Use file system abstraction to handle retries automatically

Fixes 4791

24 files changed, 143 insertions, 127 deletions

diff --git a/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs b/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs
index 26184462..cd987555 100644
--- a/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs
+++ b/src/api/wix/WixToolset.Extensibility/Services/IFileSystem.cs
@@ -3,6 +3,7 @@
 namespace WixToolset.Extensibility.Services
 {
     using System;
+    using System.IO;
 
     /// <summary>
     /// Abstracts basic file system operations.
@@ -33,6 +34,15 @@ namespace WixToolset.Extensibility.Services
         void MoveFile(string source, string destination);
 
         /// <summary>
+        /// Opens a file.
+        /// </summary>
+        /// <param name="path">The file to open.</param>
+        /// <param name="mode">A System.IO.FileMode value that specifies whether a file is created if one does not exist, and determines whether the contents of existing files are retained or overwritten.</param>
+        /// <param name="access">A System.IO.FileAccess value that specifies the operations that can be performed on the file.</param>
+        /// <param name="share">A System.IO.FileShare value specifying the type of access other threads have to the file.</param>
+        FileStream OpenFile(string path, FileMode mode, FileAccess access, FileShare share);
+
+        /// <summary>
         /// Executes an action and retries on any exception a few times with short pause
         /// between each attempt. Primarily intended for use with file system operations
         /// that might get interrupted by external systems (usually anti-virus).
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs b/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs
index e87e32c7..acc76a3b 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/BurnReader.cs
@@ -56,7 +56,7 @@ namespace WixToolset.Core.Burn.Bundles
         /// <returns>Burn reader.</returns>
         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 binaryReader = new BinaryReader(fileSystem.OpenFile(fileExe, FileMode.Open, FileAccess.Read, FileShare.Read | FileShare.Delete));
             var reader = new BurnReader(messaging, fileSystem, fileExe)
             {
                 binaryReader = binaryReader,
@@ -92,7 +92,7 @@ namespace WixToolset.Core.Burn.Bundles
             var uxContainerSlot = this.AttachedContainers[0];
 
             this.binaryReader.BaseStream.Seek(this.UXAddress, SeekOrigin.Begin);
-            using (Stream tempCab = File.Open(tempCabPath, FileMode.Create, FileAccess.Write))
+            using (Stream tempCab = this.fileSystem.OpenFile(tempCabPath, FileMode.Create, FileAccess.Write, FileShare.Read))
             {
                 BurnCommon.CopyStream(this.binaryReader.BaseStream, tempCab, (int)uxContainerSlot.Size);
             }
@@ -169,7 +169,7 @@ namespace WixToolset.Core.Burn.Bundles
                 var tempCabPath = Path.Combine(tempDirectory, $"a{i}.cab");
 
                 this.binaryReader.BaseStream.Seek(nextAddress, SeekOrigin.Begin);
-                using (Stream tempCab = File.Open(tempCabPath, FileMode.Create, FileAccess.Write))
+                using (Stream tempCab = this.fileSystem.OpenFile(tempCabPath, FileMode.Create, FileAccess.Write, FileShare.Read))
                 {
                     BurnCommon.CopyStream(this.binaryReader.BaseStream, tempCab, (int)cntnr.Size);
                 }
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/BurnWriter.cs b/src/wix/WixToolset.Core.Burn/Bundles/BurnWriter.cs
index 1f0a032e..f6282443 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/BurnWriter.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/BurnWriter.cs
@@ -24,35 +24,33 @@ namespace WixToolset.Core.Burn.Bundles
     {
         private bool disposed;
         private BinaryWriter binaryWriter;
+        private readonly IFileSystem fileSystem;
 
-        /// <summary>
-        /// Creates a BurnWriter for re-writing a PE file.
-        /// </summary>
-        /// <param name="messaging"></param>
-        /// <param name="fileExe">File to modify in-place.</param>
-        private BurnWriter(IMessaging messaging, string fileExe)
+        private BurnWriter(IMessaging messaging, IFileSystem fileSystem, string fileExe)
             : base(messaging, fileExe)
         {
+            this.fileSystem = fileSystem;
         }
 
         /// <summary>
         /// Opens a Burn writer.
         /// </summary>
-        /// <param name="messaging"></param>
+        /// <param name="messaging">Messaging system.</param>
+        /// <param name="fileSystem">File system abstraction.</param>
         /// <param name="fileExe">Path to file.</param>
         /// <returns>Burn writer.</returns>
-        public static BurnWriter Open(IMessaging messaging, string fileExe)
+        public static BurnWriter Open(IMessaging messaging, IFileSystem fileSystem, string fileExe)
         {
-            var writer = new BurnWriter(messaging, fileExe);
+            var writer = new BurnWriter(messaging, fileSystem, fileExe);
 
-            using (var binaryReader = new BinaryReader(File.Open(fileExe, FileMode.Open, FileAccess.Read, FileShare.Read | FileShare.Delete)))
+            using (var binaryReader = new BinaryReader(fileSystem.OpenFile(fileExe, FileMode.Open, FileAccess.Read, FileShare.Read | FileShare.Delete)))
             {
                 writer.Initialize(binaryReader);
             }
 
             if (!writer.Invalid)
             {
-                writer.binaryWriter = new BinaryWriter(File.Open(fileExe, FileMode.Open, FileAccess.ReadWrite, FileShare.Read | FileShare.Delete));
+                writer.binaryWriter = new BinaryWriter(fileSystem.OpenFile(fileExe, FileMode.Open, FileAccess.ReadWrite, FileShare.Read | FileShare.Delete));
             }
 
             return writer;
@@ -109,7 +107,7 @@ namespace WixToolset.Core.Burn.Bundles
         /// <returns>true if the container data is successfully appended; false otherwise</returns>
         public bool AppendContainer(string fileContainer, BurnCommon.Container container)
         {
-            using (var reader = File.OpenRead(fileContainer))
+            using (var reader = this.fileSystem.OpenFile(fileContainer, FileMode.Open, FileAccess.Read, FileShare.Read))
             {
                 return this.AppendContainer(reader, reader.Length, container);
             }
@@ -158,7 +156,7 @@ namespace WixToolset.Core.Burn.Bundles
         public bool AppendContainer(Stream containerStream, long containerSize, BurnCommon.Container container)
         {
             var containerCount = (uint)this.AttachedContainers.Count;
-            uint burnSectionOffsetSize = BURN_SECTION_OFFSET_UXSIZE + (containerCount * sizeof(uint));
+            var burnSectionOffsetSize = BURN_SECTION_OFFSET_UXSIZE + (containerCount * sizeof(uint));
             var containerSlot = new ContainerSlot((uint)containerSize);
 
             switch (container)
diff --git a/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs b/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs
index fdc3dfe3..64e74bbe 100644
--- a/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Bundles/CreateBundleExeCommand.cs
@@ -82,7 +82,7 @@ namespace WixToolset.Core.Burn.Bundles
 
