c# - FluentValidation rule for multiple properties

Question

I have a FluentValidator that has multiple properties like zip and county etc. I want to create a rule that takes two properties just like a RuleFor construct

public class FooArgs
{
    public string Zip { get; set; }
    public System.Guid CountyId { get; set; }
}

public class FooValidator : AbstractValidator<FooArgs>
{
    RuleFor(m => m.CountyId).Must(ValidZipCounty).WithMessage("wrong Zip County");
}

This works but I want to pass both Zip and county to the rue in order to validate. What is the best method to achieve this?

Answer 1

There is a Must overload that also provides you with the FooArgs object documented here. It allows you to easily pass both arguments into your method like this:

RuleFor(m => m.CountyId).Must((fooArgs, countyId) =>
    ValidZipCounty(fooArgs.Zip, countyId))
    .WithMessage("wrong Zip County");