refactor: extract open_db() context manager from lifespan

src/porchlight/app.py

@@ -4,7 +4,6 @@ from contextlib import asynccontextmanager
 from pathlib import Path
 from urllib.parse import urlparse
 
-import aiosqlite
 from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 from fastapi.templating import Jinja2Templates
@@ -18,7 +17,7 @@ from porchlight.invite.service import MagicLinkService
 from porchlight.manage.routes import router as manage_router
 from porchlight.oidc.endpoints import router as oidc_router
 from porchlight.oidc.provider import create_oidc_server
-from porchlight.store.sqlite.migrations import run_migrations
+from porchlight.store.sqlite.db import open_db
 from porchlight.store.sqlite.repositories import (
     SQLiteCredentialRepository,
     SQLiteMagicLinkRepository,
@@ -33,13 +32,7 @@ MIGRATIONS_DIR = PACKAGE_DIR / "store" / "sqlite" / "migrations"
 async def lifespan(app: FastAPI) -> AsyncIterator[None]:
     settings: Settings = app.state.settings
     if settings.storage_backend == StorageBackend.SQLITE:
-        if settings.sqlite_path != ":memory:":
-            Path(settings.sqlite_path).parent.mkdir(parents=True, exist_ok=True)
-        db = await aiosqlite.connect(settings.sqlite_path)
-        db.row_factory = aiosqlite.Row
-        await db.execute("PRAGMA journal_mode=WAL")
-        await db.execute("PRAGMA foreign_keys=ON")
-        await run_migrations(db, MIGRATIONS_DIR)
+        async with open_db(settings.sqlite_path, MIGRATIONS_DIR) as db:
             app.state.user_repo = SQLiteUserRepository(db)
             app.state.credential_repo = SQLiteCredentialRepository(db)
             app.state.magic_link_repo = SQLiteMagicLinkRepository(db)
@@ -78,7 +71,6 @@ async def lifespan(app: FastAPI) -> AsyncIterator[None]:
             oidc_server.keyjar.add_symmetric(settings.manage_client_id, manage_secret)
 
             yield
-        await db.close()
     else:
         raise NotImplementedError("MongoDB backend not yet implemented")
 

src/porchlight/store/sqlite/db.py

@@ -0,0 +1,23 @@
+from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
+from pathlib import Path
+
+import aiosqlite
+
+from porchlight.store.sqlite.migrations import run_migrations
+
+
+@asynccontextmanager
+async def open_db(db_path: str, migrations_dir: Path) -> AsyncIterator[aiosqlite.Connection]:
+    """Open a SQLite connection with WAL mode, foreign keys, and migrations applied."""
+    if db_path != ":memory:":
+        Path(db_path).parent.mkdir(parents=True, exist_ok=True)
+    db = await aiosqlite.connect(db_path)
+    try:
+        db.row_factory = aiosqlite.Row
+        await db.execute("PRAGMA journal_mode=WAL")
+        await db.execute("PRAGMA foreign_keys=ON")
+        await run_migrations(db, migrations_dir)
+        yield db
+    finally:
+        await db.close()

tests/test_store/test_db.py

@@ -0,0 +1,45 @@
+from pathlib import Path
+
+import aiosqlite
+import pytest
+
+from porchlight.store.sqlite.db import open_db
+
+MIGRATIONS_DIR = (
+    Path(__file__).resolve().parent.parent.parent / "src" / "porchlight" / "store" / "sqlite" / "migrations"
+)
+
+
+@pytest.fixture
+def migrations_dir() -> Path:
+    return MIGRATIONS_DIR
+
+
+async def test_open_db_returns_connection(tmp_path: Path, migrations_dir: Path) -> None:
+    db_path = str(tmp_path / "test.db")
+    async with open_db(db_path, migrations_dir) as db:
+        assert isinstance(db, aiosqlite.Connection)
+
+
+async def test_open_db_runs_migrations(tmp_path: Path, migrations_dir: Path) -> None:
+    db_path = str(tmp_path / "test.db")
+    async with (
+        open_db(db_path, migrations_dir) as db,
+        db.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='users'") as cursor,
+    ):
+        row = await cursor.fetchone()
+        assert row is not None
+
+
+async def test_open_db_sets_wal_mode(tmp_path: Path, migrations_dir: Path) -> None:
+    db_path = str(tmp_path / "test.db")
+    async with open_db(db_path, migrations_dir) as db, db.execute("PRAGMA journal_mode") as cursor:
+        row = await cursor.fetchone()
+        assert row[0] == "wal"
+
+
+async def test_open_db_creates_parent_dirs(tmp_path: Path, migrations_dir: Path) -> None:
+    db_path = str(tmp_path / "sub" / "dir" / "test.db")
+    async with open_db(db_path, migrations_dir) as db:
+        assert isinstance(db, aiosqlite.Connection)
+    assert (tmp_path / "sub" / "dir" / "test.db").exists()