             // Update the .wixburn section to point to at the UX and attached container(s) then attach the containers
             // if they should be attached.
-            using (var writer = BurnWriter.Open(this.Messaging, bundleTempPath))
+            using (var writer = BurnWriter.Open(this.Messaging, this.FileSystem, bundleTempPath))
             {
                 var burnStubFile = new FileInfo(bundleTempPath);
                 writer.InitializeBundleSectionData(burnStubFile.Length, this.BundleSymbol.BundleId);
diff --git a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs
index d68d372c..422ad329 100644
--- a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleCommand.cs
@@ -40,7 +40,7 @@ namespace WixToolset.Core.Burn.Inscribe
             {
                 this.FileSystem.CopyFile(this.SignedEngineFile, tempFile, allowHardlink: false);
 
-                using (var writer = BurnWriter.Open(this.Messaging, tempFile))
+                using (var writer = BurnWriter.Open(this.Messaging, this.FileSystem, tempFile))
                 {
                     inscribed = writer.ReattachContainers(reader);
                 }
diff --git a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs
index c00788ca..3fde859a 100644
--- a/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs
+++ b/src/wix/WixToolset.Core.Burn/Inscribe/InscribeBundleEngineCommand.cs
@@ -33,7 +33,7 @@ namespace WixToolset.Core.Burn.Inscribe
             var tempFile = Path.Combine(this.IntermediateFolder, "bundle_engine_unsigned.exe");
 
             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))
+            using (var writer = this.FileSystem.OpenFile(tempFile, FileMode.Create, FileAccess.Write, FileShare.Read | FileShare.Delete))
             {
                 reader.Stream.Seek(0, SeekOrigin.Begin);
 
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/AssemblyNameReader.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/AssemblyNameReader.cs
index 5dcfa1e6..0bb9c389 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/AssemblyNameReader.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/AssemblyNameReader.cs
@@ -11,14 +11,15 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     using System.Xml;
     using System.Xml.XPath;
     using WixToolset.Data;
+    using WixToolset.Extensibility.Services;
 
     internal static class AssemblyNameReader
     {
-        public static AssemblyName ReadAssembly(SourceLineNumber sourceLineNumbers, string assemblyPath, string fileVersion)
+        public static AssemblyName ReadAssembly(IFileSystem fileSystem, SourceLineNumber sourceLineNumbers, string assemblyPath, string fileVersion)
         {
             try
             {
-                using (var stream = File.OpenRead(assemblyPath))
+                using (var stream = fileSystem.OpenFile(assemblyPath, FileMode.Open, FileAccess.Read, FileShare.Read))
                 using (var peReader = new PEReader(stream))
                 {
                     var reader = peReader.GetMetadataReader();
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
index 41559f8b..e3d70b70 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
@@ -28,15 +28,15 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             this.Messaging = context.ServiceProvider.GetService<IMessaging>();
 
             this.WindowsInstallerBackendHelper = context.ServiceProvider.GetService<IWindowsInstallerBackendHelper>();
-
-            this.PathResolver = this.ServiceProvider.GetService<IPathResolver>();
+            this.FileSystem = context.ServiceProvider.GetService<IFileSystem>();
+            this.PathResolver = context.ServiceProvider.GetService<IPathResolver>();
 
             this.CabbingThreadCount = context.CabbingThreadCount;
             this.CabCachePath = context.CabCachePath;
             this.DefaultCompressionLevel = context.DefaultCompressionLevel;
             this.DelayedFields = context.DelayedFields;
             this.ExpectedEmbeddedFiles = context.ExpectedEmbeddedFiles;
-            this.FileSystemManager = new FileSystemManager(context.FileSystemExtensions);
+            this.FileSystemManager = new FileSystemManager(this.FileSystem, context.FileSystemExtensions);
             this.Intermediate = context.IntermediateRepresentation;
             this.IntermediateFolder = context.IntermediateFolder;
             this.OutputPath = context.OutputPath;
@@ -52,12 +52,14 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             this.BackendExtensions = backendExtension;
         }
 
-        public IServiceProvider ServiceProvider { get; }
+        private IServiceProvider ServiceProvider { get; }
 
         private IMessaging Messaging { get; }
 
         private IWindowsInstallerBackendHelper WindowsInstallerBackendHelper { get; }
 
+        private  IFileSystem FileSystem { get; }
+
         private IPathResolver PathResolver { get; }
 
         private int CabbingThreadCount { get; }
@@ -279,7 +281,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
             // Gather information about files that do not come from merge modules.
             {
-                var command = new UpdateFileFacadesCommand(this.Messaging, section, allFileFacades, fileFacadesFromIntermediate, variableCache, overwriteHash: true);
+                var command = new UpdateFileFacadesCommand(this.Messaging, this.FileSystem, section, allFileFacades, fileFacadesFromIntermediate, variableCache, overwriteHash: true);
                 command.Execute();
             }
 
@@ -323,7 +325,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                     {
                         var updatedFacades = reresolvedFiles.Select(f => allFileFacades.First(ff => ff.Id == f.Id?.Id));
 
