Add a test to verify heuristic is called for each vertex scenario (no…

…rmal, gray, black).
EarthShaping · Jul 25, 2020 · a76b0ed · a76b0ed
1 parent df2f936
commit a76b0ed
Showing 1 changed file with 61 additions and 1 deletion.
diff --git a/tests/QuikGraph.Tests/Algorithms/ShortestPath/AStarShortestPathAlgorithmTests.cs b/tests/QuikGraph.Tests/Algorithms/ShortestPath/AStarShortestPathAlgorithmTests.cs
@@ -361,6 +361,66 @@ public void AStar_Throws()
 
         [Test]
         public void AStar_HeuristicCalls()
+        {
+            var edge01 = new Edge<int>(0, 1);
+            var edge02 = new Edge<int>(0, 2);
+            var edge03 = new Edge<int>(0, 3);
+            var edge14 = new Edge<int>(1, 4);
+            var edge23 = new Edge<int>(2, 3);
+            var edge34 = new Edge<int>(3, 4);
+
+            var graph = new AdjacencyGraph<int, Edge<int>>();
+            graph.AddVerticesAndEdgeRange(new[]
+            {
+                edge01,
+                edge02,
+                edge03,
+                edge23,
+                edge14,
+                edge34
+            });
+
+            const int root = 0;
+
+            var colorUpdates = new HashSet<GraphColor>
+            {
+                GraphColor.White, GraphColor.Gray, GraphColor.Black
+            };
+
+            int heuristicCalls = 0;
+            AStarShortestPathAlgorithm<int, Edge<int>> algorithm = null;
+            Func<int, double> heuristic = v =>
+            {
+                // ReSharper disable once PossibleNullReferenceException
+                // ReSharper disable once AccessToModifiedClosure
+                colorUpdates.Remove(algorithm.GetVertexColor(v));
+                ++heuristicCalls;
+                return 10.0 / heuristicCalls;
+            };
+
+            algorithm = new AStarShortestPathAlgorithm<int, Edge<int>>(
+                graph,
+                e =>
+                {
+                    if (e == edge01)
+                        return 8.0;
+                    if (e == edge02)
+                        return 6.0;
+                    if (e == edge03)
+                        return 20.0;
+                    if (e == edge34)
+                        return 5.0;
+                    return 1.0;
+                },
+                heuristic);
+
+            algorithm.Compute(root);
+
+            CollectionAssert.IsEmpty(colorUpdates);
+        }
+
+        [Test]
+        public void AStar_HeuristicCallCount()
         {
             var lineGraph = new AdjacencyGraph<int, Edge<int>>();
             lineGraph.AddVerticesAndEdgeRange(new[]
@@ -371,7 +431,7 @@ public void AStar_HeuristicCalls()
                 new Edge<int>(1, 0)
             });
 
-            int root = 2;
+            const int root = 2;
 
             var heuristicCalls = new List<int>();
             var algorithm = new AStarShortestPathAlgorithm<int, Edge<int>>(