public void EnsureGenerateHashInvokesCryptoServiceComputeOperation()
{
var cryptoService = A.Fake <ICryptoService>();
var service = new PasswordEncryptor(cryptoService);
const string salt = "salt";
const string password = "******";
service.GenerateHash(password, salt);
A.CallTo(() => cryptoService.Compute(password, salt))
.MustHaveHappened(Repeated.Exactly.Once);
}