-                        var command = new UpdateFileFacadesCommand(this.Messaging, section, allFileFacades, updatedFacades, variableCache, overwriteHash: false);
+                        var command = new UpdateFileFacadesCommand(this.Messaging, this.FileSystem, section, allFileFacades, updatedFacades, variableCache, overwriteHash: false);
                         command.Execute();
                     }
                 }
@@ -461,7 +463,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 var trackMsi = this.WindowsInstallerBackendHelper.TrackFile(this.OutputPath, TrackedFileType.BuiltTargetOutput);
                 trackedFiles.Add(trackMsi);
 
-                var command = new GenerateDatabaseCommand(this.Messaging, this.WindowsInstallerBackendHelper, this.FileSystemManager, data, trackMsi.Path, tableDefinitions, this.IntermediateFolder, keepAddedColumns: false, this.SuppressAddingValidationRows, useSubdirectory: false);
+                var command = new GenerateDatabaseCommand(this.Messaging, this.WindowsInstallerBackendHelper, this.FileSystem, this.FileSystemManager, data, trackMsi.Path, tableDefinitions, this.IntermediateFolder, keepAddedColumns: false, this.SuppressAddingValidationRows, useSubdirectory: false);
                 command.Execute();
 
                 trackedFiles.AddRange(command.GeneratedTemporaryFiles);
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindTransformCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindTransformCommand.cs
index 3d8e7595..e6ab3a28 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindTransformCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindTransformCommand.cs
@@ -13,10 +13,11 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
     internal class BindTransformCommand
     {
-        public BindTransformCommand(IMessaging messaging, IBackendHelper backendHelper, FileSystemManager fileSystemManager, string intermediateFolder, WindowsInstallerData transform, string outputPath, TableDefinitionCollection tableDefinitions)
+        public BindTransformCommand(IMessaging messaging, IBackendHelper backendHelper, IFileSystem fileSystem, FileSystemManager fileSystemManager, string intermediateFolder, WindowsInstallerData transform, string outputPath, TableDefinitionCollection tableDefinitions)
         {
             this.Messaging = messaging;
             this.BackendHelper = backendHelper;
+            this.FileSystem = fileSystem;
             this.FileSystemManager = fileSystemManager;
             this.IntermediateFolder = intermediateFolder;
             this.Transform = transform;
@@ -28,6 +29,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IBackendHelper BackendHelper { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private FileSystemManager FileSystemManager { get; }
 
         private TableDefinitionCollection TableDefinitions { get; }
@@ -398,7 +401,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             {
                 if (!String.IsNullOrEmpty(emptyFile))
                 {
-                    using (var fileStream = File.Create(emptyFile))
+                    using (var fileStream = this.FileSystem.OpenFile(emptyFile, FileMode.Create, FileAccess.Write, FileShare.None))
                     {
                     }
                 }
@@ -434,7 +437,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private void GenerateDatabase(WindowsInstallerData output, string outputPath, bool keepAddedColumns)
         {
-            var command = new GenerateDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystemManager, output, outputPath, this.TableDefinitions, this.IntermediateFolder, keepAddedColumns, suppressAddingValidationRows: true, useSubdirectory: true);
+            var command = new GenerateDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.FileSystemManager, output, outputPath, this.TableDefinitions, this.IntermediateFolder, keepAddedColumns, suppressAddingValidationRows: true, useSubdirectory: true);
             command.Execute();
         }
     }
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/CreatePatchTransformsCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/CreatePatchTransformsCommand.cs
index 0d88cfd1..1f6b6558 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/CreatePatchTransformsCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/CreatePatchTransformsCommand.cs
@@ -16,10 +16,11 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
     internal class CreatePatchTransformsCommand
     {
-        public CreatePatchTransformsCommand(IMessaging messaging, IBackendHelper backendHelper, IPathResolver pathResolver, IFileResolver fileResolver, IReadOnlyCollection<IResolverExtension> resolverExtensions, IReadOnlyCollection<IWindowsInstallerBackendBinderExtension> backendExtensions, Intermediate intermediate, string intermediateFolder, IReadOnlyCollection<IBindPath> bindPaths)
+        public CreatePatchTransformsCommand(IMessaging messaging, IBackendHelper backendHelper, IFileSystem fileSystem, IPathResolver pathResolver, IFileResolver fileResolver, IReadOnlyCollection<IResolverExtension> resolverExtensions, IReadOnlyCollection<IWindowsInstallerBackendBinderExtension> backendExtensions, Intermediate intermediate, string intermediateFolder, IReadOnlyCollection<IBindPath> bindPaths)
         {
             this.Messaging = messaging;
             this.BackendHelper = backendHelper;
+            this.FileSystem = fileSystem;
             this.PathResolver = pathResolver;
             this.FileResolver = fileResolver;
             this.ResolverExtensions = resolverExtensions;
@@ -33,6 +34,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IBackendHelper BackendHelper { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IPathResolver PathResolver { get; }
 
         private IFileResolver FileResolver { get; }
@@ -105,7 +108,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 var exportBasePath = Path.Combine(this.IntermediateFolder, stageFolder);
                 var extractFilesFolder = Path.Combine(exportBasePath, "File");
 
-                var command = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.PathResolver, path, null, OutputType.Product, exportBasePath, extractFilesFolder, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: false);
+                var command = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.PathResolver, path, null, OutputType.Product, exportBasePath, extractFilesFolder, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: false);
                 data = command.Execute();
             }
 
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/FileSystemManager.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/FileSystemManager.cs
index fe65ccef..8707d5f1 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/FileSystemManager.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/FileSystemManager.cs
@@ -5,15 +5,20 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     using System;
     using System.Collections.Generic;
     using System.IO;
+    using System.Runtime.CompilerServices;
     using WixToolset.Extensibility;
+    using WixToolset.Extensibility.Services;
 
     internal class FileSystemManager
     {
-        public FileSystemManager(IEnumerable<IFileSystemExtension> fileSystemExtensions)
+        public FileSystemManager(IFileSystem fileSystem, IEnumerable<IFileSystemExtension> fileSystemExtensions)
         {
+            this.FileSystem = fileSystem;
             this.Extensions = fileSystemExtensions;
         }
 
