19 files changed, 143 insertions, 93 deletions

diff --git a/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs b/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs
new file mode 100644
index 00000000..d633c823
--- /dev/null
+++ b/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs
@@ -0,0 +1,25 @@
+// 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.Extensibility.Services
+{
+    /// <summary>
+    /// Abstracts basic file system operations.
+    /// </summary>
+    public interface IFileSystem
+    {
+        /// <summary>
+        /// Copies a file.
+        /// </summary>
+        /// <param name="source">The file to copy.</param>
+        /// <param name="destination">The destination file.</param>
+        /// <param name="allowHardlink">Allow hardlinks.</param>
+        void CopyFile(string source, string destination, bool allowHardlink);
+
+        /// <summary>
+        /// Moves a file.
+        /// </summary>
+        /// <param name="source">The file to move.</param>
+        /// <param name="destination">The destination file.</param>
+        void MoveFile(string source, string destination);
+    }
+}
diff --git a/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs b/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
index 44fb84c7..db4fbf0e 100644
--- a/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bind/BindBundleCommand.cs
@@ -28,6 +28,7 @@ namespace WixToolset.Core.Burn
             this.ServiceProvider = context.ServiceProvider;
 
             this.Messaging = context.ServiceProvider.GetService<IMessaging>();
+            this.FileSystem = context.ServiceProvider.GetService<IFileSystem>();
 
             this.BackendHelper = context.ServiceProvider.GetService<IBackendHelper>();
             this.InternalBurnBackendHelper = context.ServiceProvider.GetService<IInternalBurnBackendHelper>();
@@ -49,6 +50,8 @@ namespace WixToolset.Core.Burn
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IBackendHelper BackendHelper { get; }
 
         private IInternalBurnBackendHelper InternalBurnBackendHelper { get; }
@@ -507,7 +510,7 @@ namespace WixToolset.Core.Burn
             }
 
             {
-                var command = new CreateBundleExeCommand(this.Messaging, this.BackendHelper, this.IntermediateFolder, this.OutputPath, bundleApplicationDllSymbol, bundleSymbol, uxContainer, containers.Values);
+                var command = new CreateBundleExeCommand(this.Messaging, this.FileSystem, this.BackendHelper, this.IntermediateFolder, this.OutputPath, bundleApplicationDllSymbol, bundleSymbol, uxContainer, containers.Values);
                 command.Execute();
 
                 fileTransfers.Add(command.Transfer);
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs b/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs
index e3d0f0af..e87e32c7 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs
@@ -27,16 +27,19 @@ namespace WixToolset.Core.Burn.Bundles
 
         private BinaryReader binaryReader;
         private readonly List<DictionaryEntry> attachedContainerPayloadNames;
+        private readonly IFileSystem fileSystem;
 
         /// <summary>
         /// Creates a BurnReader for reading a PE file.
         /// </summary>
-        /// <param name="messaging"></param>
+        /// <param name="messaging">Messaging.</param>
+        /// <param name="fileSystem">File system.</param>
         /// <param name="fileExe">File to read.</param>
-        private BurnReader(IMessaging messaging, string fileExe)
+        private BurnReader(IMessaging messaging, IFileSystem fileSystem, string fileExe)
             : base(messaging, fileExe)
         {
             this.attachedContainerPayloadNames = new List<DictionaryEntry>();
+            this.fileSystem = fileSystem;
         }
 
         /// <summary>
@@ -47,13 +50,14 @@ namespace WixToolset.Core.Burn.Bundles
         /// <summary>
         /// Opens a Burn reader.
         /// </summary>
-        /// <param name="messaging"></param>
+        /// <param name="messaging">Messaging.</param>
+        /// <param name="fileSystem">File system.</param>
         /// <param name="fileExe">Path to file.</param>
         /// <returns>Burn reader.</returns>
-        public static BurnReader Open(IMessaging messaging, string fileExe)
+        public static BurnReader Open(IMessaging messaging, IFileSystem fileSystem, string fileExe)
         {
             var binaryReader = new BinaryReader(File.Open(fileExe, FileMode.Open, FileAccess.Read, FileShare.Read | FileShare.Delete));
-            var reader = new BurnReader(messaging, fileExe)
+            var reader = new BurnReader(messaging, fileSystem, fileExe)
             {
                 binaryReader = binaryReader,
             };
@@ -96,8 +100,7 @@ namespace WixToolset.Core.Burn.Bundles
             var cabinet = new Cabinet(tempCabPath);
             cabinet.Extract(outputDirectory);
 
