Fluent validation against a group of properties

Is there a way to specify more than one property as part of a rule so that they can all be checked at the same time, probably as part of a custom validator. Something like

RuleFor(f => f.ProductA).AndFor(f => f.ProductB).AndFor(f => ProductC).Must(AtLeastOneProduct).WithMessage("Select at least one product")

private bool AtLeastOneProduct(bool productA, bool productB, bool productC)
{
    return productA || productB || productC; 
}

Which would execute once and product a error for each of the properties.

[JeremySkinner]

So the ShouldHaveValidationErrorFor method is for testing against properties. As you’re using a model level rule you can’t use this method- you should execute the Validate method directly and run your assertions on the returned ValidationResult (you can iterate over the Errors collection to find if any errors match this case, I’d tend to use the PropertyName to identify the appropriate error, which I believe will just be an empty string for model-level rules).

Edit: In this case, as you’ve used WithName you can actually find based on PropertyName = Destination. Example:

[Fact]
public void Example() {
    var validator = new ContentMenuValidator();
    var result = validator.Validate(new ContentMenu {Id = 1, Text = "Test", PageId = null, Url = null});

    // Find the validation result with the expected error
    var matchingErrors = result.Errors.Where(x => x.PropertyName == "Destination").ToList();
    Assert.Equal(1, matchingErrors.Count);
    Assert.Equal("You must select a page or enter a URL for a menu", matchingErrors[0].ErrorMessage);
       // .... other assertions etc. 
}

Hope that helps

[LeahPike]

I’ve added a rule against the entire model to handle the user having to have one of two properties populated.

RuleFor(e => e).Must(e => e.PageId.HasValue || !string.IsNullOrEmpty(e.Url)).WithName("Destination").WithMessage("You must select a page or enter a URL for a menu");

How do I run a test against this?

_validator.ShouldHaveValidationErrorFor(e => e, new ContentMenu { Id = 1, Text ="Test", PageId = null, Url = null });

It doesn’t like the above.