Correcting registration bug

src/CraftSharp/Pages/Inscription.razor.cs

@@ -36,14 +36,21 @@ namespace CraftSharp.Pages
 
         private async Task OnSubmit()
         {
-
-            await AuthStateProvider.Register(registerRequest);
-            var stringified = JsonConvert.SerializeObject(new ConnexionModel() { 
-                Password=registerRequest.Password, 
-                UserName=registerRequest.UserName}
-            );
-            var response = await httpClient.PostAsJsonAsync($"{NavigationManager.BaseUri}User/SetUser", stringified);
-            NavigationManager.NavigateTo("index");
+            try
+            {
+                await AuthStateProvider.Register(registerRequest);
+                var stringified = JsonConvert.SerializeObject(new ConnexionModel()
+                {
+                    Password = registerRequest.Password,
+                    UserName = registerRequest.UserName
+                }
+                );
+                var response = await httpClient.PostAsJsonAsync($"{NavigationManager.BaseUri}User/SetUser", stringified);
+                NavigationManager.NavigateTo("index");
+            }catch (Exception ex)
+            {
+                error = ex.Message;
+            }
 
         }
     }

src/CraftSharp/Services/AuthService.cs

@@ -65,7 +65,17 @@ namespace CraftSharp.Services
 
         public void Register(InscriptionModel registerRequest)
         {
-            CurrentUser.Add(new AppUser { UserName = registerRequest.UserName, Password = registerRequest.Password, Roles = new List<UserRoles> { UserRoles.User } });
+            var user = CurrentUser.FirstOrDefault(w => w.UserName == registerRequest.UserName);
+
+            if (user == null)
+            {
+                CurrentUser.Add(new AppUser { UserName = registerRequest.UserName, Password = registerRequest.Password, Roles = new List<UserRoles> { UserRoles.User } });
+            }
+            else
+            {
+                throw new Exception("Username already taken !");
+
+            }
         }
     }
 }