+        private IFileSystem FileSystem { get; }
+
         private IEnumerable<IFileSystemExtension> Extensions { get; }
 
         public bool CompareFiles(string firstPath, string secondPath)
@@ -27,18 +32,18 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 }
             }
 
-            return BuiltinCompareFiles(firstPath, secondPath);
+            return this.BuiltinCompareFiles(firstPath, secondPath);
         }
 
-        private static bool BuiltinCompareFiles(string firstPath, string secondPath)
+        private bool BuiltinCompareFiles(string firstPath, string secondPath)
         {
             if (String.Equals(firstPath, secondPath, StringComparison.OrdinalIgnoreCase))
             {
                 return true;
             }
 
-            using (var firstStream = File.OpenRead(firstPath))
-            using (var secondStream = File.OpenRead(secondPath))
+            using (var firstStream = this.FileSystem.OpenFile(firstPath, FileMode.Open, FileAccess.Read, FileShare.Read))
+            using (var secondStream = this.FileSystem.OpenFile(secondPath, FileMode.Open, FileAccess.Read, FileShare.Read))
             {
                 if (firstStream.Length != secondStream.Length)
                 {
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/GenerateDatabaseCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/GenerateDatabaseCommand.cs
index b8cca752..361f797d 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/GenerateDatabaseCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/GenerateDatabaseCommand.cs
@@ -18,10 +18,11 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     {
         private const string IdtsSubFolder = "_idts";
 
-        public GenerateDatabaseCommand(IMessaging messaging, IBackendHelper backendHelper, FileSystemManager fileSystemManager, WindowsInstallerData data, string outputPath, TableDefinitionCollection tableDefinitions, string intermediateFolder, bool keepAddedColumns, bool suppressAddingValidationRows, bool useSubdirectory)
+        public GenerateDatabaseCommand(IMessaging messaging, IBackendHelper backendHelper, IFileSystem fileSystem, FileSystemManager fileSystemManager, WindowsInstallerData data, string outputPath, TableDefinitionCollection tableDefinitions, string intermediateFolder, bool keepAddedColumns, bool suppressAddingValidationRows, bool useSubdirectory)
         {
             this.Messaging = messaging;
             this.BackendHelper = backendHelper;
+            this.FileSystem = fileSystem;
             this.FileSystemManager = fileSystemManager;
             this.Data = data;
             this.OutputPath = outputPath;
@@ -34,6 +35,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IBackendHelper BackendHelper { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private FileSystemManager FileSystemManager { get; }
 
         /// <summary>
@@ -358,7 +361,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                         var transformFile = Path.Combine(this.IntermediateFolder, String.Concat(subStorage.Name, ".mst"));
 
                         // Bind the transform.
-                        var command = new BindTransformCommand(this.Messaging, this.BackendHelper, this.FileSystemManager, this.IntermediateFolder, subStorage.Data, transformFile, this.TableDefinitions);
+                        var command = new BindTransformCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.FileSystemManager, this.IntermediateFolder, subStorage.Data, transformFile, this.TableDefinitions);
                         command.Execute();
 
                         if (this.Messaging.EncounteredError)
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/UpdateFileFacadesCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/UpdateFileFacadesCommand.cs
index f2f8e126..7f764f49 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/UpdateFileFacadesCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/UpdateFileFacadesCommand.cs
@@ -19,9 +19,10 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     /// </summary>
     internal class UpdateFileFacadesCommand
     {
-        public UpdateFileFacadesCommand(IMessaging messaging, IntermediateSection section, IEnumerable<IFileFacade> allFileFacades, IEnumerable<IFileFacade> updateFileFacades, IDictionary<string, string> variableCache, bool overwriteHash)
+        public UpdateFileFacadesCommand(IMessaging messaging, IFileSystem fileSystem, IntermediateSection section, IEnumerable<IFileFacade> allFileFacades, IEnumerable<IFileFacade> updateFileFacades, IDictionary<string, string> variableCache, bool overwriteHash)
         {
             this.Messaging = messaging;
+            this.FileSystem = fileSystem;
             this.Section = section;
             this.AllFileFacades = allFileFacades;
             this.UpdateFileFacades = updateFileFacades;
@@ -31,6 +32,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IntermediateSection Section { get; }
 
         private IEnumerable<IFileFacade> AllFileFacades { get; }
@@ -212,7 +215,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 {
                     try
                     {
-                        var assemblyName = AssemblyNameReader.ReadAssembly(facade.SourceLineNumber, fileInfo.FullName, version);
+                        var assemblyName = AssemblyNameReader.ReadAssembly(this.FileSystem, facade.SourceLineNumber, fileInfo.FullName, version);
 
                         this.SetMsiAssemblyName(assemblyNameSymbols, facade, assemblySymbol, "name", assemblyName.Name);
                         this.SetMsiAssemblyName(assemblyNameSymbols, facade, assemblySymbol, "culture", assemblyName.Culture);
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/TransformSubcommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/TransformSubcommand.cs
index e37267bb..3b582e74 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/TransformSubcommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/CommandLine/TransformSubcommand.cs
@@ -21,6 +21,7 @@ namespace WixToolset.Core.WindowsInstaller.CommandLine
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
             this.BackendHelper = serviceProvider.GetService<IBackendHelper>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
             this.PathResolver = serviceProvider.GetService<IPathResolver>();
             this.ExtensionManager = serviceProvider.GetService<IExtensionManager>();
         }
@@ -29,6 +30,8 @@ namespace WixToolset.Core.WindowsInstaller.CommandLine
 
         private IBackendHelper BackendHelper { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IPathResolver PathResolver { get; }
 
         private IExtensionManager ExtensionManager { get; }
@@ -342,11 +345,11 @@ namespace WixToolset.Core.WindowsInstaller.CommandLine
             else
             {
                 var fileSystemExtensions = this.ExtensionManager.GetServices<IFileSystemExtension>();
-                var fileSystemManager = new FileSystemManager(fileSystemExtensions);
+                var fileSystemManager = new FileSystemManager(this.FileSystem, fileSystemExtensions);
 
                 var tableDefinitions = this.GetTableDefinitions();
 
