From 9cffe73b9788701365d9781c67549bdc16597ff4 Mon Sep 17 00:00:00 2001
From: Aliyan Ali <darkpikayt1@gmail.com>
Date: Sat, 4 Jan 2025 16:20:54 +0500
Subject: [PATCH 1/2]  add Validations

---
 app/models/course.rb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/models/course.rb b/app/models/course.rb
index 02e50ddfe4..9b2912fde5 100644
--- a/app/models/course.rb
+++ b/app/models/course.rb
@@ -60,6 +60,9 @@ class Course < ApplicationRecord
   ######################
   # Users for a course #
   ######################
+  # Validations
+  validates :slug, presence: true, uniqueness: { message: "Slug must be unique. Another course with this slug already exists." }
+
   has_many :courses_users, class_name: 'CoursesUsers', dependent: :destroy
   has_many :users, -> { distinct }, through: :courses_users
   has_many :students, -> { where('courses_users.role = 0') },

From d8f1fed3899f3175b09c1ae0760a27131d655bce Mon Sep 17 00:00:00 2001
From: Aliyan Ali <darkpikayt1@gmail.com>
Date: Sat, 4 Jan 2025 16:22:31 +0500
Subject: [PATCH 2/2] Update the def update  to handle errors gracefully

---
 app/controllers/courses_controller.rb | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 49cbcf7ad5..469d21b11f 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -44,18 +44,25 @@ def update
     validate
     handle_course_announcement(@course.instructors.first)
     slug_from_params if should_set_slug?
-    @course.update update_params
-    update_courses_wikis
-    update_course_wiki_namespaces
-    update_flags
-    ensure_passcode_set
-    UpdateCourseWorker.schedule_edits(course: @course, editing_user: current_user)
-    render json: { course: @course }
+  
+    if @course.update(update_params)
+      update_courses_wikis
+      update_course_wiki_namespaces
+      update_flags
+      ensure_passcode_set
+      UpdateCourseWorker.schedule_edits(course: @course, editing_user: current_user)
+      render json: { course: @course }
+    else
+      # If update fails, check for validation errors (e.g., duplicate slug)
+      render json: { errors: @course.errors.full_messages },
+             status: :unprocessable_entity
+    end
   rescue Wiki::InvalidWikiError => e
     message = I18n.t('courses.error.invalid_wiki', domain: e.domain)
     render json: { errors: e, message: },
            status: :not_found
   end
+  
 
   def destroy
     validate