public void GetByDocument() { var mockClientR = new Mock <IClientRepository>(); ClientBusiness clientBusiness = new ClientBusiness(mockClientR.Object); var client = new Client() { Code = "3255d0c982054e1d8d1301ec31039ea3", Name = "Wesley Simplicio", Document = 41343850835, Email = "*****@*****.**", Status = StatusEnum.Active, CreateAt = new DateTime(2019, 12, 08) }; mockClientR.Setup(p => p.GetByDocument(client.Document)).Returns(client); var result = clientBusiness.GetByDocument(41343850835); Assert.IsTrue(result != null); }