2 files changed, 7 insertions, 2 deletions
diff --git a/BackEnd/Timeline/Services/UserDeleteService.cs b/BackEnd/Timeline/Services/UserDeleteService.cs
index b6306682..5365313b 100644
--- a/BackEnd/Timeline/Services/UserDeleteService.cs
+++ b/BackEnd/Timeline/Services/UserDeleteService.cs
@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using Timeline.Entities;
 using Timeline.Helpers;
 using Timeline.Models.Validation;
+using Timeline.Services.Exceptions;
 using static Timeline.Resources.Services.UserService;
 
 namespace Timeline.Services
@@ -20,6 +21,7 @@ namespace Timeline.Services
         /// <returns>True if user is deleted, false if user not exist.</returns>
         /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> is null.</exception>
         /// <exception cref="ArgumentException">Thrown when <paramref name="username"/> is of bad format.</exception>
+        /// <exception cref="InvalidOperationOnRootUserException">Thrown when deleting root user.</exception>
         Task<bool> DeleteUser(string username);
     }
 
@@ -54,6 +56,9 @@ namespace Timeline.Services
             if (user == null)
                 return false;
 
+            if (user.Id == 1)
+                throw new InvalidOperationOnRootUserException("Can't delete root user.");
+
             await _timelineService.DeleteAllPostsOfUser(user.Id);
 
             _databaseContext.Users.Remove(user);
diff --git a/BackEnd/Timeline/Services/UserPermissionService.cs b/BackEnd/Timeline/Services/UserPermissionService.cs
index 2fdf3d2d..42c93283 100644
--- a/BackEnd/Timeline/Services/UserPermissionService.cs
+++ b/BackEnd/Timeline/Services/UserPermissionService.cs
@@ -127,7 +127,7 @@ namespace Timeline.Services
         /// <param name="userId">The id of the user.</param>
         /// <param name="permission">The new permission.</param>
         /// <exception cref="UserNotExistException">Thrown when user does not exist.</exception>
-        /// <exception cref="InvalidOperationException">Thrown when change root user's permission.</exception>
+        /// <exception cref="InvalidOperationOnRootUserException">Thrown when change root user's permission.</exception>
         Task AddPermissionToUserAsync(long userId, UserPermission permission);
 
         /// <summary>
@@ -137,7 +137,7 @@ namespace Timeline.Services
         /// <param name="permission">The permission.</param>
         /// <param name="checkUserExistence">Whether check the user's existence.</param>
         /// <exception cref="UserNotExistException">Thrown when <paramref name="checkUserExistence"/> is true and user does not exist.</exception>
-        /// <exception cref="InvalidOperationException">Thrown when change root user's permission.</exception>
+        /// <exception cref="InvalidOperationOnRootUserException">Thrown when change root user's permission.</exception>
         Task RemovePermissionFromUserAsync(long userId, UserPermission permission, bool checkUserExistence = true);
     }