public void Calculator(string hasChanged)
{
try
{
//Sees if user wants to calculate from base value or quote value.
//Checks if the values in the textboxes are correct for calling the calculate method.
if ("BaseValue" == hasChanged && BaseValue != "." && BaseValue != "")
{
QuoteValue = CurrenciesCalculator.CalculateQuoteValue(BaseValue, Rate).
ToString(CultureInfo.GetCultureInfo("en-US"));
}
else if ("QuoteValue" == hasChanged && QuoteValue != "." && QuoteValue != "")
{
BaseValue = CurrenciesCalculator.CalculateBaseValue(QuoteValue, Rate).
ToString(CultureInfo.GetCultureInfo("en-US"));
}
//If not, it clears them.
else
{
BaseValue = "";
QuoteValue = "";
}
}
catch (OverflowException)
{
MessageBox.Show("The input value is out of the accepted range.", "Error");
BaseValue = "";
QuoteValue = "";
}
catch (FormatException)
{
MessageBox.Show($"The input value is invalid. Use only digits or point \".\" as decimal separator. "
+ $"For example: 15.34 ", "Error");
BaseValue = "";
QuoteValue = "";
}
catch (DivideByZeroException)
{
MessageBox.Show("Couldn't retrieve the requested results (rate = 0).", "Error");
}
catch (Exception)
{
MessageBox.Show("Couldn't retrieve the requested results.", "Error");
}
}
public void CalculateBaseValue_ShouldThrowsFormatExcpetion()
{
Assert.Throws <FormatException>(() => CurrenciesCalculator.CalculateBaseValue("h", 0.3M));
}
public void CalculateBaseValue_ShouldThrowOverflowException()
{
Assert.Throws <OverflowException>(() => CurrenciesCalculator.CalculateBaseValue("999999999999999999999999999", 0.000000000000000000001M));
}
//In case there is some error in the API retrieved values and rate is equal to 0.
public void CalculateBaseValue_ShouldThrowDivideByZeroException()
{
Assert.Throws <DivideByZeroException>(() => CurrenciesCalculator.CalculateBaseValue("12.6", 0));
}
public void CalculateBaseValue_ShouldCalculate(string quoteValue, decimal rate, decimal expected)
{
decimal actual = CurrenciesCalculator.CalculateBaseValue(quoteValue, rate);
Assert.Equal(expected, actual);
}
public void CalculateQuoteValue_ShouldThrowFormatException()
{
Assert.Throws <FormatException>(() => CurrenciesCalculator.CalculateQuoteValue("a", 0.5M));
}
