title: Can't mock unitOfWork and no interfaces of services
body: <p>I have the following classes</p>
  
  <pre><code>namespace Foo.Bar.Services    
  {    
      public abstract class Service    
      {    
          public Service(IUnitOfWork unitOfWork)    
          {    
              this.UnitOfWork = unitOfWork;    
          }
          protected IUnitOfWork UnitOfWork { get; private set; }    
      }  
  }
  
  using...
  
  namespace Foo.Bar.Services    
  {    
      public class ControlService : Service    
      {    
          ...    
          private readonly IRepository&lt;GroupStructure&gt; groupStructures = null;
  
          public ControlService(IUnitOfWork uow) : base(uow)
          {    
             ...
             this.agencyGroupStructures = this.UnitOfWork.GetRepository&lt;AgencyGroupStructure&gt;();    
          }
  
          public Tuple&lt;bool, int&gt; HasExternalImage(int branchId)
          {
              var externalResultList = from a in this.Structures.Table
                                      where a.GroupID == branch.GroupID
                                          &amp;&amp; (a.AreExternalRequired == true)
                                          &amp;&amp; (a.ProductTypeID == ETourType.Trailer)
                                          &amp;&amp; !a.Deleted
                                      select a;
              return (some logic based on above...)
          }    
  }
  </code></pre>
  
  <p>and test</p>
  
  <pre><code>namespace ControlTests    
  {    
      [TestFixture]    
      public class Control    
      {    
          //unable to create service due to being abstact  
          [Test]    
          public void TestMethod1()    
          {    
              ******Changed here******
              var Mock = new Mock&lt;GroupStructureService&gt; { CallBase = true };    
              var fakeControl = new ControlService(Mock.Object)
  
              var sut = fakeControl.HasExternalImage(1249);
  
              Assert.That(sut.Item1, "true");    
          }    
      }    
  }
  </code></pre>
  
  <p>Running the above with NUnit and Moq gives the following message: </p>
  
  <blockquote>
    <p>Castle.DynamicProxy.InvalidProxyConstructorArgumentsException : Can
    not instantiate proxy of class: Foo.Bar.Services.ControlService.<br>
    Could not find a parameterless constructor.</p>
  </blockquote>
  
  <p>I've tried a few things but I can't get this previously untested app to create a mock object to test</p>
  
  <blockquote>
    <p>Edit, thanks.  So I've changed it to use the ControlService and mock 1
    dependancy.  But its error is that it cant convert from
    ....GroupStructure to Foo.Bar.IUnitOfWork</p>
  </blockquote>