FluentValidation NotEmpty message is not showing

Question

For example, FluentValidation validates an empty email address that a user inputs.

I chained two functions but it skips the .NotEmpty().WithMessage() and jumps to the next which is EmailAddress().WithMessage().

RuleFor(r => r.EmailAddress)
                .NotEmpty().WithMessage("Email address is required.")
                .EmailAddress().WithMessage("Email address is not valid.");

Why is that the error message is "Email address is not valid." while the first in chain is "Email address is required."?

Answer 1

This is because the last condition is always verified, even if the first rule fails. Try setting the CascadeMode, as described in the documentation, like this:

RuleFor(r => r.EmailAddress)
    .Cascade(CascadeMode.StopOnFirstFailure)
    .NotEmpty().WithMessage("Email address is required.")
    .EmailAddress().WithMessage("Email address is not valid.");