-            Directory.CreateDirectory(Path.GetDirectoryName(manifestPath));
-            FileSystem.MoveFile(manifestOriginalPath, manifestPath);
+            this.fileSystem.MoveFile(manifestOriginalPath, manifestPath);
 
             var document = new XmlDocument();
             document.Load(manifestPath);
@@ -114,8 +117,7 @@ namespace WixToolset.Core.Burn.Bundles
                 var sourcePath = Path.Combine(outputDirectory, sourcePathNode.Value);
                 var destinationPath = Path.Combine(outputDirectory, filePathNode.Value);
 
-                Directory.CreateDirectory(Path.GetDirectoryName(destinationPath));
-                FileSystem.MoveFile(sourcePath, destinationPath);
+                this.fileSystem.MoveFile(sourcePath, destinationPath);
             }
 
             foreach (XmlNode payload in payloads)
@@ -183,8 +185,7 @@ namespace WixToolset.Core.Burn.Bundles
                 var sourcePath = Path.Combine(outputDirectory, (string)entry.Key);
                 var destinationPath = Path.Combine(outputDirectory, (string)entry.Value);
 
-                Directory.CreateDirectory(Path.GetDirectoryName(destinationPath));
-                FileSystem.MoveFile(sourcePath, destinationPath);
+                this.fileSystem.MoveFile(sourcePath, destinationPath);
             }
 
             return true;
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs b/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs
index 67a6cb4a..7fe3c4ec 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs
@@ -9,7 +9,6 @@ namespace WixToolset.Core.Burn.Bundles
     using System.Runtime.InteropServices;
     using System.Text;
     using System.Xml;
-    using WixToolset.Core.Native;
     using WixToolset.Data;
     using WixToolset.Data.Burn;
     using WixToolset.Data.Symbols;
@@ -19,9 +18,10 @@ namespace WixToolset.Core.Burn.Bundles
 
     internal class CreateBundleExeCommand
     {
-        public CreateBundleExeCommand(IMessaging messaging, IBackendHelper backendHelper, string intermediateFolder, string outputPath, WixBootstrapperApplicationDllSymbol bootstrapperApplicationDllSymbol, WixBundleSymbol bundleSymbol, WixBundleContainerSymbol uxContainer, IEnumerable<WixBundleContainerSymbol> containers)
+        public CreateBundleExeCommand(IMessaging messaging, IFileSystem fileSystem, IBackendHelper backendHelper, string intermediateFolder, string outputPath, WixBootstrapperApplicationDllSymbol bootstrapperApplicationDllSymbol, WixBundleSymbol bundleSymbol, WixBundleContainerSymbol uxContainer, IEnumerable<WixBundleContainerSymbol> containers)
         {
             this.Messaging = messaging;
+            this.FileSystem = fileSystem;
             this.BackendHelper = backendHelper;
             this.IntermediateFolder = intermediateFolder;
             this.OutputPath = outputPath;
@@ -35,6 +35,8 @@ namespace WixToolset.Core.Burn.Bundles
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IBackendHelper BackendHelper { get; }
 
         private string IntermediateFolder { get; }
@@ -68,7 +70,7 @@ namespace WixToolset.Core.Burn.Bundles
 
             this.Transfer = this.BackendHelper.CreateFileTransfer(bundleTempPath, this.OutputPath, true, this.BundleSymbol.SourceLineNumbers);
 
