public async void DeleteContratoTeste() { CriarMultiplosContratos(_options); // Use a clean instance of the context to run the test using (var context = new DataContext(_options)) { ContratoService contrato = new ContratoService(context); await contrato.DeleteContratoService(1); await Assert.ThrowsAsync <ArgumentNullException>( async() => await contrato.GetContratoService(1) ); } }