Fudie.Validation 1.0.12

Fudie.Validation

Guard patterns and extension methods for validation, exception handling, result unwrapping, and entity lookup validation.

Guards

ValidationGuard

ValidationGuard.ThrowIf(name == "", "Name", "Name is required");
ValidationGuard.ThrowIfNot(age > 0, "Age", "Age must be positive");

Throws FluentValidation.ValidationException with structured errors.

All guards that throw ConflictException, UnauthorizedException, or ValidationException support an ErrorCode overload for structured error identification:

var errorCode = new ErrorCode("Customer", "Slug", "AlreadyExists", "Slug already taken", ErrorCodeCategory.Guard);
ConflictGuard.ThrowIf(slugExists, errorCode);

var nameRequired = new ErrorCode("Customer", "Name", "Required", "{PropertyName} is required");
ValidationGuard.ThrowIf(string.IsNullOrEmpty(name), nameRequired);

ErrorCode

// Category defaults to FluentValidation
var code = new ErrorCode("Customer", "Name", "Required", "{PropertyName} is required");
code.Code // "Customer.Name.Required"

// Guard category must be explicit
var guard = new ErrorCode("Customer", "IsActive", "AlreadyActive", "Already active", ErrorCodeCategory.Guard);

ErrorCodeCategory

NotFoundGuard

NotFoundGuard.ThrowIfNull(entity, entityId);
NotFoundGuard.ThrowIfNull<Order>(entity);
NotFoundGuard.ThrowIfNull<Order, Guid>(entity, orderId);

Throws KeyNotFoundException with formatted messages like "Order with id 'xxx' was not found".

ConflictGuard

ConflictGuard.ThrowIf(isDuplicate, "An order with this number already exists");

Throws ConflictException.

UnauthorizedGuard

UnauthorizedGuard.ThrowIf(!isOwner, "Only owners can perform this action");

Throws UnauthorizedException.

Result Extensions

Result<Order> result = CreateOrder(command);
Order order = result.ValueOrThrow();   // Throws ValidationException if failed
result.SuccessOrThrow();                // Throws ValidationException if failed (no value)

Validator Extensions

await validator.ValidateOrThrow(command);

Validates using FluentValidation and throws on failure. Also checks for empty Guids.

Public Types

Dependencies

• FluentValidation
• Fudie.Domain