContainer.cards_service),
 ) -> schemas.Cards:
     objects = await cards_service.upsert_many(
         data=[models.Card(**card.model_dump(exclude={"deck_id"}), deck_id=deck_id) for card in data],

app/application.py

@@ -2,10 +2,13 @@
 import typing
 
 import fastapi
-from advanced_alchemy.exceptions import ForeignKeyError
+import modern_di
+import modern_di_fastapi
+from advanced_alchemy.exceptions import DuplicateKeyError, ForeignKeyError
 
 from app import exceptions, ioc
 from app.api.decks import ROUTER
+from app.settings import settings
 
 
 def include_routers(app: fastapi.FastAPI) -> None:
@@ -14,25 +17,29 @@ def include_routers(app: fastapi.FastAPI) -> None:
 
 class AppBuilder:
     def __init__(self) -> None:
-        self.settings = ioc.IOCContainer.settings.sync_resolve()
         self.app: fastapi.FastAPI = fastapi.FastAPI(
-            title=self.settings.service_name,
-            debug=self.settings.debug,
+            title=settings.service_name,
+            debug=settings.debug,
             lifespan=self.lifespan_manager,
+            dependencies=[fastapi.Depends(modern_di_fastapi.enter_di_request_scope)],
         )
+        self.di_container = modern_di.Container(scope=modern_di.Scope.APP)
+        modern_di_fastapi.save_di_container(self.app, self.di_container)
         include_routers(self.app)
         self.app.add_exception_handler(
             ForeignKeyError,
             exceptions.foreign_key_error_handler,  # type: ignore[arg-type]
         )
+        self.app.add_exception_handler(
+            DuplicateKeyError,
+            exceptions.foreign_key_error_handler,  # type: ignore[arg-type]
+        )
 
     @contextlib.asynccontextmanager
     async def lifespan_manager(self, _: fastapi.FastAPI) -> typing.AsyncIterator[dict[str, typing.Any]]:
-        try:
-            await ioc.IOCContainer.init_resources()
+        async with self.di_container:
+            await ioc.IOCContainer.async_resolve_creators(self.di_container)
             yield {}
-        finally:
-            await ioc.IOCContainer.tear_down()
 
 
 application = AppBuilder().app

app/exceptions.py

@@ -1,10 +1,10 @@
-from advanced_alchemy.exceptions import ForeignKeyError
+from advanced_alchemy.exceptions import DuplicateKeyError, ForeignKeyError
 from fastapi.responses import JSONResponse
 from starlette import status
 from starlette.requests import Request
 
 
-async def foreign_key_error_handler(_: Request, exc: ForeignKeyError) -> JSONResponse:
+async def foreign_key_error_handler(_: Request, exc: ForeignKeyError | DuplicateKeyError) -> JSONResponse:
     return JSONResponse(
         status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
         content={"detail": exc.detail},

app/ioc.py

@@ -1,15 +1,12 @@
-from that_depends import BaseContainer, providers
+from modern_di import BaseGraph, Scope, providers
 
 from app import repositories
 from app.resources.db import create_sa_engine, create_session
-from app.settings import Settings
 
 
-class IOCContainer(BaseContainer):
-    settings = providers.Singleton(Settings)
+class IOCContainer(BaseGraph):
+    database_engine = providers.Resource(Scope.APP, create_sa_engine)
+    session = providers.Resource(Scope.REQUEST, create_session, engine=database_engine.cast)
 
-    database_engine = providers.Resource(create_sa_engine, settings=settings.cast)
-    session = providers.ContextResource(create_session, engine=database_engine.cast)
-
-    decks_service = providers.Factory(repositories.DecksService, session=session)
-    cards_service = providers.Factory(repositories.CardsService, session=session)
+    decks_service = providers.Factory(Scope.REQUEST, repositories.DecksService, session=session.cast)
+    cards_service = providers.Factory(Scope.REQUEST, repositories.CardsService, session=session.cast)

app/resources/db.py

@@ -3,13 +3,13 @@
 
 from sqlalchemy.ext import asyncio as sa
 
-from app.settings import Settings
+from app.settings import settings
 
 
 logger = logging.getLogger(__name__)
 