-            FileSystem.CopyFile(stubFile, bundleTempPath, allowHardlink: false);
+            this.FileSystem.CopyFile(stubFile, bundleTempPath, allowHardlink: false);
             File.SetAttributes(bundleTempPath, FileAttributes.Normal);
 
             var fourPartVersion = this.GetFourPartVersion(this.BundleSymbol);
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/HarvestBundlePackageCommand.cs b/src/wix/WixToolset.Core.Burn/Bundles/HarvestBundlePackageCommand.cs
index 89e0da98..bc065f2f 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/HarvestBundlePackageCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/HarvestBundlePackageCommand.cs
@@ -18,6 +18,7 @@ namespace WixToolset.Core.Burn.Bundles
         public HarvestBundlePackageCommand(IServiceProvider serviceProvider, IEnumerable<IBurnBackendBinderExtension> backendExtensions, string intermediateFolder, WixBundlePayloadSymbol payloadSymbol, WixBundleBundlePackagePayloadSymbol packagePayloadSymbol, Dictionary<string, WixBundlePayloadSymbol> packagePayloadsById)
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
             this.BackendHelper = serviceProvider.GetService<IBackendHelper>();
             this.BackendExtensions = backendExtensions;
             this.IntermediateFolder = intermediateFolder;
@@ -29,6 +30,8 @@ namespace WixToolset.Core.Burn.Bundles
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IBackendHelper BackendHelper { get; }
 
         private IEnumerable<IBurnBackendBinderExtension> BackendExtensions { get; }
@@ -66,7 +69,7 @@ namespace WixToolset.Core.Burn.Bundles
             var sourcePath = this.PackagePayload.SourceFile.Path;
             var sourceLineNumbers = this.PackagePayload.SourceLineNumbers;
 
-            using (var burnReader = BurnReader.Open(this.Messaging, sourcePath))
+            using (var burnReader = BurnReader.Open(this.Messaging, this.FileSystem, sourcePath))
             {
                 if (burnReader.Invalid)
                 {
diff --git a/src/wix/WixToolset.Core.Burn/CommandLine/ExtractSubcommand.cs b/src/wix/WixToolset.Core.Burn/CommandLine/ExtractSubcommand.cs
index 605ee045..5d6edc33 100644
--- a/src/wix/WixToolset.Core.Burn/CommandLine/ExtractSubcommand.cs
+++ b/src/wix/WixToolset.Core.Burn/CommandLine/ExtractSubcommand.cs
@@ -7,21 +7,20 @@ namespace WixToolset.Core.Burn.CommandLine
     using System.Threading;
     using System.Threading.Tasks;
     using WixToolset.Core.Burn.Bundles;
-    using WixToolset.Core.Burn.Inscribe;
     using WixToolset.Extensibility.Services;
 
     internal class ExtractSubcommand : BurnSubcommandBase
     {
         public ExtractSubcommand(IServiceProvider serviceProvider)
         {
-            this.ServiceProvider = serviceProvider;
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
         }
 
-        private IServiceProvider ServiceProvider { get; }
-
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private string InputPath { get; set; }
 
         private string IntermediateFolder { get; set; }
@@ -49,7 +48,7 @@ namespace WixToolset.Core.Burn.CommandLine
 
             var uxExtractPath = Path.Combine(this.ExtractPath, "BA");
 
-            using (var reader = BurnReader.Open(this.Messaging, this.InputPath))
+            using (var reader = BurnReader.Open(this.Messaging, this.FileSystem, this.InputPath))
             {
                 reader.ExtractUXContainer(uxExtractPath, this.IntermediateFolder);
 
diff --git a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs
index 6e071fe7..d68d372c 100644
--- a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Core.Burn.Inscribe
     using System;
     using System.IO;
     using WixToolset.Core.Burn.Bundles;
-    using WixToolset.Core.Native;
     using WixToolset.Extensibility.Services;
 
     internal class InscribeBundleCommand
@@ -13,6 +12,7 @@ namespace WixToolset.Core.Burn.Inscribe
         public InscribeBundleCommand(IServiceProvider serviceProvider, string inputPath, string signedEngineFile, string outputPath, string intermediateFolder)
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
             this.IntermediateFolder = intermediateFolder;
             this.InputFilePath = inputPath;
             this.SignedEngineFile = signedEngineFile;
@@ -21,6 +21,8 @@ namespace WixToolset.Core.Burn.Inscribe
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private string IntermediateFolder { get; }
 
         private string InputFilePath { get; }
@@ -34,9 +36,9 @@ namespace WixToolset.Core.Burn.Inscribe
             var inscribed = false;
             var tempFile = Path.Combine(this.IntermediateFolder, "~bundle_engine_signed.exe");
 
