public void BuildFeedItemByGenreUrl_ReturnsUrl() { var boomkatConfigurationFake = A.Fake <IBoomkatConfiguration>(); A.CallTo(() => boomkatConfigurationFake.FeedItemByGenreUrlFormat).Returns("http://boomkat.com/genres/{1}/summary/page/{0}"); var urlBuilder = new UrlBuilder(boomkatConfigurationFake); var url = urlBuilder.BuildFeedItemByGenreUrl(2, 1); Assert.That(url, Is.EqualTo("http://boomkat.com/genres/2/summary/page/1")); }