Thanks to Roy’s suggestion, I added an overload to the FileAssert class that takes the filename as a string (well actually two, since there is always a method that takes the error message to be displayed as a string). This avoids you having to create FileInfo or FileStream objects if you already have the files on disk. I should have realized this since I had to setup FileInfo and FileStream objects for all my tests by reading files from disk already.
static public void AreEqual(string expected, string actual, string message)
Download the FileAssert class (it’s in the NUnitIO release) from the NUnitExtensions workspace.