Migrate application and API to use ErrorOr for error handling

src/Voltiq.API/Controllers/Auth/AuthController.cs

@@ -25,7 +25,7 @@ public async Task<IActionResult> Login(
         var command = request.ToCommand();
         var result = await Sender.Send(command, cancellationToken);
 
-        return result.IsFailure ? ToErrorResult(result) : Ok(result.Value);
+        return result.IsError ? ToErrorResult(result) : Ok(result.Value);
     }
 
     /// <summary>Exchanges a valid refresh token for a new access token and refresh token (rotation).</summary>
@@ -43,7 +43,7 @@ public async Task<IActionResult> Refresh(
     {
         var result = await Sender.Send(request.ToCommand(), cancellationToken);
 
-        return result.IsFailure ? ToErrorResult(result) : Ok(result.Value);
+        return result.IsError ? ToErrorResult(result) : Ok(result.Value);
     }
 
     /// <summary>Returns the currently authenticated user.</summary>
@@ -58,6 +58,6 @@ public async Task<IActionResult> Me(CancellationToken cancellationToken)
     {
         var result = await Sender.Send(new GetCurrentUserQuery(), cancellationToken);
 
-        return result.IsFailure ? ToErrorResult(result) : Ok(result.Value);
+        return result.IsError ? ToErrorResult(result) : Ok(result.Value);
     }
 }

src/Voltiq.API/Controllers/BaseApiController.cs

@@ -1,8 +1,7 @@
 using System.Diagnostics.CodeAnalysis;
+using ErrorOr;
 using MediatR;
 using Microsoft.AspNetCore.Mvc;
-using Voltiq.Domain.Common;
-using Voltiq.Exceptions.Errors;
 using Voltiq.Exceptions.Resources;
 
 namespace Voltiq.API.Controllers;
@@ -15,29 +14,29 @@ public abstract class BaseApiController : ControllerBase
     protected ISender Sender =>
         field ??= HttpContext.RequestServices.GetRequiredService<ISender>();
 
-    protected IActionResult ToErrorResult(Result result)
+    protected IActionResult ToErrorResult<T>(ErrorOr<T> result)
     {
         var firstError = result.FirstError;
 
-        return firstError switch
+        return firstError.Type switch
         {
-            ValidationError => ValidationProblem(firstError, result),
+            ErrorType.Validation => BuildValidationProblem(result.Errors),
 
-            NotFoundError notFound => Problem(
+            ErrorType.NotFound => Problem(
                 title: ResourceErrorMessages.TITULO_NAO_ENCONTRADO,
-                detail: notFound.Message,
+                detail: firstError.Description,
                 statusCode: StatusCodes.Status404NotFound,
                 instance: HttpContext.Request.Path),
 
-            ConflictError conflict => Problem(
+            ErrorType.Conflict => Problem(
                 title: ResourceErrorMessages.TITULO_CONFLITO,
-                detail: conflict.Message,
+                detail: firstError.Description,
                 statusCode: StatusCodes.Status409Conflict,
                 instance: HttpContext.Request.Path),
 
-            UnauthorizedError unauthorized => Problem(
+            ErrorType.Unauthorized => Problem(
                 title: ResourceErrorMessages.TITULO_NAO_AUTORIZADO,
-                detail: unauthorized.Message,
+                detail: firstError.Description,
                 statusCode: StatusCodes.Status401Unauthorized,
                 instance: HttpContext.Request.Path),
 
@@ -48,19 +47,19 @@ protected IActionResult ToErrorResult(Result result)
         };
     }
 
-    private ObjectResult ValidationProblem(Error _, Result result)
+    private ObjectResult BuildValidationProblem(List<Error> errors)
     {
-        var errors = new Dictionary<string, string[]>();
+        var dict = new Dictionary<string, string[]>();
 
-        foreach (var error in result.Errors.OfType<ValidationError>())
+        foreach (var error in errors.Where(e => e.Type == ErrorType.Validation))
         {
-            if (!errors.ContainsKey(error.PropertyName))
-                errors[error.PropertyName] = [];
+            if (!dict.ContainsKey(error.Code))
+                dict[error.Code] = [];
 