-                var bindCommand = new BindTransformCommand(this.Messaging, this.BackendHelper, fileSystemManager, this.IntermediateFolder, transform, this.OutputPath, tableDefinitions);
+                var bindCommand = new BindTransformCommand(this.Messaging, this.BackendHelper, this.FileSystem, fileSystemManager, this.IntermediateFolder, transform, this.OutputPath, tableDefinitions);
                 bindCommand.Execute();
             }
         }
@@ -379,7 +382,7 @@ namespace WixToolset.Core.WindowsInstaller.CommandLine
         {
             if (!DataLoader.TryLoadWindowsInstallerData(path, out var data))
             {
-                var unbindCommand = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.PathResolver, path, null, OutputType.Product, this.ExportBasePath, null, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: false);
+                var unbindCommand = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.PathResolver, path, null, OutputType.Product, this.ExportBasePath, null, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: false);
                 data = unbindCommand.Execute();
             }
 
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Inscribe/InscribeMsiPackageCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Inscribe/InscribeMsiPackageCommand.cs
index 80fcb8e1..3f0d0c51 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Inscribe/InscribeMsiPackageCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Inscribe/InscribeMsiPackageCommand.cs
@@ -19,6 +19,7 @@ namespace WixToolset.Core.WindowsInstaller.Inscribe
         public InscribeMsiPackageCommand(IServiceProvider serviceProvider, string inputPath, string intermediateFolder, string outputPath)
         {
             this.Messaging = serviceProvider.GetService<IMessaging>();
+            this.FileSystem = serviceProvider.GetService<IFileSystem>();
             this.WindowsInstallerBackendHelper = serviceProvider.GetService<IWindowsInstallerBackendHelper>();
             this.TableDefinitions = new TableDefinitionCollection(WindowsInstallerTableDefinitions.All);
             this.InputPath = inputPath;
@@ -34,6 +35,8 @@ namespace WixToolset.Core.WindowsInstaller.Inscribe
 
         private IMessaging Messaging { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IWindowsInstallerBackendHelper WindowsInstallerBackendHelper { get; }
 
         private TableDefinitionCollection TableDefinitions { get; }
@@ -48,8 +51,7 @@ namespace WixToolset.Core.WindowsInstaller.Inscribe
 
             if (!String.Equals(this.InputPath, this.OutputPath, StringComparison.OrdinalIgnoreCase))
             {
-                Directory.CreateDirectory(Path.GetDirectoryName(this.OutputPath));
-                File.Copy(this.InputPath, this.OutputPath, true);
+                this.FileSystem.CopyFile(this.InputPath, this.OutputPath, allowHardlink: false);
             }
 
             var attributes = File.GetAttributes(databasePath);
@@ -96,7 +98,7 @@ namespace WixToolset.Core.WindowsInstaller.Inscribe
                                 Directory.CreateDirectory(hashPath);
                                 hashPath = Path.Combine(hashPath, hashFileName);
 
-                                using (var fs = File.Create(hashPath))
+                                using (var fs = this.FileSystem.OpenFile(hashPath, FileMode.Create, FileAccess.Write, FileShare.None))
                                 {
                                     int bytesRead;
                                     var buffer = new byte[1024 * 4];
@@ -127,7 +129,7 @@ namespace WixToolset.Core.WindowsInstaller.Inscribe
                             Directory.CreateDirectory(certPath);
                             certPath = Path.Combine(certPath, String.Concat(certificateId, ".cer"));
 
-                            using (var fs = File.Create(certPath))
+                            using (var fs = this.FileSystem.OpenFile(certPath, FileMode.Create, FileAccess.Write, FileShare.None))
                             {
                                 int bytesRead;
                                 var buffer = new byte[1024 * 4];
@@ -221,9 +223,9 @@ namespace WixToolset.Core.WindowsInstaller.Inscribe
                             var certPath = Path.Combine(this.IntermediateFolder, "MsiDigitalCertificate");
                             Directory.CreateDirectory(certPath);
                             certPath = Path.Combine(certPath, String.Concat(cert2.Thumbprint, ".cer"));
-                            File.Delete(certPath);
+                            this.FileSystem.DeleteFile(certPath, true);
 
-                            using (var writer = new BinaryWriter(File.Open(certPath, FileMode.Create)))
+                            using (var writer = new BinaryWriter(this.FileSystem.OpenFile(certPath, FileMode.Create, FileAccess.Write, FileShare.Read)))
                             {
                                 writer.Write(cert2.RawData);
                                 writer.Close();
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/MspBackend.cs b/src/wix/WixToolset.Core.WindowsInstaller/MspBackend.cs
index ace382de..8320bb0a 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/MspBackend.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/MspBackend.cs
@@ -17,6 +17,8 @@ namespace WixToolset.Core.WindowsInstaller
 
             var backendHelper = context.ServiceProvider.GetService<IBackendHelper>();
 
+            var fileSystem = context.ServiceProvider.GetService<IFileSystem>();
+
             var pathResolver = context.ServiceProvider.GetService<IPathResolver>();
 
             var fileResolver = context.ServiceProvider.GetService<IFileResolver>();
@@ -36,7 +38,7 @@ namespace WixToolset.Core.WindowsInstaller
             IEnumerable<PatchTransform> patchTransforms;
             PatchFilterMap patchFilterMap;
             {
-                var command = new CreatePatchTransformsCommand(messaging, backendHelper, pathResolver, fileResolver, resolveExtensions, backendExtensions, context.IntermediateRepresentation, context.IntermediateFolder, context.BindPaths);
+                var command = new CreatePatchTransformsCommand(messaging, backendHelper, fileSystem, pathResolver, fileResolver, resolveExtensions, backendExtensions, context.IntermediateRepresentation, context.IntermediateFolder, context.BindPaths);
                 command.Execute();
 
