Adds new graph comparison request handler to the Execution Plan Service. (#1438)

* Adds new graph comparison request handler to the Execution Plan Service.

* Code review changes

* Renames execution plan compare params, result, and request classes.

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/Contracts/ExecutionGraphComparisonResult.cs

@@ -0,0 +1,43 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Collections.Generic;
+
+namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts
+{
+    /// <summary>
+    /// An ExecutionGraphComparisonResult is composed of an execution plan node, but has additional properties
+    /// to keep track of matching ExecutionGraphComparisonResult nodes for execution plan nodes present in the
+    /// the graph being compared against. This class also features a group index that can assist
+    /// with coloring similar sections of execution plans in the UI.
+    /// </summary>
+    public class ExecutionGraphComparisonResult
+    {
+        /// <summary>
+        /// The base ExecutionPlanNode for the ExecutionGraphComparisonResult.
+        /// </summary>
+        public ExecutionPlanNode BaseNode { get; set; }
+        /// <summary>
+        /// The children of the ExecutionGraphComparisonResult.
+        /// </summary>
+        public List<ExecutionGraphComparisonResult> Children { get; set; } = new List<ExecutionGraphComparisonResult>();
+        /// <summary>
+        /// The group index of the ExecutionGraphComparisonResult.
+        /// </summary>
+        public int GroupIndex { get; set; }
+        /// <summary>
+        /// Flag to indicate if the ExecutionGraphComparisonResult has a matching node in the compared execution plan.
+        /// </summary>
+        public bool HasMatch { get; set; }
+        /// <summary>
+        /// List of matching nodes for the ExecutionGraphComparisonResult.
+        /// </summary>
+        public List<ExecutionGraphComparisonResult> MatchingNodes { get; set; } = new List<ExecutionGraphComparisonResult>();
+        /// <summary>
+        /// The parent of the ExecutionGraphComparisonResult.
+        /// </summary>
+        public ExecutionGraphComparisonResult ParentNode { get; set; }
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/Contracts/ExecutionPlanComparisonRequest.cs

@@ -0,0 +1,48 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts
+{
+    public class ExecutionPlanComparisonParams
+    {
+        /// <summary>
+        /// First query execution plan for comparison.
+        /// </summary>
+        public ExecutionPlanGraphInfo FirstExecutionPlanGraphInfo { get; set; }
+
+        /// <summary>
+        /// Second query execution plan for comparison.
+        /// </summary>
+        public ExecutionPlanGraphInfo SecondExecutionPlanGraphInfo { get; set; }
+
+        /// <summary>
+        /// Flag to indicate if the database name should be ignored
+        /// during comparisons.
+        /// </summary>
+        public bool IgnoreDatabaseName { get; set; }
+    }
+
+    public class ExecutionPlanComparisonResult
+    {
+        /// <summary>
+        /// Created ExecutionGraphComparisonResult for the first execution plan
+        /// </summary>
+        public ExecutionGraphComparisonResult FirstComparisonResult { get; set; }
+
+        /// <summary>
+        /// Created ExecutionGraphComparisonResult for the second execution plan
+        /// </summary>
+        public ExecutionGraphComparisonResult SecondComparisonResult { get; set; }
+    }
+
+    public class ExecutionPlanComparisonRequest
+    {
+        public static readonly
+            RequestType<ExecutionPlanComparisonParams, ExecutionPlanComparisonResult> Type =
+                RequestType<ExecutionPlanComparisonParams, ExecutionPlanComparisonResult>.Create("executionPlan/compareExecutionPlanGraph");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/Contracts/ExecutionPlanGraph.cs

@@ -5,7 +5,7 @@
 
 using System.Collections.Generic;
 
-namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
+namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts
 {
     /// <summary>
     /// Execution plan graph object that is sent over JSON RPC
@@ -32,6 +32,10 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
 
     public class ExecutionPlanNode
     {
+        /// <summary>
+        /// ID for the node.
+        /// </summary>
+        public int ID { get; set; }
         /// <summary>
         /// Type of the node. This determines the icon that is displayed for it
         /// </summary>
@@ -146,7 +150,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
         public string QueryWithDescription { get; set; }
     }
 
-    public class ExecutionPlanGraphInfo 
+    public class ExecutionPlanGraphInfo
     {
         /// <summary>
         /// File contents

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/Contracts/GetExecutionPlanRequest.cs

@@ -5,6 +5,7 @@
 
 using System.Collections.Generic;
 using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
 {

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/ExecutionPlanGraphUtils.cs

@@ -10,14 +10,15 @@ using System.Linq;
 using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan;
 using Microsoft.SqlTools.Utility;
 using System.Diagnostics;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
 {
-    public class ShowPlanGraphUtils
+    public class ExecutionPlanGraphUtils
     {
         public static List<ExecutionPlanGraph> CreateShowPlanGraph(string xml, string fileName)
         {
-            ShowPlan.ShowPlanGraph[] graphs = ShowPlan.ShowPlanGraph.ParseShowPlanXML(xml, ShowPlan.ShowPlanType.Unknown);
+            ShowPlanGraph[] graphs = ShowPlanGraph.ParseShowPlanXML(xml, ShowPlan.ShowPlanType.Unknown);
             return graphs.Select(g => new ExecutionPlanGraph
             {
                 Root = ConvertShowPlanTreeToExecutionPlanTree(g.Root),
@@ -31,10 +32,11 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
             }).ToList();
         }
 
-        private static ExecutionPlanNode ConvertShowPlanTreeToExecutionPlanTree(Node currentNode)
+        public static ExecutionPlanNode ConvertShowPlanTreeToExecutionPlanTree(Node currentNode)
         {
             return new ExecutionPlanNode
             {
+                ID = currentNode.ID,
                 Type = currentNode.Operation.Image,
                 Cost = currentNode.Cost,
                 SubTreeCost = currentNode.SubtreeCost,
@@ -49,7 +51,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
             };
         }
 
-        private static ExecutionPlanEdges ConvertShowPlanEdgeToExecutionPlanEdge(Edge edge)
+        public static ExecutionPlanEdges ConvertShowPlanEdgeToExecutionPlanEdge(Edge edge)
         {
             return new ExecutionPlanEdges
             {
@@ -59,7 +61,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
             };
         }
 
-        private static List<ExecutionPlanGraphPropertyBase> GetProperties(PropertyDescriptorCollection props)
+        public static List<ExecutionPlanGraphPropertyBase> GetProperties(PropertyDescriptorCollection props)
         {
             List<ExecutionPlanGraphPropertyBase> propsList = new List<ExecutionPlanGraphPropertyBase>();
             foreach (PropertyValue prop in props)
@@ -96,7 +98,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
             return propsList;
         }
 
