NUnit Assert.AreEqual（对象a，对象b）假否定？

Question

I can't understand why NUnit Assert.AreEqual is failing.

var dataService = new DataService(db);
dataService.Set("Tests", "circle1", circle);
var circleData = dataService.Get("Tests", "circle1");
Assert.IsNotNull(circleData);
var circleCopy = circleData.Get();
Assert.AreEqual(circle, circleCopy);

Using NHibernate (storing serialized data, then deserializing it). I've inserted a breakpoint and inspected the objects in Local variables window -- they are identical.

Here is the NUnit message:

Assert.AreEqual failed. Expected:<TestData.TestClassCircle>. Actual:<TestData.TestClassCircle>.

Why would this test be failing when the objects appear to be identical?

Answer 1

What is CircleData ? Does it override Equals ? Looks to me like you're cloning it, which means that you've got two separate CircleData instances. Unless CircleData overrides Equals , then it will be performing a reference equality check, which will fail.

Answer 2

It is not clear what is this dataService of yours doing behind the scenes but if it is serializing/deserializing you won't get same object references. AreEqual compares object references in memory and not values.

Answer 3

Probably your Object doesn't implement Object.Equals correctly.

http://msdn.microsoft.com/en-us/library/bsc2ak47.aspx