public void GeometryGraphBreathFirstEnumeratorMoveNextTest()
{
// empty graph
GeometryGraph graph = new GeometryGraph(PrecisionModel.Default, null, null);
IEnumerator <IGraphVertex> enumerator = graph.GetEnumerator(EnumerationStrategy.BreathFirst);
Assert.IsNull(enumerator.Current);
Assert.IsFalse(enumerator.MoveNext());
Assert.IsNull(enumerator.Current);
// weekly connected graph
graph = new GeometryGraph(PrecisionModel.Default, null, null);
IGraphVertex v1 = graph.AddVertex(new Coordinate(10, 10));
IGraphVertex v2 = graph.AddVertex(new Coordinate(0, 0));
graph.AddEdge(v1, v2);
enumerator = graph.GetEnumerator(EnumerationStrategy.BreathFirst);
List <IGraphVertex> list = new List <IGraphVertex>();
while (enumerator.MoveNext())
{
list.Add(enumerator.Current);
}
Assert.AreEqual(list.Count, graph.VertexCount);
Assert.IsTrue(list.All(vertex => graph.Vertices.Contains(vertex)));
// strongly connected graph
graph = new GeometryGraph(PrecisionModel.Default, null, null);
v1 = graph.AddVertex(new Coordinate(10, 10));
v2 = graph.AddVertex(new Coordinate(0, 0));
graph.AddEdge(v1, v2);
graph.AddEdge(v2, v1);
enumerator = graph.GetEnumerator(EnumerationStrategy.BreathFirst);
list = new List <IGraphVertex>();
while (enumerator.MoveNext())
{
list.Add(enumerator.Current);
}
Assert.AreEqual(list.Count, graph.VertexCount);
Assert.IsTrue(list.All(vertex => graph.Vertices.Contains(vertex)));
// disconnected graph
graph = new GeometryGraph(PrecisionModel.Default, null, null);
v1 = graph.AddVertex(new Coordinate(10, 10));
v2 = graph.AddVertex(new Coordinate(0, 0));
IGraphVertex v3 = graph.AddVertex(new Coordinate(5, 5));
IGraphVertex v4 = graph.AddVertex(new Coordinate(15, 15));
graph.AddEdge(v1, v2);
graph.AddEdge(v2, v1);
graph.AddEdge(v3, v4);
enumerator = graph.GetEnumerator(EnumerationStrategy.BreathFirst);
list = new List <IGraphVertex>();
while (enumerator.MoveNext())
{
list.Add(enumerator.Current);
}
Assert.AreEqual(list.Count, graph.VertexCount);
Assert.IsTrue(list.All(vertex => graph.Vertices.Contains(vertex)));
// modified collection
graph.AddVertex(new Coordinate(20, 20));
Assert.Throws <InvalidOperationException>(() => enumerator.MoveNext());
}