-        private static List<ExecutionPlanRecommendation> ParseRecommendations(ShowPlan.ShowPlanGraph g, string fileName)
+        private static List<ExecutionPlanRecommendation> ParseRecommendations(ShowPlanGraph g, string fileName)
         {
             return g.Description.MissingIndices.Select(mi => new ExecutionPlanRecommendation
             {
@@ -148,5 +150,58 @@ GO
                 return String.Empty;
             }
         }
+
+        public static void CopyMatchingNodesIntoSkeletonDTO(ExecutionGraphComparisonResult destRoot, ExecutionGraphComparisonResult srcRoot)
+        {
+            var srcGraphLookupTable = srcRoot.CreateSkeletonLookupTable();
+
+            var queue = new Queue<ExecutionGraphComparisonResult>();
+            queue.Enqueue(destRoot);
+
+            while (queue.Count != 0)
+            {
+                var curNode = queue.Dequeue();
+
+                for (int index = 0; index < curNode.MatchingNodes.Count; ++index)
+                {
+                    var matchingId = curNode.MatchingNodes[index].BaseNode.ID;
+                    var matchingNode = srcGraphLookupTable[matchingId];
+
+                    curNode.MatchingNodes[index] = matchingNode;
+                }
+
+                foreach (var child in curNode.Children)
+                {
+                    queue.Enqueue(child);
+                }
+            }
+        }
+    }
+
+    public static class ExecutionGraphComparisonResultExtensions
+    {
+        public static Dictionary<int, ExecutionGraphComparisonResult> CreateSkeletonLookupTable(this ExecutionGraphComparisonResult node)
+        {
+            var skeletonNodeTable = new Dictionary<int, ExecutionGraphComparisonResult>();
+            var queue = new Queue<ExecutionGraphComparisonResult>();
+            queue.Enqueue(node);
+
+            while (queue.Count != 0)
+            {
+                var curNode = queue.Dequeue();
+
+                if (!skeletonNodeTable.ContainsKey(curNode.BaseNode.ID))
+                {
+                    skeletonNodeTable[curNode.BaseNode.ID] = curNode;
+                }
+
+                foreach (var child in curNode.Children)
+                {
+                    queue.Enqueue(child);
+                }
+            }
+
+            return skeletonNodeTable;
+        }
     }
 }

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/ExecutionPlanService.cs

@@ -6,12 +6,15 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.SqlTools.Hosting.Protocol;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison;
 using Microsoft.SqlTools.ServiceLayer.Hosting;
 
 namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
 {
     /// <summary>
-    /// Main class for Migration Service functionality
+    /// Main class for Execution Plan Service functionality
     /// </summary>
     public sealed class ExecutionPlanService : IDisposable
     {
@@ -20,9 +23,9 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
         private bool disposed;
 
         /// <summary>
-        /// Construct a new MigrationService instance with default parameters
+        /// Construct a new Execution Plan Service instance with default parameters
         /// </summary>
-        public ExecutionPlanService()
+        private ExecutionPlanService()
         {
         }
 
@@ -38,26 +41,23 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
         /// Service host object for sending/receiving requests/events.
         /// Internal for testing purposes.
         /// </summary>
-        internal IProtocolEndpoint ServiceHost
-        {
-            get;
-            set;
-        }
+        internal IProtocolEndpoint ServiceHost { get; set; }
 
         /// <summary>
-        /// Initializes the ShowPlan Service instance
+        /// Initializes the Execution Plan Service instance
         /// </summary>
         public void InitializeService(ServiceHost serviceHost)
         {
-            this.ServiceHost = serviceHost;
-            this.ServiceHost.SetRequestHandler(GetExecutionPlanRequest.Type, HandleGetExecutionPlan);
+            ServiceHost = serviceHost;
+            ServiceHost.SetRequestHandler(GetExecutionPlanRequest.Type, HandleGetExecutionPlan);
+            ServiceHost.SetRequestHandler(ExecutionPlanComparisonRequest.Type, HandleExecutionPlanComparisonRequest);
         }
 
         private async Task HandleGetExecutionPlan(GetExecutionPlanParams requestParams, RequestContext<GetExecutionPlanResult> requestContext)
         {
             try
             {
-                var plans = ShowPlanGraphUtils.CreateShowPlanGraph(requestParams.GraphInfo.GraphFileContent, "");
+                var plans = ExecutionPlanGraphUtils.CreateShowPlanGraph(requestParams.GraphInfo.GraphFileContent, "");
                 await requestContext.SendResult(new GetExecutionPlanResult
                 {
                     Graphs = plans
@@ -70,7 +70,46 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan
         }
 