-            using (var reader = BurnReader.Open(this.Messaging, this.InputFilePath))
+            using (var reader = BurnReader.Open(this.Messaging, this.FileSystem, this.InputFilePath))
             {
-                FileSystem.CopyFile(this.SignedEngineFile, tempFile, allowHardlink: false);
+                this.FileSystem.CopyFile(this.SignedEngineFile, tempFile, allowHardlink: false);
 
                 using (var writer = BurnWriter.Open(this.Messaging, tempFile))
                 {
@@ -44,9 +46,7 @@ namespace WixToolset.Core.Burn.Inscribe
                 }
             }
 
-            Directory.CreateDirectory(Path.GetDirectoryName(this.OutputFile));
-
-            FileSystem.MoveFile(tempFile, this.OutputFile);
+            this.FileSystem.MoveFile(tempFile, this.OutputFile);
 
             return inscribed;
         }
diff --git a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs
index e607a28f..c00788ca 100644
--- a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Core.Burn.Inscribe
     using System;
     using System.IO;
     using WixToolset.Core.Burn.Bundles;
-    using WixToolset.Core.Native;
     using WixToolset.Extensibility.Services;
 
     internal class InscribeBundleEngineCommand
@@ -13,6 +12,7 @@ namespace WixToolset.Core.Burn.Inscribe
         public InscribeBundleEngineCommand(IServiceProvider serviceProvider, string inputPath, string outputPath, string intermediateFolder)
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
             this.IntermediateFolder = intermediateFolder;
             this.InputFilePath = inputPath;
             this.OutputFile = outputPath;
@@ -20,6 +20,8 @@ namespace WixToolset.Core.Burn.Inscribe
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private string IntermediateFolder { get; }
 
         private string InputFilePath { get; }
@@ -30,7 +32,7 @@ namespace WixToolset.Core.Burn.Inscribe
         {
             var tempFile = Path.Combine(this.IntermediateFolder, "bundle_engine_unsigned.exe");
 
-            using (var reader = BurnReader.Open(this.Messaging, this.InputFilePath))
+            using (var reader = BurnReader.Open(this.Messaging, this.FileSystem, this.InputFilePath))
             using (var writer = File.Open(tempFile, FileMode.Create, FileAccess.Write, FileShare.Read | FileShare.Delete))
             {
                 reader.Stream.Seek(0, SeekOrigin.Begin);
@@ -56,9 +58,7 @@ namespace WixToolset.Core.Burn.Inscribe
                 // TODO: update writer with detached container signatures.
             }
 
-            Directory.CreateDirectory(Path.GetDirectoryName(this.OutputFile));
-
-            FileSystem.MoveFile(tempFile, this.OutputFile);
+            this.FileSystem.MoveFile(tempFile, this.OutputFile);
         }
     }
 }
diff --git a/src/wix/WixToolset.Core.Native/DateTimeInterop.cs b/src/wix/WixToolset.Core.Native/DateTimeInterop.cs
index d2a0ba2b..9ab4f813 100644
--- a/src/wix/WixToolset.Core.Native/DateTimeInterop.cs
+++ b/src/wix/WixToolset.Core.Native/DateTimeInterop.cs
@@ -20,8 +20,8 @@ namespace WixToolset.Core.Native
         {
             // dateTime.ToLocalTime() does not match FileTimeToLocalFileTime() for some reason.
             // so we need to call FileTimeToLocalFileTime() from kernel32.dll.
-            long filetime = dateTime.ToFileTime();
-            long localTime = 0;
+            var filetime = dateTime.ToFileTime();
+            var localTime = 0L;
             FileTimeToLocalFileTime(ref filetime, ref localTime);
             FileTimeToDosDateTime(ref localTime, out cabDate, out cabTime);
         }
diff --git a/src/wix/WixToolset.Core.Native/WixToolset.Core.Native.csproj b/src/wix/WixToolset.Core.Native/WixToolset.Core.Native.csproj
index 6553a276..b5c83fba 100644
--- a/src/wix/WixToolset.Core.Native/WixToolset.Core.Native.csproj
+++ b/src/wix/WixToolset.Core.Native/WixToolset.Core.Native.csproj
@@ -24,6 +24,5 @@
 
