Mocking FindControl in ASP.NET Web Forms

Hello,

I have this test setup:

var targetLabel = new Label { ID = "label" };

var p = Isolate.Fake.Instance<Panel>();
Isolate.WhenCalled(() => p.ID).WillReturn("panel");
p.Controls.Add(targetLabel);
p.Controls.Add(new TextBox { ID = "text" });

var p2 = Isolate.Fake.Instance<Panel>();
Isolate.WhenCalled(() => p2.ID).WillReturn("panel2");
p2.Controls.Add(new Label { ID = "label2" });
p2.Controls.Add(new TextBox { ID = "text2" });
p.Controls.Add(p2);

Isolate.WhenCalled(() => p2.FindControl("label")).WithExactArguments().WillReturn(null);
Isolate.WhenCalled(() => p.FindControl("label")).WithExactArguments().WillReturn(targetLabel);

This is for a processing component that loops through the structure. As it loops through the structure, I want, when it gets to the p2 element, to return null, which will continue the looping, but when p is hit, it will return a match, which gets returned to the caller.

The issue is, FindControl returns a control, so it doesn't actually return a targetLabel; the assert;

Assert.IsInstanceOf<Label>(result)

Fails because the FindControl() method returns a faked control instance,not my targetLabel control reference.... so how can I mock FindControl, because the issue is its referring to all the controls as Control, and not their respective types.

Thanks.

Hi,

Basically, you can use WillReturn() to return a derived type and the assertion should work. What's throwing me off in your code is this usage:

var p = Isolate.Fake.Instance<Panel>();
p.Controls.Add(x)...

Considering that p is a recursive fake, any calls originating from it are fake as well, meaning p.Controls.Add() doesn't do anything. Is this necessary for what you're trying to test?

Doron
Typemock Support

ok

Doron,

True, good point :-) I had actual objects at first, then switched them to fakes for some reason... wasn't thinking I guess. Anyway, originally I was getting errors but now it seems to work. Awesome.

Thanks.