private GiftCard(Price amount, string code, bool isRedeemed)
{
if (amount.Amount <= 0) throw new ArgumentException("Amount must be greater than 0.", nameof(amount));
Amount = amount;
Code = code;
IsRedeemed = isRedeemed;
}
public Book(string title, string isbn, Price price)
{
if (string.IsNullOrWhiteSpace(title)) throw new ArgumentException("Title must not be empty.", nameof(title));
if (string.IsNullOrWhiteSpace(isbn)) throw new ArgumentException("ISBN must not be empty.", nameof(isbn));
Title = title;
ISBN = isbn;
UpdatePrice(price.Amount, price.Unit);
}
public void CanComparePrices()
{
var a = new Price(1, Currency.EUR);
var b = new Price(1, Currency.EUR);
Assert.IsFalse(a < b);
Assert.IsTrue(a <= b);
Assert.IsTrue(a == b);
Assert.IsFalse(a != b);
Assert.IsTrue(a >= b);
Assert.IsFalse(a > b);
}
public void CanCreatePrice()
{
var x = new Price(1, Currency.EUR);
Assert.IsTrue(x.Amount == 1);
Assert.IsTrue(x.Unit == Currency.EUR);
}
public void CanConvertPrice()
{
var x = new Price(1, Currency.EUR);
Assert.IsTrue(x.ConvertTo(Currency.JPY).Amount > 1);
}
public void CanAddPricesWithDifferentCurrency()
{
var x = new Price(1, Currency.EUR) + new Price(1, Currency.USD);
Assert.IsTrue(x.Unit == Currency.EUR);
Assert.IsTrue(x.Amount > 1);
}
public void CanAddPrices()
{
var x = new Price(1, Currency.EUR) + new Price(1, Currency.EUR);
Assert.IsTrue(x.Unit == Currency.EUR);
Assert.IsTrue(x.Amount == 2);
}
/// <summary>
/// Updates the book's price.
/// </summary>
/// <param name="newPrice">Price must not be negative.</param>
public void UpdatePrice(Price newPrice)
{
if (newPrice.Amount < 0) throw new ArgumentException("Price must not be negative.", nameof(newPrice));
m_price = newPrice;
}
/// <summary>
/// Updates the book's price.
/// </summary>
/// <param name="newPrice">Price must not be negative.</param>
/// <param name="newCurrency">Currency.</param>
public void UpdatePrice(decimal newPrice, Currency currency)
{
if (newPrice < 0) throw new ArgumentException("Price must not be negative.", nameof(newPrice));
m_price = new Price(newPrice, currency);
}
private static bool BinaryOp(Price x, Price y, Func<decimal, decimal, bool> op)
{
if (object.ReferenceEquals(x, null) || object.ReferenceEquals(y, null)) throw new ArgumentNullException();
if (x.Unit == y.Unit) return op(x.Amount, y.Amount);
return op(x.Amount, y.ConvertTo(x.Unit).Amount);
}