   <ItemGroup>
     <PackageReference Include="WixToolset.Data" />
-    <PackageReference Include="System.IO.FileSystem.AccessControl" />
   </ItemGroup>
 </Project>
diff --git a/src/wix/WixToolset.Core.TestPackage/BundleExtractor.cs b/src/wix/WixToolset.Core.TestPackage/BundleExtractor.cs
index 3cc98e3a..f8cf49df 100644
--- a/src/wix/WixToolset.Core.TestPackage/BundleExtractor.cs
+++ b/src/wix/WixToolset.Core.TestPackage/BundleExtractor.cs
@@ -39,7 +39,7 @@ namespace WixToolset.Core.TestPackage
         {
             var result = new ExtractBAContainerResult();
             Directory.CreateDirectory(tempFolderPath);
-            using (var burnReader = BurnReader.Open(messaging, bundleFilePath))
+            using (var burnReader = BurnReader.Open(messaging, new TestFileSystem(), bundleFilePath))
             {
                 result.Success = burnReader.ExtractUXContainer(baFolderPath, tempFolderPath);
 
@@ -138,5 +138,20 @@ namespace WixToolset.Core.TestPackage
             document.Load(Path.Combine(baFolderPath, "manifest.xml"));
             return document;
         }
+
+        private class TestFileSystem : IFileSystem
+        {
+            public void CopyFile(string source, string destination, bool allowHardlink)
+            {
+                Directory.CreateDirectory(Path.GetDirectoryName(destination));
+                File.Copy(source, destination);
+            }
+
+            public void MoveFile(string source, string destination)
+            {
+                Directory.CreateDirectory(Path.GetDirectoryName(destination));
+                File.Move(source, destination);
+            }
+        }
     }
 }
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs
index 7af0ca19..7e6a7de0 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs
@@ -71,10 +71,10 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             {
                 merge = MsmInterop.GetMsmMerge();
 
-                FileSystem.ActionWithRetries(() => merge.OpenLog(logPath));
+                ActionWithRetries(() => merge.OpenLog(logPath));
                 logOpen = true;
 
-                FileSystem.ActionWithRetries(() => merge.OpenDatabase(this.OutputPath));
+                ActionWithRetries(() => merge.OpenDatabase(this.OutputPath));
                 databaseOpen = true;
 
                 var featureModulesByMergeId = this.Section.Symbols.OfType<WixFeatureModulesSymbol>().GroupBy(t => t.WixMergeRef).ToDictionary(g => g.Key);
@@ -99,7 +99,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                         }
 
                         this.Messaging.Write(VerboseMessages.OpeningMergeModule(wixMergeRow.SourceFile, mergeLanguage));
-                        FileSystem.ActionWithRetries(() => merge.OpenModule(wixMergeRow.SourceFile, mergeLanguage));
+                        ActionWithRetries(() => merge.OpenModule(wixMergeRow.SourceFile, mergeLanguage));
                         moduleOpen = true;
 
