Mocking Stream.Read using moles?

Question

I need to unit test the following method . I need to mock the stream object . When I use MStream ,

 

MStream a = new MStream();

a.ReadByte = () => ;

 

Test is failing since MStream() object cannot be created as it is abstract class (object creation is not possible). I tried assigning MFileStream Object to it but type doesn’t allow . Is there a way to mock this stream.Read?

 

    public static bool IsAssemblyDownloaded(string assemblyFile, Stream stream)

        {

            bool status = false;

            using (var file = new FileStream(assemblyFile, FileMode.Create, FileAccess.ReadWrite))

            {

                var buffer = new byte[ConstMaxBufferSize];

                if (buffer.Length > 0)

                {

                    int count;

                    while ((count = stream.Read(buffer, 0, buffer.Length)) > 0)

                    {

                        file.Write(buffer, 0, count);

                        file.Flush();

                    }

 

                    stream.Close();

                    file.Position = 0;

                    status = true;

                }

            }

 

            return status;

        }

Answer 1

You cannot assign an MFileStream to a MStream (although this is something we could think about doing). You should have access to an MStream (and the Read) method by calling the .BaseMembers property:

   var fs = new MFileStream();
   MStream ms = fs.BaseMembers;


If the .BaseMembers property is not present, instantiate a MStream instance around the MFileSystem runtime instance:

   var fs = new MFileStream();
   var ms = new MStream(fs.Instance);

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Jonathan "Peli" de Halleux - Give us your input about Pex!