private static NTreeNode GenerateTreeWithCycle()
{
NTreeNode tree = GenerateTree();
IEnumerable <NTreeNode> flat = new[] { tree };
for (int i = 0; i < 3; i++)
{
flat = flat.Concat(flat.SelectMany(n => n.Children));
}
flat = flat.Distinct();
NTreeNode loopFrom = flat.SingleOrDefault(n => n.Label == "K");
NTreeNode loopTo = flat.SingleOrDefault(n => n.Label == "B");
loopFrom.Children = new[] { loopTo };
return(tree);
}
public void WhenTraversingLoopingTree_WithCycleHandlingTruncate_FindsCorrectPaths()
{
NTreeNode tree = GenerateTreeWithCycle();
IEnumerable <IEnumerable <string> > paths = TreeTraverser
.GetTraversalPaths(tree, node => node.Children, CyclicGraphBehaviour.Truncate)
.Select(path => path.Select(node => node.Label).ToArray())
.ToArray();
string[][] expected = new[]
{
new[] { "A", "B", "D", "H" },
new[] { "A", "B", "D", "I" },
new[] { "A", "B", "E", "J" },
new[] { "A", "C", "F", "L" },
new[] { "A", "C", "F", "M" },
new[] { "A", "C", "G", "N" },
new[] { "A", "C", "G", "O" },
new[] { "A", "B", "E", "K", "B" }
};
Assert.Equal(expected, paths);
}
public void WhenTraversingSimpleTree_FindsCorrectPaths()
{
NTreeNode tree = GenerateTree();
IEnumerable <IEnumerable <string> > paths = TreeTraverser
.GetTraversalPaths(tree, node => node.Children)
.Select(path => path.Select(node => node.Label).ToArray())
.ToArray();
string[][] expected = new[]
{
new[] { "A", "B", "D", "H" },
new[] { "A", "B", "D", "I" },
new[] { "A", "B", "E", "J" },
new[] { "A", "B", "E", "K" },
new[] { "A", "C", "F", "L" },
new[] { "A", "C", "F", "M" },
new[] { "A", "C", "G", "N" },
new[] { "A", "C", "G", "O" },
};
Assert.Equal(expected, paths);
}
public void WhenTraversingLoopingTree_WithCycleHandlingThrow_ThrowsCyclicGraphException()
{
NTreeNode tree = GenerateTreeWithCycle();
Assert.Throws <CyclicGraphException>(() => TreeTraverser.GetTraversalPaths(tree, node => node.Children, CyclicGraphBehaviour.Throw).ToList());
}