Mvc: Unit Testing Page Model Throws Null Ref On ModelState check

Created on 12 Oct 2017 · 9Comments · Source: aspnet/Mvc

While testing Razor Pages, when I create a new PageModel, it throws a null reference exception when doing the ModelState.IsValid check. The NRE is on ModelState itself.

This seems to be a change from the way MVC's ModelState "just worked" when newing up the controller.

For instance (some Arrange code removed for brevity)...

In MVC:

var controller = new AccountController(dependency1, dependency2);
var result = await controller.Login(new LoginViewModel()));
// **Does NOT** throw NRE on ModelState.IsValid check

In Razor Pages:

var loginModel = new LoginModel(dependency1, dependency2);
var result = await loginModel.OnPostAsync();
// **DOES** throw NRE on ModelState.IsValid check, because ModelState is null.

This is bit of an annoyance.

/cc @DamianEdwards

3 - Done bug

Source

scottsauber

All 9 comments

You should be able to work around this for now by instantiating a PageContext and setting it.

We should fix this, all of this stuff needs to 'just work'. It looks like there are a few more properties that delegate to PageModel, but they need to work well in unit test scenarios like Controller does.