         /// <summary>
-        /// Disposes the ShowPlan Service
+        /// Handles requests for color matching similar nodes.
+        /// </summary>
+        internal async Task HandleExecutionPlanComparisonRequest(
+            ExecutionPlanComparisonParams requestParams,
+            RequestContext<ExecutionPlanComparisonResult> requestContext)
+        {
+            try
+            {
+                var firstGraphSet = ShowPlanGraph.ParseShowPlanXML(requestParams.FirstExecutionPlanGraphInfo.GraphFileContent, ShowPlanType.Unknown);
+                var firstRootNode = firstGraphSet?[0]?.Root;
+
+                var secondGraphSet = ShowPlanGraph.ParseShowPlanXML(requestParams.SecondExecutionPlanGraphInfo.GraphFileContent, ShowPlanType.Unknown);
+                var secondRootNode = secondGraphSet?[0]?.Root;
+
+                var manager = new SkeletonManager();
+                var firstSkeletonNode = manager.CreateSkeleton(firstRootNode);
+                var secondSkeletonNode = manager.CreateSkeleton(secondRootNode);
+                manager.ColorMatchingSections(firstSkeletonNode, secondSkeletonNode, requestParams.IgnoreDatabaseName);
+
+                var firstGraphComparisonResultDTO = firstSkeletonNode.ConvertToDTO();
+                var secondGraphComparisonResultDTO = secondSkeletonNode.ConvertToDTO();
+                ExecutionPlanGraphUtils.CopyMatchingNodesIntoSkeletonDTO(firstGraphComparisonResultDTO, secondGraphComparisonResultDTO);
+                ExecutionPlanGraphUtils.CopyMatchingNodesIntoSkeletonDTO(secondGraphComparisonResultDTO, firstGraphComparisonResultDTO);
+
+                var result = new ExecutionPlanComparisonResult()
+                {
+                    FirstComparisonResult = firstGraphComparisonResultDTO,
+                    SecondComparisonResult = secondGraphComparisonResultDTO
+                };
+
+                await requestContext.SendResult(result);
+            }
+            catch (Exception e)
+            {
+                await requestContext.SendError(e.ToString());
+            }
+        }
+
+        /// <summary>
+        /// Disposes the Execution Plan Service
         /// </summary>
         public void Dispose()
         {

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/ShowPlan/Comparison/SkeletonManager.cs

@@ -22,7 +22,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
         /// </summary>
         /// <param name="root">Node to construct skeleton of</param>
         /// <returns>SkeletonNode with children representing logical descendants of the input node</returns>
-       public SkeletonNode CreateSkeleton(Node root)
+        public SkeletonNode CreateSkeleton(Node root)
         {
             Node rootNode = root;
             var childCount = root.Children.Count;
@@ -36,7 +36,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
                 }
                 return skeletonParent;
             }
-            else if (childCount == 1) 
+            else if (childCount == 1)
             {
                 if (!ShouldIgnoreDuringComparison(rootNode))
                 {
@@ -63,10 +63,14 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
         public bool AreSkeletonsEquivalent(SkeletonNode root1, SkeletonNode root2, bool ignoreDatabaseName)
         {
             if (root1 == null && root2 == null)
+            {
                 return true;
+            }
 
             if (root1 == null || root2 == null)
+            {
                 return false;
+            }
 
             if (!root1.BaseNode.IsLogicallyEquivalentTo(root2.BaseNode, ignoreDatabaseName))
             {
@@ -80,7 +84,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
             while (childIterator < root1.Children.Count)
             {
                 var checkMatch = AreSkeletonsEquivalent(root1.Children.ElementAt(childIterator), root2.Children.ElementAt(childIterator), ignoreDatabaseName);
-                if (!checkMatch) 
+                if (!checkMatch)
                 {
                     // at least one pair of children (ie inner.Child1 & outer.Child1) didn't match; stop checking rest
                     return false;

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/ShowPlan/Comparison/SkeletonNode.cs

@@ -4,19 +4,21 @@
 //
 
 using System.Collections.Generic;
+using System.Linq;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
 {
     public class SkeletonNode
     {
-        public Node BaseNode {get; set;}
+        public Node BaseNode { get; set; }
         public List<SkeletonNode> MatchingNodes { get; set; }
         public bool HasMatch { get { return MatchingNodes.Count > 0; } }
         public SkeletonNode ParentNode { get; set; }
         public IList<SkeletonNode> Children { get; set; }
 
