BadRequestException

Namespace: RA.Utilities.Core.Exceptions

BadRequestException represents a failure caused by invalid client-side input. The API layer maps it to HTTP 400 Bad Request.

🎯 Purpose

This is the primary tool for validation errors discovered inside business logic (for example, in a CQRS handler or application service). Instead of a generic exception with a single string, BadRequestException carries a structured array of ValidationError items so the client can see exactly which fields failed and why.

Use it when the request itself is invalid. When the request is well formed but the resource state prevents the operation, use UnprocessableException instead.

Properties

Property	Type	Description
Errors	ValidationError[]	The validation failures that caused the exception.
ErrorCode	int	Inherited. 400 unless supplied explicitly.
ResponseType	ResponseType	Inherited. ResponseType.BadRequest.
Message	string	Inherited. BaseResponseMessages.BadRequest ("The request is invalid.") unless supplied explicitly.

Each ValidationError exposes PropertyName, ErrorMessage, AttemptedValue, ExpectedValue, and a custom ErrorCode.

Constructors

Constructor	ErrorCode	Message
BadRequestException(ValidationError error)	400	BaseResponseMessages.BadRequest
BadRequestException(ValidationError error, int errorCode, string? message = null)	supplied	supplied, or BaseResponseMessages.BadRequest when null/omitted
BadRequestException(ValidationError[] errors)	400	BaseResponseMessages.BadRequest
BadRequestException(ValidationError[] errors, int errorCode, string? message = null)	supplied	supplied, or BaseResponseMessages.BadRequest when null/omitted

There is no message-only constructor: a ValidationError is always required.

🚀 How to Use

Example: Using with FluentValidation

Catch a FluentValidation ValidationException and convert its failures into ValidationError items:

using FluentValidation;
using RA.Utilities.Core.Results;
using RA.Utilities.Core.Exceptions;

public async Task<Result<UserDto>> CreateUserAsync(CreateUserCommand command)
{
    try
    {
        await _validator.ValidateAndThrowAsync(command);
    }
    catch (ValidationException ex)
    {
        ValidationError[] validationErrors = [.. ex.Errors.Select(e => new ValidationError(e.ErrorMessage)
        {
            PropertyName = e.PropertyName,
            AttemptedValue = e.AttemptedValue,
            ErrorCode = e.ErrorCode
        })];

        return new BadRequestException(validationErrors);
    }

    // ... continue with user creation logic if validation passes
}

Example: A single validation error

using RA.Utilities.Core.Constants;
using RA.Utilities.Core.Exceptions;

if (string.IsNullOrWhiteSpace(request.Email))
{
    throw new BadRequestException(new ValidationError(BaseErrorMessage.EmailRequired)
    {
        PropertyName = "Email",
        ErrorCode = BaseErrorCode.EmailRequired
    });
}

Example: Attach a request-level code and message

return new BadRequestException(
    errors: validationErrors,
    errorCode: 4001,
    message: "The registration form is invalid."
);

🔗 HTTP mapping

ErrorResultResponse maps BadRequestException to HTTP 400 with a BadRequestResponse whose result is an array of the exception's Errors. The ErrorCode is echoed into responseCode; it does not change the HTTP status.

See BadRequestResponse for the exact JSON shape and the ValidationError reference for each item's fields.