public void CardEquality()
{
var card1 = new Card_IsMutable_Correct(CardValue.Two, CardSuit.Club);
var card2 = new Card_IsMutable_Correct(CardValue.Two, CardSuit.Club);
Assert.Equal(card1, card2);
}
public void Card_IsMutable_CausesProblems_OnHashTable()
{
var mutableCard = new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond);
//add the Ace Of Diamonds to the hash table
var hash = new HashSet <Card_IsMutable_Correct>();
hash.Add(mutableCard);
Assert.Equal(mutableCard, new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond));
Assert.True(hash.Contains(new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond)));
//now we mutate the mutableCard from an Ace Of Diamonds to an Ace Of Hearts
mutableCard.Suit = CardSuit.Heart;
//the mutated card is equal to an Ace of Hearts
Assert.Equal(mutableCard, new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Heart));
Assert.True(hash.Contains(new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Heart)));
var i = hash.GetEnumerator();
i.MoveNext();
var cardFromHashTable = i.Current;
Assert.Equal(cardFromHashTable, new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Heart));
//now we mutate the mutableCard from an Ace Of Diamonds to an Ace Of Hearts
mutableCard.Suit = CardSuit.Diamond;
Assert.False(hash.Contains(new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Heart)));
Assert.True(hash.Contains(new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond)));
}
public void Card_HashCodes_ShouldBe_Equal()
{
var card1 = new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond);
var card2 = new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond);
Assert.Equal(card1, card2);
Assert.Equal(card1.GetHashCode(), card2.GetHashCode());
}
public void HashTable_Key_MustBe_Unique()
{
var card1 = new Card_IsMutable_Correct(CardValue.Two, CardSuit.Club);
var card2 = new Card_IsMutable_Correct(CardValue.Two, CardSuit.Club);
var hash = new Hashtable();
hash.Add(card1, "");
Assert.Throws <ArgumentException>(() => hash.Add(card2, ""));
}
public void Card_Dictionary_ShouldNotContain_DuplicateKeys()
{
var card1 = new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond);
var card2 = new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond);
var dictionary = new Dictionary <object, string>();
dictionary.Add(card1, "");
Assert.True(dictionary.ContainsKey(card1));
Assert.Throws <ArgumentException>(() =>
dictionary.Add(card2, "")
);
Assert.Single(dictionary);
}
public void Card_IsMutable_CausesProblems()
{
var mutableCard = new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond);
//add the Ace Of Diamonds to the hash table
var hash = new Hashtable();
hash.Add(mutableCard, "");
Assert.Equal(mutableCard, new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond));
Assert.True(hash.ContainsKey(new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Diamond)));
//now we mutate the mutableCard from an Ace Of Diamonds to an Ace Of Hearts
mutableCard.Suit = CardSuit.Heart;
//the mutated card is equal to an Ace of Hearts
Assert.Equal(mutableCard, new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Heart));
//but the Hashtable doesn't contain an ace of hearts
Assert.True(hash.ContainsKey(new Card_IsMutable_Correct(CardValue.Ace, CardSuit.Heart))); //so this fails
}