-        public int GroupIndex 
-        { 
+        public int GroupIndex
+        {
             get
             {
                 return this.BaseNode.GroupIndex;
@@ -54,7 +56,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
             }
         }
 
-        public void AddMatchingSkeletonNode(SkeletonNode match, bool ignoreDatabaseName, bool matchAllChildren=true)
+        public void AddMatchingSkeletonNode(SkeletonNode match, bool ignoreDatabaseName, bool matchAllChildren = true)
         {
             this.BaseNode[NodeBuilderConstants.SkeletonHasMatch] = true;
             if (matchAllChildren == true)
@@ -80,5 +82,43 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison
             return this.BaseNode.Graph;
         }
 
+        public ExecutionGraphComparisonResult ConvertToDTO()
+        {
+            var queue = new Queue<SkeletonNode>();
+            queue.Enqueue(this);
+
+            var skeletonNodeDTO = new ExecutionGraphComparisonResult();
+            var dtoQueue = new Queue<ExecutionGraphComparisonResult>();
+            dtoQueue.Enqueue(skeletonNodeDTO);
+
+            while (queue.Count != 0)
+            {
+                var curNode = queue.Dequeue();
+                var curNodeDTO = dtoQueue.Dequeue();
+
+                curNodeDTO.BaseNode = ExecutionPlanGraphUtils.ConvertShowPlanTreeToExecutionPlanTree(curNode.BaseNode);
+                curNodeDTO.GroupIndex = curNode.GroupIndex;
+                curNodeDTO.HasMatch = curNode.HasMatch;
+                curNodeDTO.MatchingNodes = curNode.MatchingNodes.Select(matchingNode =>
+                {
+                    var skeletonNodeDTO = new Contracts.ExecutionGraphComparisonResult();
+                    skeletonNodeDTO.BaseNode = ExecutionPlanGraphUtils.ConvertShowPlanTreeToExecutionPlanTree(matchingNode.BaseNode);
+
+                    return skeletonNodeDTO;
+                }).ToList();
+
+                foreach (var child in curNode.Children)
+                {
+                    queue.Enqueue(child);
+
+                    var childDTO = new Contracts.ExecutionGraphComparisonResult();
+                    childDTO.ParentNode = curNodeDTO;
+                    curNodeDTO.Children.Add(childDTO);
+                    dtoQueue.Enqueue(childDTO);
+                }
+            }
+
+            return skeletonNodeDTO;
+        }
     }
 }

src/Microsoft.SqlTools.ServiceLayer/ExecutionPlan/ShowPlan/Graph.cs

@@ -7,8 +7,8 @@ namespace Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan
 {
     public class Graph
     {
-        public Node Root;
+        public Node Root { get; set; }
 
-        public Description Description;
+        public Description Description { get; set; }
     }
-}
+}

src/Microsoft.SqlTools.ServiceLayer/HostLoader.cs

@@ -36,6 +36,7 @@ using Microsoft.SqlTools.ServiceLayer.Workspace;
 using Microsoft.SqlTools.ServiceLayer.NotebookConvert;
 using Microsoft.SqlTools.ServiceLayer.ModelManagement;
 using Microsoft.SqlTools.ServiceLayer.TableDesigner;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan;
 
 namespace Microsoft.SqlTools.ServiceLayer
 {
@@ -166,8 +167,8 @@ namespace Microsoft.SqlTools.ServiceLayer
             InitializeHostedServices(serviceProvider, serviceHost);
             serviceHost.ServiceProvider = serviceProvider;
 
