feat(): format & proper startup (make main async for uvicorn to inherit current asyncio event loop)

src/template_project/migrations/env.py

@@ -1,3 +1,5 @@
+import asyncio
+import sys
 from logging.config import fileConfig
 import os
 from pathlib import Path
@@ -7,6 +9,9 @@ from sqlalchemy import pool
 
 from alembic import context
 
+if sys.platform == "win32":
+    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
+
 from template_project.web_api.configuration import load_configuration
 
 # this is the Alembic Config object, which provides
@@ -23,11 +28,13 @@ if config.config_file_name is not None:
 # from myapp import mymodel
 # target_metadata = mymodel.Base.metadata
 from template_project.adapters.data_gateways.tables import meta_data
+
 target_metadata = meta_data
 
 configuration = load_configuration(Path(os.environ["CONFIGURATION_PATH"]))
 config.set_main_option("sqlalchemy.url", configuration.database.url.get_value())
 
+
 # other values from the config, defined by the needs of env.py,
 # can be acquired:
 # my_important_option = config.get_main_option("my_important_option")

src/template_project/web_api/entry_point.py

@@ -1,6 +1,7 @@
 import argparse
 import asyncio
 import os
+import selectors
 import sys
 from collections.abc import AsyncIterator
 from contextlib import asynccontextmanager
@@ -70,27 +71,27 @@ def make_asgi_application(
     return app
 
 
-def _main(
+async def _main(
     configuration_path: Path,
 ) -> None:
     configuration = load_configuration(configuration_path)
     ioc = make_ioc(configuration)
     asgi_application = make_asgi_application(ioc)
 
-    uvicorn.run(
-        asgi_application,
-        port=configuration.server.port,
+    config = uvicorn.Config(
+        app=asgi_application,
         host=configuration.server.host,
+        port=configuration.server.port,
         log_config=LOG_CONFIG,
         access_log=configuration.server.access_log,
     )
+    server = uvicorn.Server(config)
+    await server.serve()
 
 
 def main() -> None:
     if sys.platform == "win32":
-        from asyncio import WindowsSelectorEventLoopPolicy  # noqa: PLC0415
-
-        asyncio.set_event_loop_policy(WindowsSelectorEventLoopPolicy())
+        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
 
     arg_parser = argparse.ArgumentParser()
     arg_parser.add_argument("configuration", default=None)
@@ -103,7 +104,7 @@ def main() -> None:
             "pass the path to the config or specify it in the environment variables `CONFIGURATION_PATH`",
         )
 
-    _main(Path(configuration_path))
+    asyncio.run(_main(Path(configuration_path)))
 
 
 if __name__ == "__main__":

src/template_project/web_api/routes/user.py

@@ -1,3 +1,5 @@
+import asyncio
+
 from dishka import FromDishka
 from dishka.integrations.fastapi import DishkaRoute
 from fastapi import APIRouter