How to mock application path when unit testing Web App

Question

I am testing code in a MVC HTML helper that throws an error when trying to get the application path:

//appropriate code that uses System.IO.Path to get direc         


        

Answer 1

As an alternative to mocking built-in .net classes, you can

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

public class PathProvider : IPathProvider
{
    private readonly HttpServerUtilityBase _server;

    public PathProvider(HttpServerUtilityBase server)
    {
        _server = server;
    }

    public string GetAbsolutePath(string path)
    {
        return _server.MapPath(path);
    }
}

Use the above class to get absolute paths.

And for For unit testing you can mock and inject an implementation of IPathProvider that would work in the unit testing environment.

--UPDATED CODE