                 patchTransforms = command.PatchTransforms;
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Unbind/ExtractCabinetsCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Unbind/ExtractCabinetsCommand.cs
index 9aa6f3d4..c2981b08 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Unbind/ExtractCabinetsCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Unbind/ExtractCabinetsCommand.cs
@@ -12,11 +12,13 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
     using WixToolset.Data;
     using WixToolset.Data.WindowsInstaller;
     using WixToolset.Data.WindowsInstaller.Rows;
+    using WixToolset.Extensibility.Services;
 
     internal class ExtractCabinetsCommand
     {
-        public ExtractCabinetsCommand(WindowsInstallerData output, Database database, string inputFilePath, string exportBasePath, string intermediateFolder, bool treatOutputAsModule = false)
+        public ExtractCabinetsCommand(IFileSystem fileSystem, WindowsInstallerData output, Database database, string inputFilePath, string exportBasePath, string intermediateFolder, bool treatOutputAsModule = false)
         {
+            this.FileSystem = fileSystem;
             this.Output = output;
             this.Database = database;
             this.InputFilePath = inputFilePath;
@@ -27,6 +29,8 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
 
         public Dictionary<string, MediaRow> ExtractedFileIdsWithMediaRow { get; private set; }
 
+        private  IFileSystem FileSystem { get; }
+
         private WindowsInstallerData Output { get; }
 
         private Database Database { get; }
@@ -100,7 +104,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
                                 // ensure the parent directory exists
                                 Directory.CreateDirectory(Path.GetDirectoryName(cabinetPath));
 
-                                using (var fs = File.Create(cabinetPath))
+                                using (var fs = this.FileSystem.OpenFile(cabinetPath, FileMode.Create, FileAccess.Write, FileShare.None))
                                 {
                                     int bytesRead;
                                     var buffer = new byte[4096];
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindDatabaseCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindDatabaseCommand.cs
index 7f6537e5..54534e50 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindDatabaseCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindDatabaseCommand.cs
@@ -21,10 +21,11 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
     {
         private static readonly Regex Modularization = new Regex(@"\.[0-9A-Fa-f]{8}_[0-9A-Fa-f]{4}_[0-9A-Fa-f]{4}_[0-9A-Fa-f]{4}_[0-9A-Fa-f]{12}");
 
-        public UnbindDatabaseCommand(IMessaging messaging, IBackendHelper backendHelper, IPathResolver pathResolver, string databasePath, Database database, OutputType outputType, string exportBasePath, string extractFilesFolder, string intermediateFolder, bool enableDemodularization, bool skipSummaryInfo)
+        public UnbindDatabaseCommand(IMessaging messaging, IBackendHelper backendHelper, IFileSystem fileSystem, IPathResolver pathResolver, string databasePath, Database database, OutputType outputType, string exportBasePath, string extractFilesFolder, string intermediateFolder, bool enableDemodularization, bool skipSummaryInfo)
         {
             this.Messaging = messaging;
             this.BackendHelper = backendHelper;
+            this.FileSystem = fileSystem;
             this.PathResolver = pathResolver;
             this.DatabasePath = databasePath;
             this.Database = database;
@@ -38,9 +39,11 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
             this.TableDefinitions = new TableDefinitionCollection(WindowsInstallerTableDefinitions.All);
         }
 
-        public IMessaging Messaging { get; }
+        private IMessaging Messaging { get; }
 
-        public IBackendHelper BackendHelper { get; }
+        private IBackendHelper BackendHelper { get; }
+
+        private  IFileSystem FileSystem { get; }
 
         private IPathResolver PathResolver { get; }
 
@@ -203,7 +206,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
 
                                                     Directory.CreateDirectory(Path.Combine(this.ExportBasePath, tableName));
 
-                                                    using (var fs = File.Create(source))
+                                                    using (var fs = this.FileSystem.OpenFile(source, FileMode.Create, FileAccess.Write, FileShare.None))
                                                     {
                                                         int bytesRead;
                                                         var buffer = new byte[4096];
@@ -531,7 +534,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
 
                 if (!String.IsNullOrEmpty(this.ExtractFilesFolder))
                 {
-                    var extractCommand = new ExtractCabinetsCommand(output, this.Database, this.DatabasePath, this.ExtractFilesFolder, this.IntermediateFolder);
+                    var extractCommand = new ExtractCabinetsCommand(this.FileSystem, output, this.Database, this.DatabasePath, this.ExtractFilesFolder, this.IntermediateFolder);
                     extractCommand.Execute();
 
                     extractedFileIds = new HashSet<string>(extractCommand.ExtractedFileIdsWithMediaRow.Keys, StringComparer.OrdinalIgnoreCase);
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindTransformCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindTransformCommand.cs
index f2567ebb..bb4da1ed 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindTransformCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Unbind/UnbindTransformCommand.cs
@@ -16,10 +16,11 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
 
     internal class UnbindTransformCommand
     {
-        public UnbindTransformCommand(IMessaging messaging, IBackendHelper backendHelper, IPathResolver pathResolver, FileSystemManager fileSystemManager, string transformFile, string exportBasePath, string intermediateFolder)
+        public UnbindTransformCommand(IMessaging messaging, IBackendHelper backendHelper, IFileSystem fileSystem, IPathResolver pathResolver, FileSystemManager fileSystemManager, string transformFile, string exportBasePath, string intermediateFolder)
         {
             this.Messaging = messaging;
             this.BackendHelper = backendHelper;
+            this.FileSystem = fileSystem;
             this.PathResolver = pathResolver;
             this.FileSystemManager = fileSystemManager;
             this.TransformFile = transformFile;
@@ -33,6 +34,8 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
 
         private IBackendHelper BackendHelper { get; }
 
+        private IFileSystem FileSystem { get; }
+
         private IPathResolver PathResolver { get; }
 
         private FileSystemManager FileSystemManager { get; }
@@ -116,7 +119,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
             using (var msiDatabase = this.ApplyTransformToSchemaDatabase(schemaDatabasePath, TransformErrorConditions.All | TransformErrorConditions.ViewTransform))
             {
                 // unbind the database
-                var unbindCommand = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.PathResolver, schemaDatabasePath, msiDatabase, OutputType.Product, null, null, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: true);
+                var unbindCommand = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.PathResolver, schemaDatabasePath, msiDatabase, OutputType.Product, null, null, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: true);
                 var transformViewOutput = unbindCommand.Execute();
 
                 return transformViewOutput.Tables["_TransformView"];
@@ -177,7 +180,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
             {
 