                         trackedFiles.Add(this.BackendHelper.TrackFile(wixMergeRow.SourceFile, TrackedFileType.Input, wixMergeRow.SourceLineNumbers));
@@ -340,5 +340,21 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
             this.TrackedFiles = trackedFiles;
         }
+
+        internal static void ActionWithRetries(Action action, int maxRetries = 3)
+        {
+            for (var attempt = 1; attempt <= maxRetries; ++attempt)
+            {
+                try
+                {
+                    action();
+                    break;
+                }
+                catch when (attempt < maxRetries)
+                {
+                    Thread.Sleep(250);
+                }
+            }
+        }
     }
 }
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/ValidateSubcommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/ValidateSubcommand.cs
index 7d77aa30..eb014086 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/ValidateSubcommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/ValidateSubcommand.cs
@@ -16,10 +16,13 @@ namespace WixToolset.Core.WindowsInstaller.CommandLine
         public ValidateSubcommand(IServiceProvider serviceProvider)
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
         }
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private string DatabasePath { get; set; }
 
         private string WixpdbPath { get; set; }
@@ -76,7 +79,7 @@ namespace WixToolset.Core.WindowsInstaller.CommandLine
                 data = WindowsInstallerData.Load(this.WixpdbPath);
             }
 
-            var command = new ValidateDatabaseCommand(this.Messaging, this.IntermediateFolder, this.DatabasePath, data, this.CubeFiles, this.Ices, this.SuppressIces);
+            var command = new ValidateDatabaseCommand(this.Messaging, this.FileSystem, this.IntermediateFolder, this.DatabasePath, data, this.CubeFiles, this.Ices, this.SuppressIces);
             command.Execute();
 
             return Task.FromResult(this.Messaging.EncounteredError ? 1 : 0);
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs
index fa01a119..06fa6817 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs
@@ -18,9 +18,10 @@ namespace WixToolset.Core.WindowsInstaller.Validate
         // Set of ICEs that have equivalent-or-better checks in WiX.
         private static readonly string[] WellKnownSuppressedIces = new[] { "ICE08", "ICE33", "ICE47", "ICE66" };
 
-        public ValidateDatabaseCommand(IMessaging messaging, string intermediateFolder, string databasePath, WindowsInstallerData data, IEnumerable<string> cubeFiles, IEnumerable<string> ices, IEnumerable<string> suppressedIces)
+        public ValidateDatabaseCommand(IMessaging messaging, IFileSystem fileSystem, string intermediateFolder, string databasePath, WindowsInstallerData data, IEnumerable<string> cubeFiles, IEnumerable<string> ices, IEnumerable<string> suppressedIces)
         {
             this.Messaging = messaging;
+            this.FileSystem = fileSystem;
             this.Data = data;
             this.DatabasePath = databasePath;
             this.CubeFiles = cubeFiles;
@@ -40,6 +41,8 @@ namespace WixToolset.Core.WindowsInstaller.Validate
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private WindowsInstallerData Data { get; }
 
         private string DatabasePath { get; }
@@ -71,7 +74,7 @@ namespace WixToolset.Core.WindowsInstaller.Validate
             var workingDatabasePath = Path.Combine(this.IntermediateFolder, workingDatabaseFilename);
             try
             {
-                FileSystem.CopyFile(this.DatabasePath, workingDatabasePath, allowHardlink: false);
+                this.FileSystem.CopyFile(this.DatabasePath, workingDatabasePath, allowHardlink: false);
 
                 var attributes = File.GetAttributes(workingDatabasePath);
                 File.SetAttributes(workingDatabasePath, attributes & ~FileAttributes.ReadOnly);
diff --git a/src/wix/WixToolset.Core/Bind/TransferFilesCommand.cs b/src/wix/WixToolset.Core/Bind/TransferFilesCommand.cs
index b3b74fbc..87c2590f 100644
--- a/src/wix/WixToolset.Core/Bind/TransferFilesCommand.cs
+++ b/src/wix/WixToolset.Core/Bind/TransferFilesCommand.cs
@@ -5,7 +5,7 @@ namespace WixToolset.Core.Bind
     using System;
     using System.Collections.Generic;
     using System.IO;
-    using WixToolset.Core.Native;
+    using System.Security.AccessControl;
     using WixToolset.Data;
     using WixToolset.Extensibility;
     using WixToolset.Extensibility.Data;
@@ -13,16 +13,19 @@ namespace WixToolset.Core.Bind
 
