🧹 When returning an empty succes, use 204 instead of 200 (#5455)

Fixes a part of #4029 

**How to test**
1. All unittests should pass
2. Check if all new returns are correct

app.py

@@ -21,7 +21,7 @@
 
 import static_babel_content
 from markupsafe import Markup
-from flask import (Flask, Response, abort, after_this_request, g,
+from flask import (Flask, Response, abort, after_this_request, g, make_response,
                    redirect, request, send_file, url_for, jsonify,
                    send_from_directory, session)
 from flask_babel import Babel, gettext
@@ -716,7 +716,7 @@ def parse_by_id(user):
                 program.get('level'),
                 program.get('lang')
             )
-            return {}, 200
+            return make_response('', 204)
         except BaseException:
             return {"error": "parsing error"}, 200
     else:
@@ -2265,7 +2265,7 @@ def change_language():
     # Remove 'keyword_lang' from session, it will automatically be renegotiated from 'lang'
     # on the next page load.
     session.pop('keyword_lang')
-    return jsonify({'succes': 200})
+    return jsonify({'success': 204})
 
 
 @app.route('/slides', methods=['GET'], defaults={'level': '1'})
@@ -2347,7 +2347,7 @@ def store_parsons_order():
     }
 
     DATABASE.store_parsons(attempt)
-    return jsonify({}), 200
+    return make_response('', 204)
 
 
 @app.template_global()

static/js/app.ts

@@ -1622,7 +1622,7 @@ export function toggle_blur_code() {
 export async function change_language(lang: string) {
   await tryCatchPopup(async () => {
     const response = await postJsonWithAchievements('/change_language', { lang });
-    if (response.succes) {
+    if (response.success) {
       const queryString = window.location.search;
       const urlParams = new URLSearchParams(queryString);
 

static/js/appbundle.js

@@ -100052,7 +100052,7 @@ def note_with_error(value, err):
   async function change_language(lang) {
     await tryCatchPopup(async () => {
       const response = await postJsonWithAchievements("/change_language", { lang });
-      if (response.succes) {
+      if (response.success) {
         const queryString = window.location.search;
         const urlParams = new URLSearchParams(queryString);
         if (lang === "en" || urlParams.get("language") !== null) {

tests_e2e.py

@@ -232,7 +232,7 @@ def get_data(self, path, expect_http_code=200, no_cookie=False, return_headers=F
 
     def destroy_current_user(self):
         assert self.username is not None
-        self.post_data('auth/destroy', '')
+        self.post_data('auth/destroy', '', 204)
         # Remove any records of this user
         USERS.pop(self.username)
 
@@ -585,7 +585,7 @@ def test_logout(self):
 
         # WHEN logging out the user
         # THEN receive an OK response code from the server
-        self.post_data('auth/logout', '')
+        self.post_data('auth/logout', '', 204)
 
         # WHEN retrieving the user profile with the same cookie
         # THEN first receive a redirect response code from the server, and the next
@@ -965,7 +965,7 @@ def test_destroy_public_profile(self):
 
         # WHEN destroying the public profile
         # THEN receive an OK response from the server
-        self.post_data('auth/destroy_public', public_profile, expect_http_code=200)
+        self.post_data('auth/destroy_public', public_profile, expect_http_code=204)
 
 
 class TestProgram(AuthHelper):

website/achievements.py

@@ -1,4 +1,4 @@
-from flask import jsonify, request, session
+from flask import jsonify, make_response, request, session
 from flask_babel import gettext
 
 import hedy
@@ -280,4 +280,4 @@ def push_new_achievement(self, user):
                         )
                     }
                 )
-        return jsonify({})
+        return make_response('', 204)

website/admin.py

@@ -1,4 +1,4 @@
-from flask import request
+from flask import make_response, request
 from flask_babel import gettext
 
 import hedyweb
@@ -237,7 +237,7 @@ def change_user_email(self, user):
             except BaseException:
                 return gettext("mail_error_change_processed"), 400
 
-        return {}, 200
+        return make_response('', 204)
 
     @route("/getUserTags", methods=["POST"])
     @requires_admin
@@ -273,7 +273,7 @@ def update_user_tags(self, user):
         db_user["tags"] = tags
 
         self.db.update_public_profile(username, db_user)
-        return {}, 200
+        return make_response('', 204)
 
 
 def update_is_teacher(db: Database, user, is_teacher_value=1):

website/auth_pages.py

@@ -248,7 +248,7 @@ def logout(self):
             self.db.forget_token(request.cookies.get(TOKEN_COOKIE_NAME))
         session[JUST_LOGGED_OUT] = True
         remove_class_preview()
-        return "", 200
+        return make_response('', 204)
 
