public ActionResult Get(string expr, int?precision = 2)
{
try
{
var parser = new Parser();
var calculator = new CalculatorRPN();
var retValue = Calculate(expr, parser, calculator, precision);
return(Ok(retValue));
}
catch (TokenException ex)
{
// If the expression is formed badly then we won't be able to recover
return(BadRequest(ex.Message));
}
catch (Exception ex)
{
try
{
var parser = new Parser();
var calculator = new CalculatorAPI();
// Try the calculation again by injecting a calculator object to this function that uses the third-party API
var retValue = Calculate(expr, parser, calculator, precision);
return(Ok(retValue));
}
catch (Exception exInner)
{
return(BadRequest(exInner.Message));
}
}
}
[TestCase(-2, CalcOperatorType.Division, 3, 2, -0.67)] // 1 / 6
public void Precision(double op1, CalcOperatorType calcType, double op2, int precision, double expected)
{
var sut = new CalculatorRPN();
sut.AddNumber(op1);
sut.AddOperator(new CalcOperator(calcType));
sut.AddNumber(op2);
Assert.AreEqual(expected, sut.Value(precision));
}
[TestCase(6, CalcOperatorType.Division, 0.5, 12)] // 6 / 0.5
public void TwoOperands(double op1, CalcOperatorType calcType, double op2, double expected)
{
var sut = new CalculatorRPN();
sut.AddNumber(op1);
sut.AddOperator(new CalcOperator(calcType));
sut.AddNumber(op2);
Assert.AreEqual(expected, sut.Value());
}
[TestCase(3, CalcOperatorType.Addition)] // 3 +
public void SingleOperandException(double op1, CalcOperatorType calcType)
{
var sut = new CalculatorRPN();
sut.AddNumber(op1);
sut.AddOperator(new CalcOperator(calcType));
double x;
var ex = Assert.Throws <TokenException>(() => x = sut.Value());
Assert.AreEqual("Not enough values to perform operation.", ex.Message);
}
[TestCase(3, CalcOperatorType.Addition, 2, 1)] // 3 + 2 1
public void TooManyOperandException(double op1, CalcOperatorType calcType, double op2, double op3)
{
var sut = new CalculatorRPN();
sut.AddNumber(op1);
sut.AddOperator(new CalcOperator(calcType));
sut.AddNumber(op2);
sut.AddNumber(op3);
double x;
var ex = Assert.Throws <TokenException>(() => x = sut.Value());
Assert.AreEqual("Too many remaining operands.", ex.Message);
}
