Testing speedup with in memory SQLite (#189)

If no SQLite File is written and deleted testing is MUCH faster.

tests/conftest.py

@@ -1,12 +1,10 @@
 """Global configurations and definitions for pytest."""
 import datetime
-import os
 from collections.abc import Generator
 from inspect import getmembers, isfunction
 from typing import Any
 
 import pytest
-from sqlalchemy.engine import Engine
 from sqlalchemy.orm import Session, sessionmaker
 
 from aki_prj23_transparenzregister.config.config_template import SQLiteConnectionString
@@ -41,20 +39,12 @@ def _clear_caches() -> Generator[None, None, None]:
 @pytest.fixture()
 def empty_db() -> Generator[Session, None, None]:
     """Generates a db Session to a sql_lite db."""
-    if os.path.exists("test-db.db"):
-        os.remove("test-db.db")
-    db = sessionmaker(
-        autocommit=False,
-        autoflush=False,
-        bind=get_engine(SQLiteConnectionString("test-db.db")),
-    )()
+    engine = get_engine(SQLiteConnectionString(":memory:"))
+    db = sessionmaker(autocommit=False, autoflush=False, bind=engine)()
     init_db(db)
     yield db
     db.close()
-    bind = db.bind
-    assert isinstance(bind, Engine)
-    bind.dispose()
-    os.remove("test-db.db")
+    engine.dispose()
 
 
 @pytest.fixture()