     internal class TransferFilesCommand
     {
-        public TransferFilesCommand(IMessaging messaging, IEnumerable<ILayoutExtension> extensions, IEnumerable<IFileTransfer> fileTransfers, bool resetAcls)
+        public TransferFilesCommand(IMessaging messaging, IFileSystem fileSystem, IEnumerable<ILayoutExtension> extensions, IEnumerable<IFileTransfer> fileTransfers, bool resetAcls)
         {
             this.Extensions = extensions;
             this.Messaging = messaging;
+            this.FileSystem = fileSystem;
             this.FileTransfers = fileTransfers;
             this.ResetAcls = resetAcls;
         }
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IEnumerable<ILayoutExtension> Extensions { get; }
 
         private IEnumerable<IFileTransfer> FileTransfers { get; }
@@ -158,7 +161,7 @@ namespace WixToolset.Core.Bind
             {
                 try
                 {
-                    FileSystem.ResetAcls(destinationFiles);
+                    this.AclReset(destinationFiles);
                 }
                 catch (Exception e)
                 {
@@ -177,7 +180,7 @@ namespace WixToolset.Core.Bind
                 }
             }
 
-            FileSystem.CopyFile(source, destination, allowHardlink: true);
+            this.FileSystem.CopyFile(source, destination, allowHardlink: true);
         }
 
         private void MoveFile(string source, string destination)
@@ -190,7 +193,19 @@ namespace WixToolset.Core.Bind
                 }
             }
 
-            FileSystem.MoveFile(source, destination);
+            this.FileSystem.MoveFile(source, destination);
+        }
+
+        private void AclReset(IEnumerable<string> files)
+        {
+            var aclReset = new FileSecurity();
+            aclReset.SetAccessRuleProtection(false, false);
+
+            foreach (var file in files)
+            {
+                var fileInfo = new FileInfo(file);
+                ExtensibilityServices.FileSystem.ActionWithRetries(() => fileInfo.SetAccessControl(aclReset));
+            }
         }
     }
 }
diff --git a/src/wix/WixToolset.Core.Native/FileSystem.cs b/src/wix/WixToolset.Core/ExtensibilityServices/FileSystem.cs
index 3c59c90c..8bda4966 100644
--- a/src/wix/WixToolset.Core.Native/FileSystem.cs
+++ b/src/wix/WixToolset.Core/ExtensibilityServices/FileSystem.cs
@@ -1,26 +1,16 @@
 // 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.Core.Native
+namespace WixToolset.Core.ExtensibilityServices
 {
     using System;
-    using System.Collections.Generic;
     using System.IO;
     using System.Runtime.InteropServices;
-    using System.Security.AccessControl;
     using System.Threading;
+    using WixToolset.Extensibility.Services;
 
-    /// <summary>
-    /// File system helpers.
-    /// </summary>
-    public static class FileSystem
+    internal class FileSystem : IFileSystem
     {
-        /// <summary>
-        /// Copies a file.
-        /// </summary>
-        /// <param name="source">The file to copy.</param>
-        /// <param name="destination">The destination file.</param>
-        /// <param name="allowHardlink">Allow hardlinks.</param>
-        public static void CopyFile(string source, string destination, bool allowHardlink)
+        public void CopyFile(string source, string destination, bool allowHardlink)
         {
             EnsureDirectoryWithoutFile(destination);
 
@@ -41,12 +31,7 @@ namespace WixToolset.Core.Native
             }
         }
 
-        /// <summary>
-        /// Moves a file.
-        /// </summary>
-        /// <param name="source">The file to move.</param>
-        /// <param name="destination">The destination file.</param>
-        public static void MoveFile(string source, string destination)
+        public void MoveFile(string source, string destination)
         {
             EnsureDirectoryWithoutFile(destination);
 