     @ route("/destroy", methods=["POST"])
     @ requires_login
@@ -257,14 +257,14 @@ def destroy(self, user):
         self.db.forget_token(request.cookies.get(TOKEN_COOKIE_NAME))
         self.db.forget_user(user["username"])
         session[JUST_LOGGED_OUT] = True
-        return "", 200
+        return make_response('', 204)
 
     @ route("/destroy_public", methods=["POST"])
     @ requires_login
     def destroy_public(self, user):
         self.db.forget_public_profile(user["username"])
         session.pop("profile_image", None)  # Delete profile image id if existing
-        return "", 200
+        return make_response('', 204)
 
     @ route("/change_student_password", methods=["POST"])
     @ requires_login

website/classes.py

@@ -1,6 +1,6 @@
 import uuid
 
-from flask import jsonify, redirect, request, session
+from flask import jsonify, make_response, redirect, request, session
 from jinja_partials import render_partial
 from flask_babel import gettext
 
@@ -88,7 +88,7 @@ def update_class(self, user, class_id):
         achievement = self.achievements.add_single_achievement(user["username"], "on_second_thoughts")
         if achievement:
             return {"achievement": achievement}, 200
-        return {}, 200
+        return make_response('', 204)
 
     @route("/<class_id>", methods=["DELETE"])
     @requires_login
@@ -200,7 +200,7 @@ def join_class(self):
         if achievement:
             return {"achievement": achievement}, 200
         else:
-            return {}, 200
+            return make_response('', 204)
 
     @route("/<class_id>/student/<student_id>", methods=["DELETE"])
     @requires_login
@@ -216,7 +216,7 @@ def leave_class(self, user, class_id, student_id):
             achievement = self.achievements.add_single_achievement(user["username"], "detention")
         if achievement:
             return {"achievement": achievement}, 200
-        return {}, 200
+        return make_response('', 204)
 
     @route("/<class_id>/second-teacher/<second_teacher>", methods=["DELETE"])
     @requires_login
@@ -357,7 +357,7 @@ def invite_student(self, user):
             "invited_as_text": gettext("student"),
         }
         self.db.add_class_invite(data)
-        return {}, 200
+        return make_response('', 204)
 
     @route("/invite-second-teacher", methods=["POST"])
     @requires_teacher
@@ -404,7 +404,7 @@ def invite_second_teaceher(self, user):
             "invited_as_text": gettext("second_teacher"),
         }
         self.db.add_class_invite(data)
-        return {}, 200
+        return make_response('', 204)
 
     @route("/remove_student_invite", methods=["POST"])
     @requires_login
@@ -429,7 +429,7 @@ def remove_invite(self, user):
             return utils.error_page(error=404, ui_message=gettext("no_such_class"))
 
         self.db.remove_user_class_invite(username, class_id)
-        return {}, 200
+        return make_response('', 204)
 
     @route("/hedy/l/<link_id>", methods=["GET"])
     def resolve_class_link(self, link_id):

website/statistics.py

@@ -2,7 +2,7 @@
 from enum import Enum
 from difflib import SequenceMatcher
 import re
-from flask import g, jsonify, request
+from flask import g, jsonify, make_response, request
 from flask_babel import gettext
 import utils
 import hedy_content
@@ -820,7 +820,7 @@ def remove_common_error_item(self, user, class_id, error_id):
                 self.db.update_class_errors(common_errors)
                 break
 
-        return {}, 200
+        return make_response('', 204)
 
     def retrieve_exceptions_per_student(self, class_id):
         """
@@ -954,7 +954,7 @@ def select_levels(self, user, class_id):
 
         self.db.update_class_customizations(class_customization)
 
-        return {}, 200
+        return make_response('', 204)
 
 
 def add(username, action):

website/tags.py

@@ -1,4 +1,4 @@
-from flask import request, g
+from flask import make_response, request, g
 from flask_babel import gettext
 import jinja_partials
 import uuid
@@ -89,7 +89,8 @@ def delete_from_adventure(self, user, tag, adventure_id):
         # This only deletes a tag from an adventure.
         # TODO: perhaps allow admin to permanently delete a tag.
         if not tag or not adventure_id:
-            return {}, 200
+            # is this not suppossed to be an error response?
+            return make_response('', 204)
 
         tag_name = tag.strip()
         db_tag = self.db.read_tag(tag_name)

website/user_activity.py

@@ -1,6 +1,6 @@
 
 import os
-from flask import request, session
+from flask import make_response, request, session
 
 # import utils
 from config import config
@@ -62,6 +62,6 @@ def index(self, user):
 
         try:
             logger.log(data)
-            return {}, 200
+            return make_response('', 204)
         except IOError:
             return "Not logged", 400