-            ExecutionPlan.ExecutionPlanService.Instance.InitializeService(serviceHost);
-            serviceProvider.RegisterSingleService(ExecutionPlan.ExecutionPlanService.Instance);
+            ExecutionPlanService.Instance.InitializeService(serviceHost);
+            serviceProvider.RegisterSingleService(ExecutionPlanService.Instance);
 
             serviceHost.InitializeRequestHandlers();
         }

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/Contracts/ExecuteRequests/ResultSetEvents.cs

@@ -5,7 +5,7 @@
 
 using System.Collections.Generic;
 using Microsoft.SqlTools.Hosting.Protocol.Contracts;
-using Microsoft.SqlTools.ServiceLayer.ExecutionPlan;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.QueryExecution.Contracts.ExecuteRequests
 {

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/QueryExecutionService.cs

@@ -21,6 +21,7 @@ using Microsoft.SqlTools.ServiceLayer.SqlContext;
 using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
 using Microsoft.SqlTools.ServiceLayer.Workspace;
 using Microsoft.SqlTools.Utility;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
 
 namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
 {
@@ -908,7 +909,7 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
                     var xmlString = r.GetRow(0)[0].DisplayValue;
                     try
                     {
-                        plans = ShowPlanGraphUtils.CreateShowPlanGraph(xmlString, Path.GetFileName(ownerUri));
+                        plans = ExecutionPlanGraphUtils.CreateShowPlanGraph(xmlString, Path.GetFileName(ownerUri));
                     }
                     catch (Exception ex)
                     {

test/Microsoft.SqlTools.ServiceLayer.UnitTests/ShowPlan/ShowPlanTests.cs

@@ -9,7 +9,9 @@ using System.IO;
 using System.Reflection;
 using NUnit.Framework;
 using Microsoft.SqlTools.ServiceLayer.ExecutionPlan;
-
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.Contracts;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan;
+using Microsoft.SqlTools.ServiceLayer.ExecutionPlan.ShowPlan.Comparison;
 
 namespace Microsoft.SqlTools.ServiceLayer.UnitTests.ShowPlan
 {
@@ -21,18 +23,265 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.ShowPlan
         public void ParseXMLFileReturnsValidShowPlanGraph()
         {
             ReadFile(".ShowPlan.TestShowPlan.xml");
-            var showPlanGraphs = ShowPlanGraphUtils.CreateShowPlanGraph(queryPlanFileText, "testFile.sql");
+            var showPlanGraphs = ExecutionPlanGraphUtils.CreateShowPlanGraph(queryPlanFileText, "testFile.sql");
             Assert.AreEqual(1, showPlanGraphs.Count, "exactly one show plan graph should be returned");
             Assert.NotNull(showPlanGraphs[0], "graph should not be null");
             Assert.NotNull(showPlanGraphs[0].Root, "graph should have a root");
         }
 
