public void ExchangeRate_CanBeExtendedTo_SupportCustomInversions()
{
var stock = new ExchangeRate(CurrencyIsoCode.EUR, CurrencyIsoCode.USD, 1.11111m);
var noOp = new ExtendsInvert(CurrencyIsoCode.EUR, CurrencyIsoCode.USD, 1.11111m);
Assert.That(stock.Invert(), Is.Not.EqualTo(noOp.Invert()));
}
public void Get_ToEURInverse_CorrectRate(CurrencyIsoCode from, decimal rate)
{
ExchangeRate toEuro = _as20110519.Get(from, CurrencyIsoCode.EUR);
ExchangeRate inversed = toEuro.Invert();
Assert.That(inversed.From, Is.EqualTo(CurrencyIsoCode.EUR));
Assert.That(inversed.To, Is.EqualTo(from));
Assert.That(inversed.Rate, Is.EqualTo(rate));
}
public void Invert_SwappedCurrencies_AndInvertedRate()
{
var subject = new ExchangeRate(CurrencyIsoCode.EUR, CurrencyIsoCode.USD, 1.25m);
ExchangeRate inverted = subject.Invert();
Assert.That(inverted.From, Is.EqualTo(CurrencyIsoCode.USD));
Assert.That(inverted.To, Is.EqualTo(CurrencyIsoCode.EUR));
Assert.That(inverted.Rate, Is.EqualTo(0.8m));
}
public void Invert_Switches_The_Currencies()
{
var original = new ExchangeRate(EUR, USD, 1.141233m);
var sut = original.Invert();
sut.From.Should().Be(USD);
sut.To.Should().Be(EUR);
sut.Rate.Should().BeApproximately(0.8762452540366428m, 0.00000001m);
}
public void Get_ToEURInverse_CorrectRate(CurrencyIsoCode from, decimal rate)
{
ExchangeRate toEuro = _as20110519.Get(from, CurrencyIsoCode.EUR);
ExchangeRate inversed = toEuro.Invert();
Assert.That(inversed.From, Is.EqualTo(CurrencyIsoCode.EUR));
Assert.That(inversed.To, Is.EqualTo(from));
Assert.That(inversed.Rate, Is.EqualTo(rate)
.Within(0.00001m), "within 5 decimals due to precision of Invert()");
}
public void Get_FromEURInverse_CorrectRate(CurrencyIsoCode to, decimal rate)
{
ExchangeRate fromEuro = _as20110519.Get(CurrencyIsoCode.EUR, to);
ExchangeRate inversed = fromEuro.Invert();
Assert.That(inversed.From, Is.EqualTo(to));
Assert.That(inversed.To, Is.EqualTo(CurrencyIsoCode.EUR));
Assert.That(inversed.Rate, Is.EqualTo(rate)
.Within(0.00001m), "within 5 decimals error as Invert() uses decimal arithmetic");
}
public void Get_FromEURInverse_CorrectRate(CurrencyIsoCode to, decimal rate)
{
ExchangeRate fromEuro = _as20110519.Get(CurrencyIsoCode.EUR, to);
ExchangeRate inversed = fromEuro.Invert();
Assert.That(inversed.From, Is.EqualTo(to));
Assert.That(inversed.To, Is.EqualTo(CurrencyIsoCode.EUR));
Assert.That(inversed.Rate, Is.EqualTo(rate)
.Within(0.00001),
"for some reason, despite using 5-digits arithmetic 1.13409m is represented as 1.1341m so a error marging is needed");
}
public void Invert_IsPure()
{
var subject = new ExchangeRate(CurrencyIsoCode.EUR, CurrencyIsoCode.USD, 1.25m);
ExchangeRate inverted = subject.Invert();
Assert.That(inverted, Is.Not.SameAs(subject));
Assert.That(subject.From, Is.EqualTo(CurrencyIsoCode.EUR));
Assert.That(subject.To, Is.EqualTo(CurrencyIsoCode.USD));
Assert.That(subject.Rate, Is.EqualTo(1.25m));
}
