public void AddValue_AddAccountToEmptyList() { //Arrange var Mockservice = new Mock <IApiRequestSend <BankAcount> >(); BankAccountController BAC = new BankAccountController(Mockservice.Object); BankAcount B = new BankAcount { Personnummer = 940806 }; //Act BAC.AddAcount(B); Assert.Single(BAC.TheAcount); Mockservice.Verify(m => m.AddEntity(It.IsAny <BankAcount>()), Times.Once); }