public void AddFile_NewFile_AddsFileToFileSystem()
        {
            CreateTestProject();
            CreateProjectSystem(project);

            string expectedPath   = @"d:\temp\abc.cs";
            Stream expectedStream = new MemoryStream();

            projectSystem.AddFile(expectedPath, expectedStream);

            Assert.AreEqual(expectedPath, projectSystem.PathPassedToPhysicalFileSystemAddFile);
            Assert.AreEqual(expectedStream, projectSystem.StreamPassedToPhysicalFileSystemAddFile);
        }
 void AddFile(string fileName)
 {
     projectSystem.AddFile(fileName, (Stream)null);
 }