-            errors[error.PropertyName] = [.. errors[error.PropertyName], error.Message];
+            dict[error.Code] = [.. dict[error.Code], error.Description];
         }
 
-        var problemDetails = new ValidationProblemDetails(errors)
+        var problemDetails = new ValidationProblemDetails(dict)
         {
             Title = ResourceErrorMessages.TITULO_FALHA_VALIDACAO,
             Status = StatusCodes.Status400BadRequest,

src/Voltiq.API/Controllers/Users/UsersController.cs

@@ -23,7 +23,7 @@ public async Task<IActionResult> Create(
         var command = request.ToCommand();
         var result = await Sender.Send(command, cancellationToken);
 
-        return result.IsFailure ?
+        return result.IsError ?
             ToErrorResult(result) :
             CreatedAtAction(nameof(Create), new { id = result.Value.Id }, result.Value);
     }

src/Voltiq.API/Voltiq.API.csproj

@@ -7,6 +7,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="ErrorOr" Version="2.0.1" />
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="10.0.4" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.3">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/Voltiq.Application/Common/Behaviors/ValidationBehavior.cs

@@ -1,14 +1,14 @@
+using System.Reflection;
+using ErrorOr;
 using FluentValidation;
 using MediatR;
-using Voltiq.Domain.Common;
-using Voltiq.Exceptions.Errors;
 
 namespace Voltiq.Application.Common.Behaviors;
 
 public sealed class ValidationBehavior<TRequest, TResponse>(IEnumerable<IValidator<TRequest>> validators)
     : IPipelineBehavior<TRequest, TResponse>
     where TRequest : IRequest<TResponse>
-    where TResponse : Result
+    where TResponse : IErrorOr
 {
     public async Task<TResponse> Handle(
         TRequest request,
@@ -30,7 +30,7 @@ public async Task<TResponse> Handle(
             return await next(cancellationToken);
 
         var errors = failures
-            .Select(Error (f) => new ValidationError(f.PropertyName, f.ErrorMessage))
+            .Select(f => Error.Validation(code: f.PropertyName, description: f.ErrorMessage))
             .ToList();
 
         return CreateFailure(errors);
@@ -40,17 +40,14 @@ private static TResponse CreateFailure(List<Error> errors)
     {
         var responseType = typeof(TResponse);
 
-        if (responseType == typeof(Result))
-            return (TResponse)Result.Failure(errors);
-
-        if (responseType.IsGenericType && responseType.GetGenericTypeDefinition() == typeof(Result<>))
+        if (responseType.IsGenericType && responseType.GetGenericTypeDefinition() == typeof(ErrorOr<>))
         {
             var typeArg = responseType.GetGenericArguments()[0];
-            var failureMethod = typeof(Result<>)
+            var implicitOp = typeof(ErrorOr<>)
                 .MakeGenericType(typeArg)
-                .GetMethod(nameof(Result<object>.Failure), [typeof(IReadOnlyList<Error>)])!;
+                .GetMethod("op_Implicit", BindingFlags.Static | BindingFlags.Public, [typeof(List<Error>)])!;
 
-            return (TResponse)failureMethod.Invoke(null, [errors.AsReadOnly()])!;
+            return (TResponse)implicitOp.Invoke(null, [errors])!;
         }
 
         throw new InvalidOperationException($"Unexpected TResponse type: {responseType}");

src/Voltiq.Application/Features/Auth/Commands/Login/LoginCommand.cs

@@ -1,6 +1,6 @@
+using ErrorOr;
 using MediatR;
-using Voltiq.Domain.Common;
 
 namespace Voltiq.Application.Features.Auth.Commands.Login;
 
