public void ShouldNot_ValidateTeam_ForGreaterThanDimensionInput() { //arrange int dimensions = 2; int teamId = 2; IMatrixProvider matrixProvider = A.Fake <IMatrixProvider>(); IValidatorService validatorService = new ValidatorService(matrixProvider); A.CallTo(() => matrixProvider.GetDimensions()).Returns(dimensions); //act Action action = () => validatorService.ValidateTeam(teamId); //assert action.Should().Throw <InvalidTeamIndexException>(); }