                 // unbind the database
-                var unbindCommand = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.PathResolver, schemaDatabasePath, database, OutputType.Product, this.ExportBasePath, null, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: true);
+                var unbindCommand = new UnbindDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.PathResolver, schemaDatabasePath, database, OutputType.Product, this.ExportBasePath, null, this.IntermediateFolder, enableDemodularization: false, skipSummaryInfo: true);
                 output = unbindCommand.Execute();
             }
 
@@ -324,7 +327,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
                         if (null == this.EmptyFile)
                         {
                             this.EmptyFile = Path.Combine(this.IntermediateFolder, ".empty");
-                            using (var fileStream = File.Create(this.EmptyFile))
+                            using (var fileStream = this.FileSystem.OpenFile(this.EmptyFile, FileMode.Create, FileAccess.Write, FileShare.None))
                             {
                             }
                         }
@@ -343,7 +346,7 @@ namespace WixToolset.Core.WindowsInstaller.Unbind
 
         private void GenerateDatabase(WindowsInstallerData data)
         {
-            var command = new GenerateDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystemManager, data, data.SourceLineNumbers.FileName, this.TableDefinitions, this.IntermediateFolder, keepAddedColumns: true, suppressAddingValidationRows: true, useSubdirectory: false);
+            var command = new GenerateDatabaseCommand(this.Messaging, this.BackendHelper, this.FileSystem, this.FileSystemManager, data, data.SourceLineNumbers.FileName, this.TableDefinitions, this.IntermediateFolder, keepAddedColumns: true, suppressAddingValidationRows: true, useSubdirectory: false);
             command.Execute();
         }
 
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs
index 06fa6817..24dd9927 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Validate/ValidateDatabaseCommand.cs
@@ -34,9 +34,6 @@ namespace WixToolset.Core.WindowsInstaller.Validate
 
         public IEnumerable<ITrackedFile> TrackedFiles { get; private set; }
 
-        /// <summary>
-        /// Encountered error implementation for <see cref="IWindowsInstallerValidatorCallback"/>.
-        /// </summary>
         public bool EncounteredError => this.Messaging.EncounteredError;
 
         private IMessaging Messaging { get; }
@@ -84,10 +81,7 @@ namespace WixToolset.Core.WindowsInstaller.Validate
             }
             finally
             {
-                if (File.Exists(workingDatabasePath))
-                {
-                    File.Delete(workingDatabasePath);
-                }
+                this.FileSystem.DeleteFile(workingDatabasePath);
             }
 
             stopwatch.Stop();
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerDecompiler.cs b/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerDecompiler.cs
index f3d116f6..b41876b3 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerDecompiler.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/WindowsInstallerDecompiler.cs
@@ -3,7 +3,6 @@
 namespace WixToolset.Core.WindowsInstaller
 {
     using System;
-    using System.Collections.Generic;
     using System.IO;
     using System.Linq;
     using WixToolset.Core.WindowsInstaller.Bind;
@@ -74,25 +73,27 @@ namespace WixToolset.Core.WindowsInstaller
 
             var backendHelper = context.ServiceProvider.GetService<IWindowsInstallerBackendHelper>();
 
+            var fileSystem = context.ServiceProvider.GetService<IFileSystem>();
+
             var pathResolver = context.ServiceProvider.GetService<IPathResolver>();
 
             if (context.DecompileType == OutputType.Transform)
             {
-                return this.DecompileTransform(context, backendHelper, pathResolver);
+                return this.DecompileTransform(context, backendHelper, fileSystem, pathResolver);
             }
             else
             {
-                return this.DecompileDatabase(context, backendHelper, pathResolver);
+                return this.DecompileDatabase(context, backendHelper, fileSystem, pathResolver);
             }
         }
 
-        private IWindowsInstallerDecompileResult DecompileDatabase(IWindowsInstallerDecompileContext context, IWindowsInstallerBackendHelper backendHelper, IPathResolver pathResolver)
+        private IWindowsInstallerDecompileResult DecompileDatabase(IWindowsInstallerDecompileContext context, IWindowsInstallerBackendHelper backendHelper, IFileSystem fileSystem, IPathResolver pathResolver)
         {
             var extractFilesFolder = context.SuppressExtractCabinets || (String.IsNullOrEmpty(context.CabinetExtractFolder) && String.IsNullOrEmpty(context.ExtractFolder)) ? null :
                 String.IsNullOrEmpty(context.CabinetExtractFolder) ? Path.Combine(context.ExtractFolder, "File") : context.CabinetExtractFolder;
 
             var outputType = context.TreatProductAsModule ? OutputType.Module : context.DecompileType;
-            var unbindCommand = new UnbindDatabaseCommand(this.Messaging, backendHelper, pathResolver, context.DecompilePath, null, outputType, context.ExtractFolder, extractFilesFolder, context.IntermediateFolder, enableDemodularization: true, skipSummaryInfo: false);
+            var unbindCommand = new UnbindDatabaseCommand(this.Messaging, backendHelper, fileSystem, pathResolver, context.DecompilePath, null, outputType, context.ExtractFolder, extractFilesFolder, context.IntermediateFolder, enableDemodularization: true, skipSummaryInfo: false);
             var output = unbindCommand.Execute();
             var extractedFilePaths = unbindCommand.ExportedFiles;
 
@@ -108,13 +109,13 @@ namespace WixToolset.Core.WindowsInstaller
             return result;
         }
 
-        private IWindowsInstallerDecompileResult DecompileTransform(IWindowsInstallerDecompileContext context, IWindowsInstallerBackendHelper backendHelper, IPathResolver pathResolver)
+        private IWindowsInstallerDecompileResult DecompileTransform(IWindowsInstallerDecompileContext context, IWindowsInstallerBackendHelper backendHelper, IFileSystem fileSystem, IPathResolver pathResolver)
         {
             var fileSystemExtensions = this.ExtensionManager.GetServices<IFileSystemExtension>();
 
