public void GridList_remove()
{
var list = new GridList <int>();
list.Add(1);
list.Add(5);
list.Add(10);
list.Add(12);
list.Add(15);
list.Add(19);
list.Add(20);
Assert.Equal(7, list.Count);
Assert.True(list.TryErase(12, out var previous));
Assert.NotNull(previous);
Assert.Equal(10, previous.Value);
Assert.False(list.TrySearch(12, out previous));
Assert.Equal(10, previous.Value);
list.TrySearch(5, out var node5);
//deleting 12 again should return false
Assert.False(list.TryErase(12, out previous, node5));
Assert.NotNull(previous);
Assert.Equal(10, previous.Value);
list.Add(7, node5);
Assert.True(list.TrySearch(7, out previous));
//deleting 12 again should return false
Assert.False(list.TryErase(12, out previous, node5));
Assert.NotNull(previous);
Assert.Equal(10, previous.Value);
//remove head
Assert.True(list.TryErase(1, out previous));
Assert.Null(previous);
Assert.False(list.TrySearch(1, out previous));
Assert.Null(previous);//previous is null for first node
Assert.True(list.TrySearch(5, out previous));
Assert.False(list.TrySearch(3, out previous));
Assert.Null(previous);// previous is null if query is before first node
//remove tail
Assert.True(list.TryErase(20, out previous));
Assert.NotNull(previous);
Assert.Equal(19, previous.Value);
Assert.False(list.TrySearch(20, out previous));
Assert.True(list.TrySearch(19, out previous));
Assert.Equal(5, list.Count);
//perform some add after deletion
list.Add(3);
Assert.True(list.TrySearch(3, out previous));
list.Add(21);
Assert.True(list.TrySearch(21, out previous));
Assert.Equal(7, list.Count);
}
