如何使这个单元可测试

Question

Below I have some code that that I cannot Unit test because it tries to read settings from IIS7 and unfortunately our nightly build machine does not have IIS7. The only thing I can think of is to pass the ServerManager into the method, but then again in the caller I will have a ServerManager that will make that method unable to be unit tested. We use MOQ for our Mock library.

        public ISection GetCurrentSettings(string location, Action<string> status)
    {
        #region Sanity Checks

        if (string.IsNullOrEmpty(location))
        {
            throw new ArgumentNullException("location");
        }
        if (status == null)
        {
            throw new ArgumentNullException("status");
        }
        #endregion

        ISection section = null;

        _logger.Debug(string.Format("Retrieving current IIS settings for app at {0}.", location));
        status("Getting current IIS settings.");
        using (ServerManager manager = new ServerManager())
        {
            var data = (from site in manager.Sites
                        from app in site.Applications
                        from vdir in app.VirtualDirectories
                        where vdir.PhysicalPath.Equals(location, StringComparison.CurrentCultureIgnoreCase)
                        select new {Website = site, App = app}).SingleOrDefault();

            if (data == null)
            {
                _logger.Debug(string.Format("Could not find an application at {0} in IIS. Going to load the defaults instead.", location));
                //ToDo possibly load defaults
            }
            else
            {
               _logger.Debug(string.Format("Application found in IIS with website: {0} and a path of {1}", data.Website.Name, data.App.Path));
                int port =
                    data.Website.Bindings.Where(b => b.EndPoint != null).Select(b => b.EndPoint.Port).Single();


                section = new IISSection
                    {
                        ApplicationPoolName = data.App.ApplicationPoolName,
                        VirtualDirectoryAlias = data.App.Path,
                        WebsiteName = data.Website.Name,
                        WebsiteRoot = data.App.VirtualDirectories[0].PhysicalPath,
                        Port = port.ToString(CultureInfo.InvariantCulture),
                        WillApply = true,
                        AnonymousUser = _userService.GetUserByType(UserType.Anonymous)
                    };
            }

            return section;

        }

Answer 1

Without rewriting your code fully, the general idea would be to pass in an ISettingReader* (implemented as IisSettingReader), which would expose methods that would get the data you need from IIS. Then, you can stub in the ISettingReader to return what you need, by passing ISettingReader into the method/class

*Or, IServerManager as it seems to be the current name, but I am not sure if that is IIS specific

UPDATE

To be more specific, as Darin Dimitrov elaborated, you need to pull all of the dependencies outside of the method and pass them in via parameter/constructor/property injection. This will require a rewrite of the code as it stands in its current state.

If not (and I do suggest a rewrite), then you can use something like TypeMock, which supposedly can fake the dependencies INSIDE a class, but I have not used this myself and only know what I have read on it.

Answer 2

Use Moq .

This will allow you to create a mocked version of ISettings rather than having to create a real one. It has the added advantage of allowing you to specify your own functionality as well.