add unit test for multiroute. fix long standing bugs with routing uncovered by said unit test.

ICD.Common.Utils.Tests/RecursionUtilsTest.cs

@@ -26,6 +26,52 @@ namespace ICD.Common.Utils.Tests
 			}
 		}
 
+		private static IEnumerable<int> WideGraph(int node)
+		{
+			switch (node)
+			{
+				case 1:
+					yield return 2;
+					yield return 3;
+					yield return 4;
+					yield return 5;
+					yield return 6;
+					break;
+				case 2:
+					yield return 21;
+					yield return 22;
+					break;
+				case 3:
+					yield return 1;
+					yield return 31;
+					yield return 32;
+					break;
+				case 4:
+					yield return 41;
+					yield return 42;
+					break;
+				case 5:
+					yield return 51;
+					yield return 52;
+					break;
+				case 6:
+					yield return 61;
+					yield return 62;
+					break;
+				case 21:
+					yield return 62;
+					break;
+				case 41:
+					yield return 43;
+					break;
+				case 42:
+					yield return 43;
+					break;
+				default:
+					yield break;
+			}
+		}
+
 		[Test]
 		public void BreadthFirstSearchTest()
 		{
@@ -73,5 +119,61 @@ namespace ICD.Common.Utils.Tests
 			Assert.AreEqual(1, path.Length);
 			Assert.AreEqual(1, path[0]);
 		}
+
+		[Test]
+		public void BreadthFirstSearchManyDestinationsTest()
+		{
+			Assert.Throws<ArgumentNullException>(() => RecursionUtils.BreadthFirstSearchManyDestinations(1, new[] { 1 }, null));
+			Assert.Throws<ArgumentNullException>(() => RecursionUtils.BreadthFirstSearchManyDestinations(1, null, Graph));
+			Assert.IsEmpty(RecursionUtils.BreadthFirstSearchManyDestinations(1, new[] { 5 }, Graph));
+
+			Dictionary<int, IEnumerable<int>> paths = RecursionUtils.BreadthFirstSearchManyDestinations(1, new[] { 21, 22, 31, 43, 62 }, WideGraph);
+
+			//Make sure all paths were found
+			Assert.IsTrue(paths.Keys.Contains(21));
+			Assert.IsTrue(paths.Keys.Contains(22));
+			Assert.IsTrue(paths.Keys.Contains(31));
+			Assert.IsTrue(paths.Keys.Contains(43));
+			Assert.IsTrue(paths.Keys.Contains(62));
+
+			//Make sure the shortest paths are taken
+			Assert.AreEqual(3, paths[21].Count());
+			Assert.AreEqual(3, paths[22].Count());
+			Assert.AreEqual(3, paths[31].Count()); // infinite loop exists between 1 and 3
+			Assert.AreEqual(4, paths[43].Count()); // 43 has two parents of equal distance, 41 and 42
+			Assert.AreEqual(3, paths[62].Count()); // two paths exist, one is 3, one is 4
+
+			// make sure that destinations which were not asked for were not returned
+			Assert.IsFalse(paths.Keys.Contains(1));
+			Assert.IsFalse(paths.Keys.Contains(2));
+			Assert.IsFalse(paths.Keys.Contains(3));
+			Assert.IsFalse(paths.Keys.Contains(32));
+
+			//Verify path for destination 21
+			Assert.AreEqual(1, paths[21].ToArray()[0]);
+			Assert.AreEqual(2, paths[21].ToArray()[1]);
+			Assert.AreEqual(21, paths[21].ToArray()[2]);
+
+			//Verify path for destination 22
+			Assert.AreEqual(1, paths[22].ToArray()[0]);
+			Assert.AreEqual(2, paths[22].ToArray()[1]);
+			Assert.AreEqual(22, paths[22].ToArray()[2]);
+
+			//Verify path for destination 31
+			Assert.AreEqual(1, paths[31].ToArray()[0]);
+			Assert.AreEqual(3, paths[31].ToArray()[1]);
+			Assert.AreEqual(31, paths[31].ToArray()[2]);
+
+			//Verify path for destination 43
+			Assert.AreEqual(1, paths[43].ToArray()[0]);
+			Assert.AreEqual(4, paths[43].ToArray()[1]);
+			Assert.AreEqual(41, paths[43].ToArray()[2]); // when multiple parents exist with valid paths back, the first one should be consistently selected
+			Assert.AreEqual(43, paths[43].ToArray()[3]);
+
+			//Verify path for destination 62
+			Assert.AreEqual(1, paths[62].ToArray()[0]);
+			Assert.AreEqual(6, paths[62].ToArray()[1]);
+			Assert.AreEqual(62, paths[62].ToArray()[2]);
+		}
 	}
 }

ICD.Common.Utils/RecursionUtils.cs

@@ -92,7 +92,7 @@ namespace ICD.Common.Utils
 
 					// Found a path to the destination
 					if (comparer.Equals(node, destination))
-						return GetPath(destination, nodeParents).Reverse();
+						return GetPath(destination, root, nodeParents, comparer).Reverse();
 				}
 			}
 
@@ -166,7 +166,7 @@ namespace ICD.Common.Utils
 							destinationsToBeProcessed.Where(destination => comparer.Equals(closureNode, destination)))
 					{
 						destinationsProcessed.Add(destination);
-						pathsToReturn.Add(destination, GetPath(destination, nodeParents).Reverse());
+						pathsToReturn.Add(destination, GetPath(destination, root, nodeParents, comparer).Reverse().ToArray());
 					}
 
 					foreach (T destination in destinationsProcessed)
@@ -187,15 +187,20 @@ namespace ICD.Common.Utils
 		/// </summary>
 		/// <typeparam name="T"></typeparam>
 		/// <param name="start"></param>
+		/// /// <param name="end"></param>
 		/// <param name="nodeParents"></param>
 		/// <returns></returns>
-		private static IEnumerable<T> GetPath<T>(T start, IDictionary<T, T> nodeParents)
+		private static IEnumerable<T> GetPath<T>(T start, T end, IDictionary<T, T> nodeParents, IEqualityComparer<T> comparer)
 		{
 			IcdHashSet<T> visited = new IcdHashSet<T>();
 
 			while (true)
 			{
 				yield return start;
+
+				if (comparer.Equals(start, end))
+					break;
+
 				visited.Add(start);
 
 				T next;