fix: make otl link invalid if user was purged

ckanext/let_me_in/tests/test_views.py

@@ -33,3 +33,12 @@ def test_user_login_expires_the_otl(self, app, user):
             "You have tried to use a one-time login link that has expired"
             in app.get(otl["url"]).body
         )
+
+    def test_visit_link_after_user_has_been_deleted(self, app, user):
+        otl = call_action("lmi_generate_otl", uid=user["id"])
+
+        user = cast(model.User, model.User.get(user["id"]))
+        user.purge()
+        user.commit()
+
+        assert "Invalid login link" in app.get(otl["url"]).body

ckanext/let_me_in/utils.py

@@ -15,9 +15,9 @@ def get_secret(encode: bool) -> str:
     return _get_secret(encode)
 
 
-def get_user(user_id: str) -> model.User:
+def get_user(user_id: str) -> model.User | None:
     """Get a user by its ID/name"""
-    return cast(model.User, model.User.get(user_id))
+    return model.User.get(user_id)
 
 
 def update_user_last_active(user: model.User) -> None:

ckanext/let_me_in/views.py

@@ -27,6 +27,11 @@ def login_with_token(token):
         tk.h.flash_error(tk._("Invalid login link."))
     else:
         user = lmi_utils.get_user(token["user_id"])
+
+        if not user:
+            tk.h.flash_error(tk._("Invalid login link."))
+            return tk.h.redirect_to("user.login")
+
         context = {}
 
         for plugin in p.PluginImplementations(ILetMeIn):