public void GetChildAtOrDefault_NullNode_ThrowsArgumentNullException()
{
// Get a valid ITreeWalker.
NodeWalker <int> walker = new NodeWalker <int>();
Assert.Throws <ArgumentNullException>("node", () => walker.GetChildAtOrDefault((Node <int>)null, 0));
Assert.Throws <ArgumentNullException>("nodes", () => walker.GetChildAtOrDefault((Node <int>[])null, 0));
}
public void GetChildAtOrDefault_IndexLessThanZero_ThrowArgumentOutOfRangeException()
{
// Get a valid tree.
var tree =
Node.Create(0).AddChildren(
Node.Create(1));
// Get a valid ITreeWalker.
NodeWalker <int> walker = new NodeWalker <int>();
Assert.Throws <ArgumentOutOfRangeException>("index", () => walker.GetChildAtOrDefault(tree, -1));
Assert.Throws <ArgumentOutOfRangeException>("index", () => walker.GetChildAtOrDefault(EnumerableEx.Return(tree), -1));
}
public void GetChildAtOrDefault_NullTreeWalker_ThrowsArgumentNullException()
{
// Get a valid tree.
var tree =
Node.Create(0).AddChildren(
Node.Create(1));
// Get a null ITreeWalker.
NodeWalker <int> walker = null;
Assert.Throws <ArgumentNullException>("walker", () => walker.GetChildAtOrDefault(tree, 0));
Assert.Throws <ArgumentNullException>("walker", () => walker.GetChildAtOrDefault(EnumerableEx.Return(tree), 0));
}
public void GetChildAtOrDefault_InvalidIndex_ReturnsNull()
{
// Get a valid tree.
var tree =
Node.Create(0).AddChildren(
Node.Create(1));
// Get a valid ITreeWalker.
NodeWalker <int> walker = new NodeWalker <int>();
// Assert.
Assert.Null(walker.GetChildAtOrDefault(tree, 1));
Assert.Equal(
EnumerableEx.Return <Node <int> >(null),
walker.GetChildAtOrDefault(EnumerableEx.Return(tree), 1));
}
public void GetChildAtOrDefault_ValidIndex_ReturnsNode()
{
// Get a valid tree.
var tree =
Node.Create(0).AddChildren(
Node.Create(1));
// Get a valid ITreeWalker.
NodeWalker <int> walker = new NodeWalker <int>();
// Assert.
Assert.Equal(1, walker.GetChildAtOrDefault(tree, 0).Value);
Assert.Equal(
EnumerableEx.Return(1),
walker.GetChildAtOrDefault(EnumerableEx.Return(tree), 0).Select(x => x.Value));
}