fix: allow lifespan to receive app=None (#30)

Author: hadrien

src/fastsqla.py

@@ -2,7 +2,7 @@
 import os
 from collections.abc import AsyncGenerator, Awaitable, Callable, Iterable
 from contextlib import _AsyncGeneratorContextManager, asynccontextmanager
-from typing import Annotated, Generic, TypeVar, TypedDict
+from typing import Annotated, Generic, TypedDict, TypeVar
 
 from fastapi import Depends as BaseDepends
 from fastapi import FastAPI, Query
@@ -90,7 +90,7 @@ class State(TypedDict):
 
 def new_lifespan(
     url: str | None = None, **kw
-) -> Callable[[FastAPI], _AsyncGeneratorContextManager[State, None]]:
+) -> Callable[[FastAPI | None], _AsyncGeneratorContextManager[State, None]]:
     """Create a new lifespan async context manager.
 
     It expects the exact same parameters as
@@ -117,7 +117,7 @@ def new_lifespan(
     has_config = url is not None
 
     @asynccontextmanager
-    async def lifespan(app: FastAPI) -> AsyncGenerator[State, None]:
+    async def lifespan(app: FastAPI | None) -> AsyncGenerator[State, None]:
         if has_config:
             prefix = ""
             sqla_config = {**kw, **{"url": url}}

tests/unit/test_lifespan.py

@@ -1,17 +1,23 @@
 from fastapi import FastAPI
-from pytest import raises
+from pytest import raises, fixture
 
-app = FastAPI()
+_app = FastAPI()
 
 
-async def test_it_returns_state(environ):
+@fixture(params=[_app, None])
+def app(request):
+    # lifespan tests pass whether lifespan receives app or None
+    return request.param
+
+
+async def test_it_returns_state(environ, app):
     from fastsqla import lifespan
 
     async with lifespan(app) as state:
         assert "fastsqla_engine" in state
 
 
-async def test_it_binds_an_sqla_engine_to_sessionmaker(environ):
+async def test_it_binds_an_sqla_engine_to_sessionmaker(environ, app):
     from fastsqla import SessionFactory, lifespan
 
     assert SessionFactory.kw["bind"] is None
@@ -24,7 +30,7 @@ async def test_it_binds_an_sqla_engine_to_sessionmaker(environ):
     assert SessionFactory.kw["bind"] is None
 
 
-async def test_it_fails_on_a_missing_sqlalchemy_url(monkeypatch):
+async def test_it_fails_on_a_missing_sqlalchemy_url(monkeypatch, app):
     from fastsqla import lifespan
 
     monkeypatch.delenv("SQLALCHEMY_URL", raising=False)
@@ -35,7 +41,7 @@ async def test_it_fails_on_a_missing_sqlalchemy_url(monkeypatch):
     assert raise_info.value.args[0] == "Missing sqlalchemy_url in environ."
 
 
-async def test_it_fails_on_not_async_engine(monkeypatch):
+async def test_it_fails_on_not_async_engine(monkeypatch, app):
     from fastsqla import lifespan
 
     monkeypatch.setenv("SQLALCHEMY_URL", "sqlite:///:memory:")
@@ -46,7 +52,7 @@ async def test_it_fails_on_not_async_engine(monkeypatch):
     assert "'pysqlite' is not async." in raise_info.value.args[0]
 
 
-async def test_new_lifespan_with_connect_args(sqlalchemy_url):
+async def test_new_lifespan_with_connect_args(sqlalchemy_url, app):
     from fastsqla import new_lifespan
 
     lifespan = new_lifespan(sqlalchemy_url, connect_args={"autocommit": False})
@@ -55,7 +61,7 @@ async def test_new_lifespan_with_connect_args(sqlalchemy_url):
         pass
 
 
-async def test_new_lifespan_fails_with_invalid_connect_args(sqlalchemy_url):
+async def test_new_lifespan_fails_with_invalid_connect_args(sqlalchemy_url, app):
     from fastsqla import new_lifespan
 
     lifespan = new_lifespan(sqlalchemy_url, connect_args={"this is wrong": False})