public void TestKeyComparer_OrderByDescending_WithComparison_NullKeySelector_Throws()
{
Func <int, int> keySelector = null;
Func <int, int, int> keyComparison = Comparer <int> .Default.Compare;
KeyComparer <int> .OrderByDescending <int>(keySelector, keyComparison);
}
public void TestKeyComparer_OrderByDescending_NullKeyComparison_Throws()
{
Func <int, int> keySelector = i => i;
Func <int, int, int> keyComparison = null;
KeyComparer <int> .OrderByDescending <int>(keySelector, keyComparison);
}
public void TestKeyComparer_Descending_SortStringsByLength()
{
Random random = new Random();
string[] names = { "Bob", "George", "Mary", "Jessica", "David" };
IComparer <string> comparer = KeyComparer <string> .OrderByDescending(item => item.Length);
Array.Sort(names, comparer);
string[] expected = { "Jessica", "George", "David", "Mary", "Bob" };
CollectionAssert.AreEqual(expected, names, "The names were not sorted by length.");
}
public void TestKeyComparer_OrderByDescending_WithKeyComparison()
{
// build a week, starting on a Sunday
DateTime firstDate = new DateTime(2013, 1, 6);
DateTime[] week = new DateTime[]
{
new DateTime(2013, 1, 6),
new DateTime(2013, 1, 7),
new DateTime(2013, 1, 8),
new DateTime(2013, 1, 9),
new DateTime(2013, 1, 10),
new DateTime(2013, 1, 11),
new DateTime(2013, 1, 12),
};
// force Mondays to come last!
IComparer <DayOfWeek> dayComparer = NullComparer <DayOfWeek> .Default.ThenBy(day => (DayOfWeek)((int)(day + 6) % 7));
Array.Sort(week, KeyComparer <DateTime> .OrderByDescending(d => d.DayOfWeek, dayComparer.Compare));
Assert.AreEqual(firstDate.AddDays(1), week[week.Length - 1], "Monday did not appear at the end of the week.");
}
public void TestKeyComparer_OrderByDescending_NullKeySelector_Throws()
{
Func <int, int> keySelector = null;
KeyComparer <int> .OrderByDescending <int>(keySelector);
}