public void GraphWithDisconnectedNodes_GetShortestPath_ThrowsArgumentException()
{
GraphNode source = new GraphNode(new Vector2(0f, 0f));
GraphNode destination = new GraphNode(new Vector2(10f, 10f));
Graph disconnectedGraph = new Graph();
disconnectedGraph.AddEdge(
new GraphEdge(source, new GraphNode(new Vector2(1f, 1f)))
);
disconnectedGraph.AddEdge(
new GraphEdge(new GraphNode(new Vector2(5f, 5f)), destination)
);
AStarAlgorithm astar = new AStarAlgorithm(disconnectedGraph);
// Should throw an argument exception, because it cannot
// calculate the shortest path between disconnected nodes.
astar.GetShortestPath(source, destination);
}
public void ConnectedGraph_GetShortestPath_ReturnsCorrectPath()
{
// Create a graph with four nodes, connected in a straight line.
Graph graph = new Graph();
const int NodeCount = 4;
GraphNode start = new GraphNode(new Vector2(0f, 0f));
GraphNode midFirst = new GraphNode(new Vector2(1f, 1f));
GraphNode midSecond = new GraphNode(new Vector2(2f, 2f));
GraphNode destination = new GraphNode(new Vector2(3f, 3f));
graph.AddEdge(new GraphEdge(start, midFirst));
graph.AddEdge(new GraphEdge(midFirst, midSecond));
graph.AddEdge(new GraphEdge(midSecond, destination));
AStarAlgorithm astar = new AStarAlgorithm(graph);
IEnumerable<GraphNode> path =
astar.GetShortestPath(start, destination).Path;
Assert.IsTrue(path.Count() == NodeCount,
"Path has an invalid amount of nodes");
}