-public sealed record LoginCommand(string Email, string Password) : IRequest<Result<LoginResponse>>;
+public sealed record LoginCommand(string Email, string Password) : IRequest<ErrorOr<LoginResponse>>;

src/Voltiq.Application/Features/Auth/Commands/Login/LoginCommandHandler.cs

@@ -1,12 +1,11 @@
+using ErrorOr;
 using MediatR;
 using Voltiq.Application.Common.Interfaces;
-using Voltiq.Domain.Common;
 using Voltiq.Domain.Entities;
 using Voltiq.Domain.Interfaces;
 using Voltiq.Domain.Interfaces.Repositories;
 using Voltiq.Domain.Interfaces.Repositories.User;
 using Voltiq.Domain.ValueObjects;
-using Voltiq.Exceptions.Errors;
 using Voltiq.Exceptions.Resources;
 
 namespace Voltiq.Application.Features.Auth.Commands.Login;
@@ -17,17 +16,16 @@ public sealed class LoginCommandHandler(
     ITokenService tokenService,
     IRefreshTokenRepository refreshTokenRepository,
     IUnitOfWork unitOfWork)
-    : IRequestHandler<LoginCommand, Result<LoginResponse>>
+    : IRequestHandler<LoginCommand, ErrorOr<LoginResponse>>
 {
-    public async Task<Result<LoginResponse>> Handle(LoginCommand request, CancellationToken cancellationToken)
+    public async Task<ErrorOr<LoginResponse>> Handle(LoginCommand request, CancellationToken cancellationToken)
     {
         var email = Email.Create(request.Email).Value;
 
         var user = await userRepository.GetByEmailAsync(email, cancellationToken);
 
         if (user is null || !passwordHasher.Verify(request.Password, user.PasswordHash))
-            return Result<LoginResponse>.Failure(
-                new UnauthorizedError(ResourceErrorMessages.LOGIN_CREDENCIAIS_INVALIDAS));
+            return Error.Unauthorized(description: ResourceErrorMessages.LOGIN_CREDENCIAIS_INVALIDAS);
 
         var accessToken = tokenService.GenerateAccessToken(user.Id.ToString(), user.Name, []);
         var rawRefreshToken = tokenService.GenerateRefreshToken();
@@ -36,6 +34,6 @@ public async Task<Result<LoginResponse>> Handle(LoginCommand request, Cancellati
         await refreshTokenRepository.AddAsync(refreshToken, cancellationToken);
         await unitOfWork.SaveChangesAsync(cancellationToken);
 
-        return Result<LoginResponse>.Success(new LoginResponse(accessToken, rawRefreshToken));
+        return new LoginResponse(accessToken, rawRefreshToken);
     }
 }

src/Voltiq.Application/Features/Auth/Commands/Refresh/RefreshTokenCommand.cs

@@ -1,6 +1,6 @@
+using ErrorOr;
 using MediatR;
-using Voltiq.Domain.Common;
 
 namespace Voltiq.Application.Features.Auth.Commands.Refresh;
 
-public sealed record RefreshTokenCommand(string RefreshToken) : IRequest<Result<AuthResponse>>;
+public sealed record RefreshTokenCommand(string RefreshToken) : IRequest<ErrorOr<AuthResponse>>;

src/Voltiq.Application/Features/Auth/Commands/Refresh/RefreshTokenCommandHandler.cs

@@ -1,11 +1,10 @@
+using ErrorOr;
 using MediatR;
 using Voltiq.Application.Common.Interfaces;
-using Voltiq.Domain.Common;
 using Voltiq.Domain.Entities;
 using Voltiq.Domain.Interfaces;
 using Voltiq.Domain.Interfaces.Repositories;
 using Voltiq.Domain.Interfaces.Repositories.User;
-using Voltiq.Exceptions.Errors;
 using Voltiq.Exceptions.Resources;
 
 namespace Voltiq.Application.Features.Auth.Commands.Refresh;
@@ -15,29 +14,25 @@ public sealed class RefreshTokenCommandHandler(
     IUserRepository userRepository,
     ITokenService tokenService,
     IUnitOfWork unitOfWork)
-    : IRequestHandler<RefreshTokenCommand, Result<AuthResponse>>
+    : IRequestHandler<RefreshTokenCommand, ErrorOr<AuthResponse>>
 {
-    public async Task<Result<AuthResponse>> Handle(RefreshTokenCommand request, CancellationToken cancellationToken)
+    public async Task<ErrorOr<AuthResponse>> Handle(RefreshTokenCommand request, CancellationToken cancellationToken)
     {
         var refreshToken = await refreshTokenRepository.GetByTokenAsync(request.RefreshToken, cancellationToken);
 
