** Project changed: nunitv2 => nunit-3.0
--
You received this bug notification because you are a member of NUnit
Developers, which is subscribed to NUnit V2.
https://bugs.launchpad.net/bugs/1157828
Title:
EqualityComparer does not respect value-equality for null
Status in NUnit Test Framework:
Triaged
Bug description:
I am using a third-party library that includes Null Objects with value
comparisons that return true for null. However, the NUnit equality
comparer uses reference equality (via the == operator with
System.Object references) to check for null and returns false if only
one input is the null pointer. This means that the value-equality
comparison for the custom type is never reached.
The following is a quick & dirty implementation of a Null Object with
a few tests that demonstrate the problem:
public class MyObject
{
public static MyObject NullObject = new MyObject(-1);
public int Value { get; set; }
public MyObject(int value)
{
this.Value = value;
}
public static bool operator ==(MyObject left, MyObject right)
{
if (ReferenceEquals(left, NullObject) || ReferenceEquals(left, null))
return (ReferenceEquals(right, NullObject) ||
ReferenceEquals(right, null));
else if (ReferenceEquals(right, NullObject) || ReferenceEquals(right,
null))
return false;
return Equals(left, right);
}
public static bool operator !=(MyObject left, MyObject right)
{
return !(left == right);
}
public override bool Equals(object obj)
{
if (ReferenceEquals(obj, NullObject) || ReferenceEquals(obj, null))
return (ReferenceEquals(this, NullObject));
else if (ReferenceEquals(this, NullObject))
return false;
MyObject myobj = obj as MyObject;
if (myobj == null)
return false;
return this.Value == myobj.Value;
}
public override int GetHashCode()
{
return base.GetHashCode();
}
}
[TestFixture]
public class TestNullObject
{
// TEST PASSES
[Test]
public void TestIsTrue()
{
Assert.IsTrue(MyObject.NullObject == null);
Assert.IsTrue(null == MyObject.NullObject);
}
// TESTS FAIL
[Test]
public void TestIsNull()
{
Assert.IsNull(MyObject.NullObject);
}
[Test]
public void TestAreEqual1()
{
Assert.AreEqual(MyObject.NullObject, null);
}
[Test]
public void TestAreEqual2()
{
Assert.AreEqual(null, MyObject.NullObject);
}
}
To manage notifications about this bug go to:
https://bugs.launchpad.net/nunit-3.0/+bug/1157828/+subscriptions
_______________________________________________
Mailing list: https://launchpad.net/~nunit-core
Post to : nunit-core@lists.launchpad.net
Unsubscribe : https://launchpad.net/~nunit-core
More help : https://help.launchpad.net/ListHelp