+        [Test]
+        public void CompareShowPlan_CreateSkeleton()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            Assert.NotNull(rootNode, "graph should have a root");
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+
+            Assert.NotNull(skeletonNode, "skeletonNode should not be null");
+        }
+
+        [Test]
+        public void CompareShowPlan_CreateSkeletonUsingDefaultConfiguredNode()
+        {
+            var graph = new ShowPlanGraph()
+            {
+                Root = null,
+                Description = new Description()
+            };
+            var context = new NodeBuilderContext(graph, ShowPlanType.Unknown, null);
+            var node = new Node(default, context);
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(node);
+
+            Assert.NotNull(skeletonNode, "skeletonNode should not be null");
+        }
+
+        [Test]
+        public void CompareShowPlan_DuplicateSkeletons()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+            var skeletonNode2 = skeletonManager.CreateSkeleton(rootNode);
+
+            var skeletonCompareResult = skeletonManager.AreSkeletonsEquivalent(skeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsTrue(skeletonCompareResult);
+        }
+
+        [Test]
+        public void CompareShowPlan_TwoDefaultConfiguredSkeletons()
+        {
+            var graph = new ShowPlanGraph()
+            {
+                Root = null,
+                Description = new Description()
+            };
+            var context = new NodeBuilderContext(graph, ShowPlanType.Unknown, null);
+            var firstRoot = new Node(default, context);
+            var secondRoot = new Node(default, context);
+
+            var skeletonManager = new SkeletonManager();
+            var firstSkeletonNode = skeletonManager.CreateSkeleton(firstRoot);
+            var secondSkeletonNode = skeletonManager.CreateSkeleton(secondRoot);
+
+            var skeletonCompareResult = skeletonManager.AreSkeletonsEquivalent(firstSkeletonNode, secondSkeletonNode, ignoreDatabaseName: true);
+
+            Assert.IsTrue(skeletonCompareResult, "The two compared skeleton nodes should be equivalent");
+        }
+
+        [Test]
+        public void CompareShowPlan_ComparingSkeletonAgainstNull()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+            SkeletonNode skeletonNode2 = null;
+
+            var skeletonCompareResult = skeletonManager.AreSkeletonsEquivalent(skeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsFalse(skeletonCompareResult);
+        }
+
+        [Test]
+        public void CompareShowPlan_DifferentSkeletonChildCount()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+            var skeletonNode2 = skeletonManager.CreateSkeleton(rootNode);
+            skeletonNode2.Children.RemoveAt(skeletonNode2.Children.Count - 1);
+
+            var skeletonCompareResult = skeletonManager.AreSkeletonsEquivalent(skeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsFalse(skeletonCompareResult);
+        }
+
+        [Test]
+        public void CompareShowPlan_ColorMatchingSectionsWithEquivalentSkeletons()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+            var skeletonNode2 = skeletonManager.CreateSkeleton(rootNode);
+
+            Assert.IsFalse(skeletonNode.HasMatch);
+            Assert.IsFalse(skeletonNode2.HasMatch);
+
+            Assert.Zero(skeletonNode.MatchingNodes.Count);
+            Assert.Zero(skeletonNode2.MatchingNodes.Count);
+
+            skeletonManager.ColorMatchingSections(skeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsTrue(skeletonNode.HasMatch);
+            Assert.IsTrue(skeletonNode2.HasMatch);
+
+            Assert.AreEqual(1, skeletonNode.MatchingNodes.Count);
+            Assert.AreEqual(1, skeletonNode2.MatchingNodes.Count);
+        }
+
+        [Test]
+        public void CompareShowPlan_ColorMatchingSectionsWithNullAndNonNullSkeleton()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            SkeletonNode nullSkeletonNode = null;
+            var skeletonNode2 = skeletonManager.CreateSkeleton(rootNode);
+
+            skeletonManager.ColorMatchingSections(nullSkeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsNull(nullSkeletonNode);
+            Assert.IsFalse(skeletonNode2.HasMatch);
+            Assert.Zero(skeletonNode2.MatchingNodes.Count);
+        }
+
+        [Test]
+        public void CompareShowPlan_ColorMatchingSectionsWithTwoNullSKeletons()
+        {
+            var skeletonManager = new SkeletonManager();
