🪲 Always return empty JSON object on successful response, fixes #6160 (…

…#6161)

Fixes #6160, and potentially similar bugs as well. 

⚠️ I changes all occurrences of `'', 200` in `make_response`, but I only tested that `join_class` works as intended and #6160 is fixed. I don't know enough about the application to test the other occurrences effectively. This should be tested for the other functionality as well by a maintainer.

website/admin.py

@@ -166,7 +166,7 @@ def mark_as_teacher(self, username_teacher):
 
         update_is_teacher(self.db, teacher, is_teacher_value)
 
-        return make_response('', 200)
+        return make_response({}, 200)
 
     @route("/mark-super-teacher/<username_teacher>", methods=["POST"])
     @requires_admin
@@ -231,7 +231,7 @@ def change_user_email(self, user):
                 )
             except BaseException:
                 return make_response(gettext("mail_error_change_processed"), 400)
-        return make_response('', 200)
+        return make_response({}, 200)
 
     @route("/getUserTags", methods=["POST"])
     @requires_admin

website/auth_pages.py

@@ -487,7 +487,7 @@ def store_new_account(self, account, email):
                 )
             except BaseException:
                 return user, make_response({gettext("mail_error_change_processed")}, 400)
-            resp = make_response('', 200)
+            resp = make_response({}, 200)
         return user, resp
 
     @route('/public_profile', methods=['POST'])

website/classes.py

@@ -176,7 +176,7 @@ def join_class(self):
             # Also remove the pending message in this case
             session["messages"] = session["messages"] - 1 if session["messages"] else 0
 
-        return make_response('', 200)
+        return make_response({}, 200)
 
     @route("/<class_id>/student/<student_id>", methods=["DELETE"])
     @requires_login
@@ -187,7 +187,7 @@ def leave_class(self, user, class_id, student_id):
 
         self.db.remove_student_from_class(Class["id"], student_id)
         refresh_current_user_from_db()
-        return make_response('', 200)
+        return make_response({}, 200)
 
     @route("/<class_id>/second-teacher/<second_teacher>", methods=["DELETE"])
     @requires_login
@@ -199,7 +199,7 @@ def remove_second_teacher(self, user, class_id, second_teacher):
         self.db.remove_second_teacher_from_class(Class, second_teacher)
 
         refresh_current_user_from_db()
-        return make_response('', 200)
+        return make_response({}, 200)
 
 
 class MiscClassPages(WebsiteModule):

website/tags.py

@@ -120,4 +120,4 @@ def delete_tag(self, user, tag):
         for adventure in db_tag['tagged_in']:
             self.db.delete_tag_from_adventure(tag, adventure['id'])
 
-        return make_response('', 200)
+        return make_response({}, 200)