1 files changed, 93 insertions, 0 deletions

diff --git a/src/tools/heat/Mutator.cs b/src/tools/heat/Mutator.cs
new file mode 100644
index 00000000..8c63882d
--- /dev/null
+++ b/src/tools/heat/Mutator.cs
@@ -0,0 +1,93 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Harvesters
+{
+    using System;
+    using System.Collections;
+    using WixToolset.Harvesters.Extensibility;
+    using Wix = WixToolset.Harvesters.Serialize;
+
+    /// <summary>
+    /// The WiX Toolset mutator.
+    /// </summary>
+    internal class Mutator : IMutator
+    {
+        private SortedList extensions;
+        private string extensionArgument;
+
+        /// <summary>
+        /// Instantiate a new mutator.
+        /// </summary>
+        public Mutator()
+        {
+            this.extensions = new SortedList();
+        }
+
+        public IHarvesterCore Core { get; set; }
+
+        public string ExtensionArgument
+        {
+            get { return this.extensionArgument; }
+            set { this.extensionArgument = value; }
+        }
+
+        public void AddExtension(IMutatorExtension mutatorExtension)
+        {
+            this.extensions.Add(mutatorExtension.Sequence, mutatorExtension);
+        }
+
+        public bool Mutate(Wix.Wix wix)
+        {
+            bool encounteredError = false;
+            
+            try
+            {
+                foreach (IMutatorExtension mutatorExtension in this.extensions.Values)
+                {
+                    if (null == mutatorExtension.Core)
+                    {
+                        mutatorExtension.Core = this.Core;
+                    }
+
+                    mutatorExtension.Mutate(wix);
+                }
+            }
+            finally
+            {
+                encounteredError = this.Core.Messaging.EncounteredError;
+            }
+
+            // return the Wix document element only if mutation completed successfully
+            return !encounteredError;
+        }
+
+        public string Mutate(string wixString)
+        {
+            bool encounteredError = false;
+
+            try
+            {
+                foreach (IMutatorExtension mutatorExtension in this.extensions.Values)
+                {
+                    if (null == mutatorExtension.Core)
+                    {
+                        mutatorExtension.Core = this.Core;
+                    }
+
+                    wixString = mutatorExtension.Mutate(wixString);
+
+                    if (String.IsNullOrEmpty(wixString) || this.Core.Messaging.EncounteredError)
+                    {
+                        break;
+                    }
+                }
+            }
+            finally
+            {
+                encounteredError = this.Core.Messaging.EncounteredError;
+            }
+
+            return encounteredError ? null : wixString;
+        }
+    }
+}