         if (refreshToken is null)
-            return Result<AuthResponse>.Failure(
-                new UnauthorizedError(ResourceErrorMessages.REFRESH_TOKEN_NAO_ENCONTRADO));
+            return Error.Unauthorized(description: ResourceErrorMessages.REFRESH_TOKEN_NAO_ENCONTRADO);
 
         if (refreshToken.IsExpired)
-            return Result<AuthResponse>.Failure(
-                new UnauthorizedError(ResourceErrorMessages.REFRESH_TOKEN_EXPIRADO));
+            return Error.Unauthorized(description: ResourceErrorMessages.REFRESH_TOKEN_EXPIRADO);
 
         if (!refreshToken.IsActive)
-            return Result<AuthResponse>.Failure(
-                new UnauthorizedError(ResourceErrorMessages.REFRESH_TOKEN_INVALIDO));
+            return Error.Unauthorized(description: ResourceErrorMessages.REFRESH_TOKEN_INVALIDO);
 
         var user = await userRepository.GetByIdAsync(refreshToken.UserId, cancellationToken);
 
         if (user is null)
-            return Result<AuthResponse>.Failure(
-                new UnauthorizedError(ResourceErrorMessages.REFRESH_TOKEN_INVALIDO));
+            return Error.Unauthorized(description: ResourceErrorMessages.REFRESH_TOKEN_INVALIDO);
 
         refreshToken.Revoke();
 
@@ -48,6 +43,6 @@ public async Task<Result<AuthResponse>> Handle(RefreshTokenCommand request, Canc
         await refreshTokenRepository.AddAsync(newRefreshToken, cancellationToken);
         await unitOfWork.SaveChangesAsync(cancellationToken);
 
-        return Result<AuthResponse>.Success(new AuthResponse(newAccessToken, newRawRefreshToken));
+        return new AuthResponse(newAccessToken, newRawRefreshToken);
     }
 }

src/Voltiq.Application/Features/Users/Commands/CreateUser/CreateUserCommand.cs

@@ -1,10 +1,10 @@
+using ErrorOr;
 using MediatR;
-using Voltiq.Domain.Common;
 
 namespace Voltiq.Application.Features.Users.Commands.CreateUser;
 
 public sealed record CreateUserCommand(
     string Name,
     string Email,
     string Document,
-    string Password) : IRequest<Result<CreateUserResponse>>;
+    string Password) : IRequest<ErrorOr<CreateUserResponse>>;

src/Voltiq.Application/Features/Users/Commands/CreateUser/CreateUserCommandHandler.cs

@@ -1,12 +1,11 @@
+using ErrorOr;
 using MediatR;
 using Voltiq.Application.Common.Interfaces;
 using Voltiq.Application.Mappings.Users;
-using Voltiq.Domain.Common;
 using Voltiq.Domain.Entities;
 using Voltiq.Domain.Interfaces;
 using Voltiq.Domain.Interfaces.Repositories.User;
 using Voltiq.Domain.ValueObjects;
-using Voltiq.Exceptions.Errors;
 using Voltiq.Exceptions.Resources;
 
 namespace Voltiq.Application.Features.Users.Commands.CreateUser;
@@ -16,9 +15,9 @@ public sealed class CreateUserCommandHandler(
     IUnitOfWork unitOfWork,
     IPasswordHasher passwordHasher,
     ITokenService tokenService)
-    : IRequestHandler<CreateUserCommand, Result<CreateUserResponse>>
+    : IRequestHandler<CreateUserCommand, ErrorOr<CreateUserResponse>>
 {
-    public async Task<Result<CreateUserResponse>> Handle(CreateUserCommand request, CancellationToken cancellationToken)
+    public async Task<ErrorOr<CreateUserResponse>> Handle(CreateUserCommand request, CancellationToken cancellationToken)
     {
         var email = Email.Create(request.Email).Value;
         var document = Document.Create(request.Document).Value;
@@ -27,7 +26,7 @@ public async Task<Result<CreateUserResponse>> Handle(CreateUserCommand request,
             document, email, cancellationToken);
 
         if (userAlreadyExists)
-            return Result<CreateUserResponse>.Failure(new ConflictError(ResourceErrorMessages.USUARIO_EMAIL_JA_CADASTRADO));
+            return Error.Conflict(description: ResourceErrorMessages.USUARIO_EMAIL_JA_CADASTRADO);
 
         var passwordHash = passwordHasher.Hash(request.Password);
 
