public void HowToMockMembershipProvider() { // create fake membership user var user = new Sitecore.FakeDb.Security.Accounts.FakeMembershipUser(); // create membership provider mock var provider = NSubstitute.Substitute.For<System.Web.Security.MembershipProvider>(); provider.GetUser(@"extranet\John", true).Returns(user); // switch the membership provider using (new Sitecore.FakeDb.Security.Web.MembershipSwitcher(provider)) { // check if the user exists var exists = Sitecore.Security.Accounts.User.Exists(@"extranet\John"); Xunit.Assert.True(exists); } }