public void RefreshPackagesTest() { Mock <Repository> repo_mock = new Mock <Repository>(); Mock <Upset> package_dummy_old = new Mock <Upset>(); Mock <Upset> package_dummy_recent = new Mock <Upset>(); PackageRepo old_pr = new PackageRepo { Package = package_dummy_old.Object, Repository = repo_mock.Object }; PackageRepo recent_pr = new PackageRepo { Package = package_dummy_recent.Object, Repository = repo_mock.Object }; repo_mock.Setup(repo => repo.ListPackages()).Returns(new Upset[] { package_dummy_recent.Object }); (pl as PackageListTester).SetPackages(new List <PackageRepo> { old_pr }); (pl as PackageListTester).SetRepositories(new Repository[] { repo_mock.Object }); pl.RefreshPackages(); List <PackageRepo> result = (pl as PackageListTester).GetPackages(); CollectionAssert.DoesNotContain(result, old_pr); CollectionAssert.Contains(result, recent_pr); }