@@ -38,6 +37,6 @@ public async Task<Result<CreateUserResponse>> Handle(CreateUserCommand request,
 
         var token = tokenService.GenerateAccessToken(user.Id.ToString(), user.Name, []);
 
-        return Result<CreateUserResponse>.Success(user.ToCreateUserResponse(token));
+        return user.ToCreateUserResponse(token);
     }
 }

src/Voltiq.Application/Features/Users/Queries/GetCurrentUser/GetCurrentUserQuery.cs

@@ -1,6 +1,6 @@
+using ErrorOr;
 using MediatR;
-using Voltiq.Domain.Common;
 
 namespace Voltiq.Application.Features.Users.Queries.GetCurrentUser;
 
-public sealed record GetCurrentUserQuery : IRequest<Result<GetUserResponse>>;
+public sealed record GetCurrentUserQuery : IRequest<ErrorOr<GetUserResponse>>;

src/Voltiq.Application/Features/Users/Queries/GetCurrentUser/GetCurrentUserQueryHandler.cs

@@ -1,31 +1,30 @@
+using ErrorOr;
 using MediatR;
 using Voltiq.Application.Common.Interfaces;
 using Voltiq.Application.Mappings.Users;
-using Voltiq.Domain.Common;
 using Voltiq.Domain.Entities;
 using Voltiq.Domain.Interfaces.Repositories;
-using Voltiq.Exceptions.Errors;
 using Voltiq.Exceptions.Resources;
 
 namespace Voltiq.Application.Features.Users.Queries.GetCurrentUser;
 
 public sealed class GetCurrentUserQueryHandler(
     ICurrentUserService currentUserService,
     IRepository<User> userRepository)
-    : IRequestHandler<GetCurrentUserQuery, Result<GetUserResponse>>
+    : IRequestHandler<GetCurrentUserQuery, ErrorOr<GetUserResponse>>
 {
-    public async Task<Result<GetUserResponse>> Handle(GetCurrentUserQuery request, CancellationToken cancellationToken)
+    public async Task<ErrorOr<GetUserResponse>> Handle(GetCurrentUserQuery request, CancellationToken cancellationToken)
     {
         if (!Guid.TryParse(currentUserService.UserId, out var userId) || userId == Guid.Empty)
-            return Result<GetUserResponse>.Failure(
-                new NotFoundError(string.Format(ResourceErrorMessages.ENTIDADE_NAO_ENCONTRADA, nameof(User), currentUserService.UserId)));
+            return Error.NotFound(description: string.Format(
+                ResourceErrorMessages.ENTIDADE_NAO_ENCONTRADA, nameof(User), currentUserService.UserId));
 
         var user = await userRepository.GetByIdAsync(userId, cancellationToken);
 
         if (user is null)
-            return Result<GetUserResponse>.Failure(
-                new NotFoundError(string.Format(ResourceErrorMessages.ENTIDADE_NAO_ENCONTRADA, nameof(User), userId)));
+            return Error.NotFound(description: string.Format(
+                ResourceErrorMessages.ENTIDADE_NAO_ENCONTRADA, nameof(User), userId));
 
-        return Result<GetUserResponse>.Success(user.ToGetUserResponse());
+        return user.ToGetUserResponse();
     }
 }

src/Voltiq.Application/Voltiq.Application.csproj

@@ -5,6 +5,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="ErrorOr" Version="2.0.1" />
     <PackageReference Include="FluentValidation" Version="12.1.1" />
     <PackageReference Include="FluentValidation.DependencyInjectionExtensions" Version="12.1.1" />
     <PackageReference Include="MediatR" Version="14.0.0" />