How to Unit Test Data Annotation Validators

Question

I'm implementing the Data Validation Validators as shown here:

http://www.asp.net/learn/mvc/tutorial-39-cs.aspx

This works great at runtime, but how can I Unit Test to verify if I say attribute [StringLength(10)], an error is retured?

Regards.

Answer 1

Brad Wilson describes it pretty well in a blog post from a while ago (you'll have to scroll down a bit). Basically, you write tests where you use reflection to make sure that the proper attributes are applied, and then trust the framework to do its job on adding errors. After all, someone else tested the Data Annotation Validators before they were published - you just have to make sure you use them right =)

Answer 2

This post by Villecoder is the unit testing solution I'm using. It also allows you unit unit test custom annotations

http://villecoder.com/2010/04/23/unit-testing-custom-data-annotations/