public void ShouldParseExpressionAndEvaluateResult()
        {
            _helper.Expect(c => c.ParseExpression("2/3 + 4/5")).Return("22/15");
            _model = new ExpressionModel
            {
                Expression = "2/3 + 4/5"
            };
            var actionResult = _controller.Index(_model) as ViewResult;

            _helper.VerifyAllExpectations();
            Assert.IsNotNull(actionResult);

            var model = actionResult.Model as ExpressionModel;

            Assert.IsNotNull(model);
            Assert.AreEqual("22/15", model.Result);
        }
        public void ShouldParseExpressionAndThrowException()
        {
            _helper.Expect(c => c.ParseExpression("2/3 ~ 4/5")).Throw(new Exception("Invalid Expression Syntax!"));
            _model = new ExpressionModel
            {
                Expression = "2/3 ~ 4/5"
            };
            var actionResult = _controller.Index(_model) as ViewResult;

            _helper.VerifyAllExpectations();
            Assert.IsNotNull(actionResult);

            var model = actionResult.Model as ExpressionModel;

            Assert.IsNotNull(model);
            Assert.AreEqual("Invalid Expression Syntax!", model.Result);
        }
 public ActionResult Index()
 {
     ViewBag.Title = "Home Page";
     ExpressionModel model = new ExpressionModel();
     return View(model);
 }