ValidationError

Namespace: RA.Utilities.Core.Exceptions

ValidationError describes a single validation failure. It is the element type of BadRequestException.Errors, not an exception itself.

🎯 Purpose

A BadRequestException can report several failures at once. ValidationError gives each failure the context a client needs to fix it: which property failed, what was submitted, what was expected, and a stable machine-readable code.

The API layer projects these items directly into the result array of a BadRequestResponse.

Properties

Property	Type	Required	Description
`ErrorMessage`	`string`	✅ constructor argument	Human-readable description of the failure.
`PropertyName`	`string?`	❌	Name of the property that failed validation (e.g., `"Email"`). Omitted from JSON when `null`.
`AttemptedValue`	`object?`	❌	Value supplied by the client that caused the failure. Omitted from JSON when `null`.
`ExpectedValue`	`object?`	❌	Value or shape that was expected, when applicable. Omitted from JSON when `null`.
`ErrorCode`	`string?`	❌	Machine-readable code for the failure (e.g., `"REQUIRED_EMAIL"`). Omitted from JSON when `null`.

All properties use { get; init; }. ErrorMessage is set through the constructor; the others are optional object-initializer values.

Constructors

Constructor	Description
`ValidationError(string errorMessage)`	Creates an error with the required message. All other properties start as `null`.

🚀 How to Use

Example: Build a structured error

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

var error = new ValidationError(BaseErrorMessage.EmailRequired)
{
    PropertyName = "Email",
    AttemptedValue = request.Email,
    ExpectedValue = "a valid email address",
    ErrorCode = BaseErrorCode.EmailRequired
};

return new BadRequestException(error);

Example: Map FluentValidation failures

ValidationError[] errors = [.. ex.Errors.Select(e => new ValidationError(e.ErrorMessage)
{
    PropertyName = e.PropertyName,
    AttemptedValue = e.AttemptedValue,
    ErrorCode = e.ErrorCode
})];

return new BadRequestException(errors);

📦 JSON shape

When mapped by RA.Utilities.Api, each item is serialized with camelCase names; null properties are omitted:

{
  "propertyName": "EmailAddress",
  "errorMessage": "'Email Address' is not a valid email address.",
  "attemptedValue": "not-an-email",
  "errorCode": "EmailValidator"
}

See BadRequestResponse for the full response envelope and BaseErrorCode for the standard codes.

🎯 Purpose​

Properties​

Constructors​

🚀 How to Use​

Example: Build a structured error​

Example: Map FluentValidation failures​

📦 JSON shape​