 
-async def create_sa_engine(settings: Settings) -> typing.AsyncIterator[sa.AsyncEngine]:
+async def create_sa_engine() -> typing.AsyncIterator[sa.AsyncEngine]:
     logger.debug("Initializing SQLAlchemy engine")
     engine = sa.create_async_engine(
         url=settings.db_dsn,
@@ -27,6 +27,14 @@ async def create_sa_engine(settings: Settings) -> typing.AsyncIterator[sa.AsyncE
         logger.debug("SQLAlchemy engine has been cleaned up")
 
 
+class CustomAsyncSession(sa.AsyncSession):
+    async def close(self) -> None:
+        if isinstance(self.bind, sa.AsyncConnection):
+            return self.expunge_all()
+
+        return await super().close()
+
+
 async def create_session(engine: sa.AsyncEngine) -> typing.AsyncIterator[sa.AsyncSession]:
-    async with sa.AsyncSession(engine, expire_on_commit=False, autoflush=False) as session:
+    async with CustomAsyncSession(engine, expire_on_commit=False, autoflush=False) as session:
         yield session

app/settings.py

@@ -32,3 +32,6 @@ def db_dsn(self) -> URL:
             self.db_port,
             self.db_database,
         )
+
+
+settings = Settings()

migrations/env.py

@@ -3,12 +3,11 @@
 from alembic import context
 from sqlalchemy import URL, create_engine
 
-from app import ioc
 from app.models import METADATA
+from app.settings import settings
 
 
 def get_dsn() -> URL:
-    settings = ioc.IOCContainer.settings.sync_resolve()
     db_dsn = settings.db_dsn
     return db_dsn.set(drivername="postgresql")
 

pyproject.toml

@@ -14,16 +14,16 @@ dependencies = [
     "advanced-alchemy",
     "pydantic-settings",
     "granian",
-    "that-depends",
+    "modern-di-fastapi",
     # database
     "alembic",
     "psycopg2",
     "sqlalchemy",
     "asyncpg",
 ]
 
-[tool.uv]
-dev-dependencies = [
+[dependency-groups]
+dev = [
     "polyfactory",
     "httpx",
     "pytest",
@@ -38,7 +38,7 @@ dev-dependencies = [
 fix = true
 unsafe-fixes = true
 line-length = 120
-target-version = "py311"
+target-version = "py312"
 extend-exclude = ["bin"]
 
 [tool.ruff.lint]

tests/conftest.py

@@ -1,5 +1,7 @@
 import typing
 
+import modern_di
+import modern_di_fastapi
 import pytest
 from httpx import ASGITransport, AsyncClient
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -13,26 +15,27 @@ async def client() -> typing.AsyncIterator[AsyncClient]:
     async with AsyncClient(
         transport=ASGITransport(app=application),
         base_url="http://test",
-        timeout=0,
     ) as client:
         yield client
 
 
 @pytest.fixture(autouse=True)
-async def _prepare_ioc_container() -> typing.AsyncIterator[None]:
-    engine = await ioc.IOCContainer.database_engine()
-    connection = await engine.connect()
-    transaction = await connection.begin()
-    await connection.begin_nested()
-    session = AsyncSession(connection, expire_on_commit=False, autoflush=False)
-    ioc.IOCContainer.session.override(session)
-
-    try:
-        yield
-    finally:
-        if connection.in_transaction():
-            await transaction.rollback()
-        await connection.close()
-
-        ioc.IOCContainer.reset_override()
-        await ioc.IOCContainer.tear_down()
+async def di_container() -> modern_di.Container:
+    return modern_di_fastapi.fetch_di_container(application)
+
+
+@pytest.fixture(autouse=True)
+async def db_session(di_container: modern_di.Container) -> typing.AsyncIterator[AsyncSession]:
+    async with di_container:
+        engine = await ioc.IOCContainer.database_engine.async_resolve(di_container)
+        connection = await engine.connect()
+        transaction = await connection.begin()
+        await connection.begin_nested()
+        ioc.IOCContainer.database_engine.override(connection, di_container)
+
+        try:
+            yield AsyncSession(connection, expire_on_commit=False, autoflush=False)
+        finally:
+            if connection.in_transaction():
+                await transaction.rollback()
+            await connection.close()