@@ -54,29 +39,13 @@ namespace WixToolset.Core.Native
         }
 
         /// <summary>
-        /// Reset the ACLs on a set of files.
-        /// </summary>
-        /// <param name="files">The list of file paths to set ACLs.</param>
-        public static void ResetAcls(IEnumerable<string> files)
-        {
-            var aclReset = new FileSecurity();
-            aclReset.SetAccessRuleProtection(false, false);
-
-            foreach (var file in files)
-            {
-                var fileInfo = new FileInfo(file);
-                ActionWithRetries(() => fileInfo.SetAccessControl(aclReset));
-            }
-        }
-
-        /// <summary>
         /// Executes an action and retries on any exception up to a few times. Primarily
         /// intended for use with file system operations that might get interrupted by
         /// external systems (usually anti-virus).
         /// </summary>
         /// <param name="action">Action to execute.</param>
         /// <param name="maxRetries">Maximum retry attempts.</param>
-        public static void ActionWithRetries(Action action, int maxRetries = 3)
+        internal static void ActionWithRetries(Action action, int maxRetries = 3)
         {
             for (var attempt = 1; attempt <= maxRetries; ++attempt)
             {
diff --git a/src/wix/WixToolset.Core/LayoutCreator.cs b/src/wix/WixToolset.Core/LayoutCreator.cs
index 7a143680..3e7ecf3a 100644
--- a/src/wix/WixToolset.Core/LayoutCreator.cs
+++ b/src/wix/WixToolset.Core/LayoutCreator.cs
@@ -21,10 +21,13 @@ namespace WixToolset.Core
         internal LayoutCreator(IServiceProvider serviceProvider)
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
         }
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         public void Layout(ILayoutContext context)
         {
             // Pre-layout.
@@ -42,7 +45,7 @@ namespace WixToolset.Core
                 {
                     this.Messaging.Write(VerboseMessages.LayingOutMedia());
 
-                    var command = new TransferFilesCommand(this.Messaging, context.Extensions, context.FileTransfers, context.ResetAcls);
+                    var command = new TransferFilesCommand(this.Messaging, this.FileSystem, context.Extensions, context.FileTransfers, context.ResetAcls);
                     command.Execute();
                 }
 
diff --git a/src/wix/WixToolset.Core/WixToolset.Core.csproj b/src/wix/WixToolset.Core/WixToolset.Core.csproj
index c2551b21..f2ee3a2c 100644
--- a/src/wix/WixToolset.Core/WixToolset.Core.csproj
+++ b/src/wix/WixToolset.Core/WixToolset.Core.csproj
@@ -15,19 +15,12 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\WixToolset.Core.Native\WixToolset.Core.Native.csproj" />
-  </ItemGroup>
-
-  <ItemGroup>
     <PackageReference Include="WixToolset.Data" />
     <PackageReference Include="WixToolset.Extensibility" />
   </ItemGroup>
 
-  <!--
-    These package references are duplicated in WixToolset.Core.TestPackage.csproj. If
-    you update these here, be sure to update them there.
-  -->
   <ItemGroup>
+    <PackageReference Include="System.IO.FileSystem.AccessControl" />
     <PackageReference Include="System.Text.Encoding.CodePages" />
     <PackageReference Include="NuGet.Versioning" />
   </ItemGroup>
diff --git a/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs b/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
index 525b9dd9..fa6b369d 100644
--- a/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
+++ b/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
@@ -27,6 +27,7 @@ namespace WixToolset.Core
             this.AddService((provider, singletons) => AddSingleton<ILayoutServices>(singletons, new LayoutServices(provider)));
             this.AddService((provider, singletons) => AddSingleton<IBackendHelper>(singletons, new BackendHelper(provider)));
             this.AddService((provider, singletons) => AddSingleton<IPathResolver>(singletons, new PathResolver()));
+            this.AddService((provider, singletons) => AddSingleton<IFileSystem>(singletons, new FileSystem()));
             this.AddService((provider, singletons) => AddSingleton<IWixBranding>(singletons, new WixBranding()));
 
             // Transients.