Unit testing for Server.MapPath

Question

I\'ve a method. which retrieve a document from hard disk. I can\'t test this from unit testing. It always throw an exception invalid null path or something. How to test that

Answer 1

You can use dependancy injection and abstraction over Server.MapPath

public interface IPathProvider
{
   string MapPath(string path);
}

And production implementation would be:

public class ServerPathProvider : IPathProvider
{
     public string MapPath(string path)
     {
          return HttpContext.Current.Server.MapPath(path);
     }
}

While testing one:

public class TestPathProvider : IPathProvider
{
    public string MapPath(string path)
    {
        return Path.Combine(@"C:\project\",path);
    }
}