public void TestPrependAppend()
{
List <int> list = new List <int>();
var alist = NewList();
List <int>[] lists = new List <int> [13];
SparseAList <int>[] alists = new SparseAList <int>[]
{
NewList(0, 0, out lists[0]),
NewList(2, 1, out lists[1]),
NewList(6, 5, out lists[2]),
NewList(10, 5, out lists[3]),
NewList(15, 11, out lists[4]),
NewList(30, 11, out lists[5]),
NewList(30, 20, out lists[6]),
NewList(60, 20, out lists[7]),
NewList(50, 32, out lists[8]),
NewList(100, 32, out lists[9]),
NewList(80, 53, out lists[10]),
NewList(150, 53, out lists[11]),
NewList(150, 100, out lists[12]),
};
Assert.AreEqual(alists.Length, lists.Length);
// So, let's just do a random series of Append and Prepend operations,
// clearing the list occasionally so that both list sizes vary a lot,
// which will cause the code paths to vary (important because there
// are several different ways these operations can be done).
for (int trial = 0; trial < 20; trial++)
{
if (trial % 4 == 0)
{
alist.Clear();
list.Clear();
}
int whirl = _r.Next(alists.Length);
SparseAList <int> other = alists[whirl];
bool append = _r.Next(2) == 0;
int ric = alist.GetRealItemCount(), otherRic = other.GetRealItemCount(), oldTH = alist.TreeHeight;
if (append)
{
alist.Append(other);
list.AddRange(lists[whirl]);
}
else
{
alist.Prepend(other);
list.InsertRange(0, lists[whirl]);
}
Assert.That(other.GetImmutableCount() == other.Count || other.TreeHeight <= 1);
Assert.That(alist.GetRealItemCount() == ric + otherRic);
Assert.That(alist.GetImmutableCount() >= other.GetImmutableCount() || oldTH == 1);
}
}