From 83277af66f68379fcd7b6bfb5d00a504dcb46f6a Mon Sep 17 00:00:00 2001
From: Dave Roman <43916038+MrDave1999@users.noreply.github.com>
Date: Tue, 18 Apr 2023 13:01:22 -0500
Subject: [PATCH] Added support for handle database errors  (#184)

* Added `EntityFramework.Exceptions` package

* Changed the type of the `ResponseBase.Errors` property to `IEnumerable<string>`

* Error has been handled when the unique restriction is violated
---
 src/Constants/ResponseMessages.cs              | 2 ++
 src/DataAccess/AppDbContext.cs                 | 1 +
 src/DentallApp.csproj                          | 1 +
 src/Extensions/MvcBuilderExtensions.cs         | 4 ++--
 src/GlobalUsings.cs                            | 2 ++
 src/Middlewares/ExceptionHandlingMiddleware.cs | 6 ++++++
 src/Responses/ResponseBase.cs                  | 2 +-
 7 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/Constants/ResponseMessages.cs b/src/Constants/ResponseMessages.cs
index 1593336b..6d386ef2 100644
--- a/src/Constants/ResponseMessages.cs
+++ b/src/Constants/ResponseMessages.cs
@@ -11,6 +11,8 @@ public class ResponseMessages
 
     public const string UnexpectedErrorMessage                             = "Hubo un error inesperado, por favor intente de nuevo.";
     public const string UnexpectedErrorsMessage                            = "Se encontraron errores inesperados, por favor intente de nuevo.";
+    public const string UniqueConstraintViolatedMessage                    = "Se detectó una violación a una restricción única (UNIQUE INDEX). " +
+                                                                             "Por favor, no envíe una entrada duplicada.";
 
     public const string DirectLineTokenFailedMessage                       = "Direct Line token API call failed.";
     public const string InactiveUserAccountMessage                         = "Cuenta de usuario inactiva.";
diff --git a/src/DataAccess/AppDbContext.cs b/src/DataAccess/AppDbContext.cs
index a15fa731..008ae7f7 100644
--- a/src/DataAccess/AppDbContext.cs
+++ b/src/DataAccess/AppDbContext.cs
@@ -12,6 +12,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
                 // See https://github.com/DentallApp/back-end/issues/25.
                 warnings.Ignore(CoreEventId.PossibleIncorrectRequiredNavigationWithQueryFilterInteractionWarning));
         optionsBuilder.AddDelegateDecompiler();
+        optionsBuilder.UseExceptionProcessor();
     }
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
diff --git a/src/DentallApp.csproj b/src/DentallApp.csproj
index 487e9c97..5562ced0 100755
--- a/src/DentallApp.csproj
+++ b/src/DentallApp.csproj
@@ -16,6 +16,7 @@
     <PackageReference Include="EFCore.CustomDbContext" Version="1.0.0" />
     <PackageReference Include="EFCore.CustomQueryPreprocessor" Version="2.0.0" />
     <PackageReference Include="EFCore.NamingConventions" Version="7.0.0" />
+    <PackageReference Include="EntityFrameworkCore.Exceptions.MySQL.Pomelo" Version="6.0.3" />
     <PackageReference Include="File.TypeChecker" Version="3.0.0" />
     <PackageReference Include="itext7.pdfhtml" Version="4.0.5" />
     <PackageReference Include="libphonenumber-csharp" Version="8.13.4" />
diff --git a/src/Extensions/MvcBuilderExtensions.cs b/src/Extensions/MvcBuilderExtensions.cs
index ba0f97d2..89f9f8ad 100644
--- a/src/Extensions/MvcBuilderExtensions.cs
+++ b/src/Extensions/MvcBuilderExtensions.cs
@@ -16,11 +16,11 @@ where state.Value.Errors.Count > 0
                                   ErrorMessages = state.Value.Errors.Select(modelError => modelError.ErrorMessage)
                               }).ToDictionary(x => x.Key, x => x.ErrorMessages);
 
-                var result = new Response
+                var result = new
                 {
                     Success = false,
                     Message = InvalidModelStateMessage,
-                    Errors = errors
+                    Errors  = errors
                 };
                 return new BadRequestObjectResult(result);
             };
diff --git a/src/GlobalUsings.cs b/src/GlobalUsings.cs
index 443051bf..75b36edd 100644
--- a/src/GlobalUsings.cs
+++ b/src/GlobalUsings.cs
@@ -143,6 +143,8 @@
 global using SendGrid.Helpers.Mail;
 global using SendGrid.Extensions.DependencyInjection;
 
+global using EntityFramework.Exceptions.Common;
+global using EntityFramework.Exceptions.MySQL.Pomelo;
 global using DelegateDecompiler;
 global using FileTypeChecker;
 global using FileTypeChecker.Extensions;
diff --git a/src/Middlewares/ExceptionHandlingMiddleware.cs b/src/Middlewares/ExceptionHandlingMiddleware.cs
index 1674dcfe..b7dc065b 100644
--- a/src/Middlewares/ExceptionHandlingMiddleware.cs
+++ b/src/Middlewares/ExceptionHandlingMiddleware.cs
@@ -34,6 +34,12 @@ public async Task InvokeAsync(HttpContext context)
                 Message = UnexpectedErrorMessage
             };
 
+            if (exception is UniqueConstraintException)
+            {
+                context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
+                response.Errors = new[] { UniqueConstraintViolatedMessage };
+            }
+
             await context.Response.WriteAsJsonAsync(response);
         }
     }
diff --git a/src/Responses/ResponseBase.cs b/src/Responses/ResponseBase.cs
index 3aa328d7..ce830004 100644
--- a/src/Responses/ResponseBase.cs
+++ b/src/Responses/ResponseBase.cs
@@ -4,7 +4,7 @@ public class ResponseBase
 {
     public bool Success { get; set; }
     public string Message { get; set; }
-    public IDictionary<string, IEnumerable<string>> Errors { get; set; }
+    public IEnumerable<string> Errors { get; set; }
 
     public ResponseBase()
     {