+            SkeletonNode skeletonNode = null;
+            SkeletonNode skeletonNode2 = null;
+
+            skeletonManager.ColorMatchingSections(skeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsNull(skeletonNode);
+            Assert.IsNull(skeletonNode2);
+        }
+
+        [Test]
+        public void CompareShowPlan_ColorMatchingSectionsWithNonNullAndNullSkeleton()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+            SkeletonNode nullSkeletonNode = null;
+
+            skeletonManager.ColorMatchingSections(skeletonNode, nullSkeletonNode, ignoreDatabaseName: true);
+
+            Assert.IsFalse(skeletonNode.HasMatch);
+            Assert.Zero(skeletonNode.MatchingNodes.Count);
+            Assert.IsNull(nullSkeletonNode);
+        }
+
+        [Test]
+        public void CompareShowPlan_ColorMatchingSectionsWithDifferentChildCount()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var skeletonNode = skeletonManager.CreateSkeleton(rootNode);
+            var skeletonNode2 = skeletonManager.CreateSkeleton(rootNode);
+            skeletonNode2.Children.RemoveAt(skeletonNode2.Children.Count - 1);
+
+            Assert.IsFalse(skeletonNode.Children[0].HasMatch);
+            Assert.IsFalse(skeletonNode2.Children[0].HasMatch);
+
+            Assert.Zero(skeletonNode.Children[0].MatchingNodes.Count);
+            Assert.Zero(skeletonNode2.Children[0].MatchingNodes.Count);
+
+            skeletonManager.ColorMatchingSections(skeletonNode, skeletonNode2, ignoreDatabaseName: true);
+
+            Assert.IsTrue(skeletonNode.Children[0].HasMatch);
+            Assert.IsTrue(skeletonNode2.Children[0].HasMatch);
+
+            Assert.AreEqual(1, skeletonNode.Children[0].MatchingNodes.Count);
+            Assert.AreEqual(1, skeletonNode2.Children[0].MatchingNodes.Count);
+        }
+
+        [Test]
+        public void CompareShowPlan_FindNextNonIgnoreNode()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            var skeletonManager = new SkeletonManager();
+            var result = skeletonManager.FindNextNonIgnoreNode(rootNode);
+
+            Assert.NotNull(result);
+            Assert.AreEqual("InnerJoin", result.LogicalOpUnlocName);
+        }
+
+        [Test]
+        public void CompareShowPlan_FindNextNonIgnoreNodeWithChildlessRoot()
+        {
+            ReadFile(".ShowPlan.TestShowPlan.xml");
+            var graphs = ShowPlanGraph.ParseShowPlanXML(this.queryPlanFileText, ShowPlanType.Unknown);
+            var rootNode = graphs[0].Root;
+
+            for (int childIndex = 0; childIndex < rootNode.Children.Count; ++childIndex)
+            {
+                rootNode.Children.RemoveAt(0);
+            }
+
+            var skeletonManager = new SkeletonManager();
+            var result = skeletonManager.FindNextNonIgnoreNode(rootNode);
+
+            Assert.IsNull(result);
+        }
+
+        [Test]
+        public void CompareShowPlan_FindNextNonIgnoreNodeWithNullNode()
+        {
+            Node rootNode = null;
+
+            var skeletonManager = new SkeletonManager();
+            var result = skeletonManager.FindNextNonIgnoreNode(rootNode);
+
+            Assert.IsNull(result);
+        }
+
         [Test]
         public void ParsingNestedProperties()
         {
             ReadFile(".ShowPlan.TestShowPlan.xml");
             string[] commonNestedPropertiesNames = { "MemoryGrantInfo", "OptimizerHardwareDependentProperties" };
-            var showPlanGraphs = ShowPlanGraphUtils.CreateShowPlanGraph(queryPlanFileText, "testFile.sql");
+            var showPlanGraphs = ExecutionPlanGraphUtils.CreateShowPlanGraph(queryPlanFileText, "testFile.sql");
             ExecutionPlanNode rootNode = showPlanGraphs[0].Root;
             rootNode.Properties.ForEach(p =>
             {
@@ -49,7 +298,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.ShowPlan
             //The first graph in this execution plan has 3 recommendations
             ReadFile(".ShowPlan.TestShowPlanRecommendations.xml");
             string[] commonNestedPropertiesNames = { "MemoryGrantInfo", "OptimizerHardwareDependentProperties" };
-            var showPlanGraphs = ShowPlanGraphUtils.CreateShowPlanGraph(queryPlanFileText, "testFile.sql");
+            var showPlanGraphs = ExecutionPlanGraphUtils.CreateShowPlanGraph(queryPlanFileText, "testFile.sql");
             List<ExecutionPlanRecommendation> rootNode = showPlanGraphs[0].Recommendations;
             Assert.AreEqual(3, rootNode.Count, "3 recommendations should be returned by the showplan parser");
         }