NUnit ExpectedException Bug in 2.4.7

"Bug In NUnit ? It can't be!" Exactly my words ; However it turned out that the behavior is due to a newer NUnit runner (Gui v 2.5.3) running a test fixture referencing an older version of NUnit.Framework.dll (v2.4.7)

Try this in a NUnit test fixture referencing NUnit.Framework v 2.4.7

// 2.4.7 - test passes even if an exception of wrong type is thrown
        [ExpectedException(ExceptionType=typeof(FileNotFoundException))]
        [Test]
        public void Test_ExpectedException()
        {
            throw new ArgumentException();
        }

I found that the test passes if "any" exception is thrown. It doesn't have to match the specified type. A false positive!

To fix this, upgrade your NUnit version to 2.5.2. You'd also need to fix a compile error. 'ExceptionType' property has now become ExpectedException.

//2.5.2 'works as expected'
        [ExpectedException(ExpectedException=typeof(FileNotFoundException))]
        [Test]
        public void Test_ExpectedException()
        {
            throw new ArgumentException();
        }

You live... you learn.