public void NonNullKeySelectorComparerThrowsWhenFirstItemIsNullAndSecondItemIsNull()
{
var comparer = new NonNullKeySelectorComparer <KeySelectorTestItem, int>(i => i.Id);
KeySelectorTestItem first = null;
KeySelectorTestItem second = null;
Assert.Throws <ArgumentNullException>(() => comparer.Compare(first, second));
}
public void KeySelectorComparerReturnsZeroWhenFirstItemIsNullAndSecondItemIsNull()
{
var comparer = new KeySelectorComparer <KeySelectorTestItem, int>(i => i.Id);
KeySelectorTestItem first = null;
KeySelectorTestItem second = null;
var result = comparer.Compare(first, second);
Assert.AreEqual(0, result);
}
public void KeySelectorComparerRetunsNegativeOneWhenFirstItemIsNullAndSecondItemIsNot()
{
var comparer = new KeySelectorComparer <KeySelectorTestItem, int>(i => i.Id);
KeySelectorTestItem first = null;
KeySelectorTestItem second = new KeySelectorTestItem {
Id = 1
};
var result = comparer.Compare(first, second);
Assert.AreEqual(-1, result);
}
public void NonNullKeySelectorComparerReturnsZeroWhenFirstKeyIsEqualToSecondKey()
{
var comparer = new NonNullKeySelectorComparer <KeySelectorTestItem, int>(i => i.Id);
var first = new KeySelectorTestItem {
Id = 1
};
var second = new KeySelectorTestItem {
Id = 1
};
var result = comparer.Compare(first, second);
Assert.AreEqual(0, result);
}
public void NonNullKeySelectorComparerReturnsNegativeOneWhenFirstKeyIsLessThanSecondKey()
{
var comparer = new NonNullKeySelectorComparer <KeySelectorTestItem, int>(i => i.Id);
var first = new KeySelectorTestItem {
Id = 1
};
var second = new KeySelectorTestItem {
Id = 2
};
var result = comparer.Compare(first, second);
Assert.AreEqual(-1, result);
}
public void KeySelectorComparerReturnsPositiveOneWhenFirstKeyIsGreaterThanSecondKey()
{
var comparer = new KeySelectorComparer <KeySelectorTestItem, int>(i => i.Id);
var first = new KeySelectorTestItem {
Id = 2
};
var second = new KeySelectorTestItem {
Id = 1
};
var result = comparer.Compare(first, second);
Assert.AreEqual(1, result);
}
