validor more explicit

fractal_server/app/models/security.py

@@ -110,7 +110,7 @@ class UserOAuth(SQLModel, table=True):
         foreign_key="user_settings.id", default=None
     )
     settings: Optional[UserSettings] = Relationship(
-        sa_relationship_kwargs=dict(lazy="selectin")
+        sa_relationship_kwargs=dict(lazy="selectin", cascade="all, delete")
     )
 
     class Config:

tests/no_version/test_delete_user.py

@@ -2,6 +2,7 @@
 from sqlmodel import select
 
 from fractal_server.app.models.security import UserOAuth
+from fractal_server.app.models.security import UserSettings
 from fractal_server.app.models.v1 import LinkUserProject
 from fractal_server.app.models.v2 import LinkUserProjectV2
 
@@ -54,3 +55,33 @@ async def test_delete_user(
     assert len(project_v2.user_list) == 0
     assert len(project_v1_2.user_list) == 1
     assert len(project_v2_2.user_list) == 1
+
+
+async def test_cascade_on_delete_user_settings(db):
+
+    user = UserOAuth(
+        email="user@fractal.xy",
+        hashed_password="fake_hashed_password",
+        settings=UserSettings(slurm_accounts=["account1", "account2"]),
+    )
+    db.add(user)
+    await db.commit()
+
+    await db.refresh(user)
+    user_id = user.id
+    user_settings_id = user.user_settings_id
+
+    await db.close()
+
+    user = await db.get(UserOAuth, user_id)
+    assert user is not None
+    user_settings = await db.get(UserSettings, user_settings_id)
+    assert user_settings is not None
+
+    await db.delete(user)
+    await db.commit()
+
+    user = await db.get(UserOAuth, user_id)
+    assert user is None
+    user_settings = await db.get(UserSettings, user_settings_id)
+    assert user_settings is None