public void ThrowKeyNotFoundExceptionWhenIndexingOnAMissingKey()
{
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
}
};
Assert.Throws <KeyNotFoundException>(() => Console.WriteLine(items[456789]));
// use Contains or TryGetValue to avoid exceptions
Assert.False(items.Contains(456789));
Assert.False(items.TryGetValue(456789, out var item));
}
public void RetrieveValuesByIndexingOnTheirKey()
{
// initializer
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
Assert.Equal("bubble gum", items[123456].Name);
Assert.Equal("popcorn", items[456789].Name);
}
public void RetrieveValuesByIndexingOnTheirIndex()
{
// initializer
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
// cast only necessary because our key is an integer and its indexer is given priority
Assert.Equal("bubble gum", ((IList <StoreItem>)items)[0].Name);
Assert.Equal("popcorn", ((IList <StoreItem>)items)[1].Name);
}
public void NotAllowDuplicateKeysToBeInserted()
{
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
Assert.Throws <ArgumentException>(() => items.Add(new StoreItem {
Upc = 123456, Name = "bubble gum"
}));
// use Contains to avoid exceptions
Assert.True(items.Contains(123456));
}
public void ReplaceValuesByIndexingIntoIList()
{
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
// crazy, but necessary since can't replace by key directly
(items as IList <StoreItem>)[items.IndexOf(items[456789])] = new StoreItem {
Upc = 456789, Name = "potato chips"
};
Assert.Equal("bubble gum", items[123456].Name);
Assert.Equal("potato chips", items[456789].Name);
}
public void RemoveValuesUsingRemoveMethod()
{
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
Assert.True(items.Contains(123456));
Assert.True(items.Contains(456789));
// just remove by key
Assert.True(items.Remove(123456));
// can also remove by specifying the item if available
Assert.False(items.Contains(123456));
Assert.True(items.Contains(456789));
}
public void SupportReadOnlyWrapper()
{
// initializer
var dictionary = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
// wrapped in ReadOnlyDictionary<TKey,TValue> which doesn't allow access to underlying dictionary
var readOnlyCollection = new ReadOnlyCollection <StoreItem>(dictionary);
// IDictionary implemented explicitly -> nave to cast to use
Assert.Equal(2, readOnlyCollection.Count);
Assert.Throws <NotSupportedException>(() => (readOnlyCollection as IList <StoreItem>).Add(new StoreItem {
Upc = 987654, Name = "blah"
}));
Assert.Throws <NotSupportedException>(() => (readOnlyCollection as IList <StoreItem>)[987654] = new StoreItem {
Upc = 987654, Name = "blah"
});
Assert.Throws <NotSupportedException>(() => (readOnlyCollection as IList <StoreItem>).RemoveAt(0));
Assert.Equal(2, readOnlyCollection.Count);
// original list modifications reflected in read-only version
dictionary.Add(new StoreItem {
Upc = 24680, Name = "some new item"
});
dictionary.Add(new StoreItem {
Upc = 13457, Name = "some other item"
});
Assert.Equal(4, readOnlyCollection.Count);
}
public void ImplementIEnumerableOfItems()
{
var items = new StoreItemsByUpcDictionary
{
new StoreItem {
Upc = 123456, Name = "bubble gum"
},
new StoreItem {
Upc = 456789, Name = "popcorn"
}
};
foreach (var item in items)
{
if (item.Upc == 123456)
{
Assert.Equal("bubble gum", item.Name);
}
else
{
Assert.Equal("popcorn", item.Name);
}
}
}