-            var fileSystemManager = new FileSystemManager(fileSystemExtensions);
+            var fileSystemManager = new FileSystemManager(fileSystem, fileSystemExtensions);
 
-            var unbindCommand = new UnbindTransformCommand(this.Messaging, backendHelper, pathResolver, fileSystemManager, context.DecompilePath, context.ExtractFolder, context.IntermediateFolder);
+            var unbindCommand = new UnbindTransformCommand(this.Messaging, backendHelper, fileSystem, pathResolver, fileSystemManager, context.DecompilePath, context.ExtractFolder, context.IntermediateFolder);
             var output = unbindCommand.Execute();
 
             var result = context.ServiceProvider.GetService<IWindowsInstallerDecompileResult>();
diff --git a/src/wix/WixToolset.Core/Common.cs b/src/wix/WixToolset.Core/Common.cs
index f581e1a4..f5a9709d 100644
--- a/src/wix/WixToolset.Core/Common.cs
+++ b/src/wix/WixToolset.Core/Common.cs
@@ -362,44 +362,6 @@ namespace WixToolset.Core
         }
 
         /// <summary>
-        /// Recursively loops through a directory, changing an attribute on all of the underlying files.
-        /// An example is to add/remove the ReadOnly flag from each file.
-        /// </summary>
-        /// <param name="path">The directory path to start deleting from.</param>
-        /// <param name="fileAttribute">The FileAttribute to change on each file.</param>
-        /// <param name="messageHandler">The message handler.</param>
-        /// <param name="markAttribute">If true, add the attribute to each file. If false, remove it.</param>
-        private static void RecursiveFileAttributes(string path, FileAttributes fileAttribute, bool markAttribute, IMessaging messageHandler)
-        {
-            foreach (var subDirectory in Directory.GetDirectories(path))
-            {
-                RecursiveFileAttributes(subDirectory, fileAttribute, markAttribute, messageHandler);
-            }
-
-            foreach (var filePath in Directory.GetFiles(path))
-            {
-                var attributes = File.GetAttributes(filePath);
-                if (markAttribute)
-                {
-                    attributes = attributes | fileAttribute; // add to list of attributes
-                }
-                else if (fileAttribute == (attributes & fileAttribute)) // if attribute set
-                {
-                    attributes = attributes ^ fileAttribute; // remove from list of attributes
-                }
-
-                try
-                {
-                    File.SetAttributes(filePath, attributes);
-                }
-                catch (UnauthorizedAccessException)
-                {
-                    messageHandler.Write(WarningMessages.AccessDeniedForSettingAttributes(null, filePath));
-                }
-            }
-        }
-
-        /// <summary>
         /// Takes an id, and demodularizes it (if possible).
         /// </summary>
         /// <remarks>
diff --git a/src/wix/WixToolset.Core/ExtensibilityServices/FileSystem.cs b/src/wix/WixToolset.Core/ExtensibilityServices/FileSystem.cs
index 4269cabe..8cf7a872 100644
--- a/src/wix/WixToolset.Core/ExtensibilityServices/FileSystem.cs
+++ b/src/wix/WixToolset.Core/ExtensibilityServices/FileSystem.cs
@@ -3,6 +3,7 @@
 namespace WixToolset.Core.ExtensibilityServices
 {
     using System;
+    using System.ComponentModel;
     using System.IO;
     using System.Runtime.InteropServices;
     using System.Threading;
@@ -50,6 +51,25 @@ namespace WixToolset.Core.ExtensibilityServices
             this.ExecuteWithRetries(() => File.Move(source, destination));
         }
 
+        public FileStream OpenFile(string path, FileMode mode, FileAccess access, FileShare share)
+        {
+            const int maxRetries = 4;
+
+            for (var attempt = 1; attempt <= maxRetries; ++attempt)
+            {
+                try
+                {
+                    return File.Open(path, mode, access, share);
+                }
+                catch (Exception e) when (attempt < maxRetries && (e is IOException || e is SystemException || e is Win32Exception))
+                {
+                    Thread.Sleep(250);
+                }
+            }
+
+            throw new InvalidOperationException("Cannot reach this code");
+        }
+
         public void ExecuteWithRetries(Action action, int maxRetries = 4)
         {
             for (var attempt = 1; attempt <= maxRetries; ++attempt)
@@ -59,7 +79,7 @@ namespace WixToolset.Core.ExtensibilityServices
                     action();
                     break;
                 }
-                catch when (attempt < maxRetries)
+                catch (Exception e) when (attempt < maxRetries && (e is IOException || e is SystemException || e is Win32Exception))
                 {
                     Thread.Sleep(250);
                 }
diff --git a/src/wix/WixToolset.Core/LayoutCreator.cs b/src/wix/WixToolset.Core/LayoutCreator.cs
index 3e7ecf3a..c361f78a 100644
--- a/src/wix/WixToolset.Core/LayoutCreator.cs
+++ b/src/wix/WixToolset.Core/LayoutCreator.cs
@@ -112,15 +112,9 @@ namespace WixToolset.Core
             // Clean up temp files.
             foreach (var tempPath in uniqueTempPaths)
             {
-                try
-                {
-                    this.SplitUniqueFolders(intermediateFolder, tempPath, uniqueFolders);
+                this.SplitUniqueFolders(intermediateFolder, tempPath, uniqueFolders);
 
-                    File.Delete(tempPath);
-                }
-                catch // delete is best effort.
-                {
-                }
+                this.FileSystem.DeleteFile(tempPath);
             }
 
             // Clean up empty temp folders.
@@ -140,7 +134,7 @@ namespace WixToolset.Core
         {
             if (tempPath.StartsWith(intermediateFolder, StringComparison.OrdinalIgnoreCase))
             {
-                var folder = Path.GetDirectoryName(tempPath).Substring(intermediateFolder.Length);
+                var folder = Path.GetDirectoryName(tempPath.Substring(intermediateFolder.Length));
 
                 var parts = folder.Split(new[] { '\\', '/' }, StringSplitOptions.RemoveEmptyEntries);