Exception has been thrown by the target of an invocation

Hi,

I'm trying to write a test case where I need to mock XmlTextReader, XmlDocument and XmlNode (well, at least I think I need to mock these things)

We've a class called ShiftInfo whose constructor loads global configuration file (which is actually a plain XML document) and reads a connection string (and of course some other information) and initializes the instance.

// constructor's sample code
public ShiftInfo()
{
  XmlTextReader reader = new XmlTextReader("http://server/config.xml");
  XmlDocument doc = new XmlDocument();
  doc.Load(reader);
  _someConnString = doc.SelectSingleNode("/ConnectionStringToDB").InnerXml;
  reader.Close();
}

We are using NUnit to do the unit testing and evaluating TypeMock.
The very first test case we have is supposed to mock that file exists on the server. It also tries to mock that file has expected node.

// First test case to mock file exists and file has expected node
public ConstructorTest()
{
  string expectedConnectionString = "Data Source=;Database;User Id=;Password=";
  
  MockObject mockedNode = MockManager.MockObject(typeof(XmlNode), Constructor.NotMocked);
  mockedNode.ExpectGet("InnerXml", expectedConnectionString);
  XmlNode xmlNode = (XmlNode)mockedNode.Object;
  
  MockObject mockedDoc = MockManager.MockObject(typeof(XmlDocument));
  mockedDoc.ExpectCall("Load", typeof(XmlReader));
  mockedDoc.ExpectAndReturn("SelectSingleNode", xmlNode).Args("/ConnectionStringToDB");
  
  ShiftInfo si = new ShiftInfo();

  Assert.AreEqual(expectedConnectionString, si.ConnectionString);
}

Now, I must agree as a test this code does not make any sense at all. But, when I try to run, I get the following exception


Nucor.Hickman.Web.NHSystem.HeaderShiftInfo.Tests.ShiftInfoTests.Constructor : System.Reflection.TargetInvocationException : Exception has been thrown by the target of an invocation.
----> System.MethodAccessException : System.Xml.XmlNode..ctor()


AND


at System.RuntimeMethodHandle._InvokeConstructor(Object[] args, SignatureStruct& signature, IntPtr declaringType)
at System.RuntimeMethodHandle.InvokeConstructor(Object[] args, SignatureStruct signature, RuntimeTypeHandle declaringType)
at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at TypeMock.MockManager.MockObject(Type type, Constructor mockConstructors, Object[] args)
at Nucor.Hickman.Web.NHSystem.HeaderShiftInfo.Tests.ShiftInfoTests.Constructor() in C:dotNetNucorHickmanWebNHSystemHeaderShiftInfoNucor.Hickman.Web.NHSystem.HeaderShiftInfoTestsShiftInfoTests.cs:line 69
--MethodAccessException
at MockXmlNode..ctor()


I searched for this error and I found couple of posts from 2005 that suggested that the support has been added to precompiled libraries in the newer versions. So, I'm guessing there is something that I'm doing and I'm doing it terribly wrong.

In my deference, this is my first time in using mock objects and whole mocking thing :wink:

If you could just point me in the right direction that would suffice too... But, of course more detailed explanation or examples would be great

Thanks,