Fix up a couple places that create a buffer or sourcetext from strings (

#73537)

For SourceText->ITextBuffer, use ITextBufferCloneService.Clone
For ITextSnapshot -> SourceText, use ITextSnaphshot.AsText extension method

src/EditorFeatures/Core.Wpf/Preview/PreviewFactoryService.cs

@@ -11,6 +11,7 @@
 using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Options;
+using Microsoft.CodeAnalysis.Text;
 using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Text.Differencing;
 using Microsoft.VisualStudio.Text.Editor;
@@ -32,6 +33,7 @@ internal class PreviewFactoryService : AbstractPreviewFactoryService<IWpfDiffere
         public PreviewFactoryService(
             IThreadingContext threadingContext,
             ITextBufferFactoryService textBufferFactoryService,
+            ITextBufferCloneService textBufferCloneService,
             IContentTypeRegistryService contentTypeRegistryService,
             IProjectionBufferFactoryService projectionBufferFactoryService,
             ITextEditorFactoryService textEditorFactoryService,
@@ -43,6 +45,7 @@ public PreviewFactoryService(
             IWpfDifferenceViewerFactoryService differenceViewerService)
             : base(threadingContext,
                   textBufferFactoryService,
+                  textBufferCloneService,
                   contentTypeRegistryService,
                   projectionBufferFactoryService,
                   editorOptionsService,

src/EditorFeatures/Core/Preview/AbstractPreviewFactoryService.cs

@@ -17,7 +17,6 @@
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Options;
 using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.SolutionCrawler;
 using Microsoft.CodeAnalysis.Text;
 using Microsoft.CodeAnalysis.Text.Shared.Extensions;
 using Microsoft.CodeAnalysis.Utilities;
@@ -36,6 +35,7 @@ namespace Microsoft.CodeAnalysis.Editor.Implementation.Preview;
 internal abstract class AbstractPreviewFactoryService<TDifferenceViewer>(
     IThreadingContext threadingContext,
     ITextBufferFactoryService textBufferFactoryService,
+    ITextBufferCloneService textBufferCloneService,
     IContentTypeRegistryService contentTypeRegistryService,
     IProjectionBufferFactoryService projectionBufferFactoryService,
     EditorOptionsService editorOptionsService,
@@ -48,6 +48,7 @@ internal abstract class AbstractPreviewFactoryService<TDifferenceViewer>(
     private const double DefaultZoomLevel = 0.75;
     private readonly ITextViewRoleSet _previewRoleSet = previewRoleSet;
     private readonly ITextBufferFactoryService _textBufferFactoryService = textBufferFactoryService;
+    private readonly ITextBufferCloneService _textBufferCloneService = textBufferCloneService;
     private readonly IContentTypeRegistryService _contentTypeRegistryService = contentTypeRegistryService;
     private readonly IProjectionBufferFactoryService _projectionBufferFactoryService = projectionBufferFactoryService;
     private readonly EditorOptionsService _editorOptionsService = editorOptionsService;
@@ -637,15 +638,15 @@ private async ValueTask<ITextBuffer> CreateNewPlainTextBufferAsync(TextDocument
 #pragma warning restore CA2007 // Consider calling ConfigureAwait on the awaited task
     }
 
-    private async ValueTask<ITextBuffer> CreateTextBufferCoreAsync(TextDocument document, IContentType? contentType, CancellationToken cancellationToken)
+    private async ValueTask<ITextBuffer> CreateTextBufferCoreAsync(TextDocument document, IContentType contentType, CancellationToken cancellationToken)
     {
         ThreadingContext.ThrowIfNotOnUIThread();
 
 #pragma warning disable CA2007 // Consider calling ConfigureAwait on the awaited task (containing method uses JTF)
         var text = await document.State.GetTextAsync(cancellationToken);
 #pragma warning restore CA2007 // Consider calling ConfigureAwait on the awaited task
 
-        var buffer = _textBufferFactoryService.CreateTextBuffer(text.ToString(), contentType);
+        var buffer = _textBufferCloneService.Clone(text, contentType);
 
         // Associate buffer with a text document with random file path to satisfy extensibility points expecting absolute file path.
         _textDocumentFactoryService.CreateTextDocument(buffer, Path.GetTempFileName());

src/VisualStudio/Core/Def/Preview/FileChange.cs

@@ -6,15 +6,12 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Threading;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Editor;
 using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Microsoft.CodeAnalysis.Text;
-using Microsoft.CodeAnalysis.Text.Shared.Extensions;
 using Microsoft.VisualStudio.ComponentModelHost;
 using Microsoft.VisualStudio.Language.Intellisense;
 using Microsoft.VisualStudio.LanguageServices.Implementation.Extensions;
@@ -33,7 +30,6 @@ internal class FileChange : AbstractChange
     private readonly IComponentModel _componentModel;
     public readonly DocumentId Id;
     private readonly ITextBuffer _buffer;
-    private readonly Encoding _encoding;
     private readonly IVsImageService2 _imageService;
 
     public FileChange(TextDocument left,
@@ -52,11 +48,12 @@ public FileChange(TextDocument left,
 
         _componentModel = componentModel;
         var bufferFactory = componentModel.GetService<ITextBufferFactoryService>();
+        var bufferCloneService = componentModel.GetService<ITextBufferCloneService>();
         var bufferText = left != null
             ? left.GetTextSynchronously(CancellationToken.None)
             : right.GetTextSynchronously(CancellationToken.None);
-        _buffer = bufferFactory.CreateTextBuffer(bufferText.ToString(), bufferFactory.InertContentType);
-        _encoding = bufferText.Encoding;
+
+        _buffer = bufferCloneService.Clone(bufferText, bufferFactory.InertContentType);
 
         this.Children = ComputeChildren(left, right, CancellationToken.None);
         this.parent = parent;
@@ -191,7 +188,7 @@ private SourceText UpdateBufferText()
             edit.ApplyAndLogExceptions();
         }
 
-        return SourceText.From(_buffer.CurrentSnapshot.GetText(), _encoding);
+        return _buffer.CurrentSnapshot.AsText();
     }
 
     public TextDocument GetOldDocument()

src/VisualStudio/Core/Impl/Options/AbstractOptionPreviewViewModel.cs

@@ -40,7 +40,7 @@ internal abstract class AbstractOptionPreviewViewModel : AbstractNotifyPropertyC
         private readonly IContentType _contentType;
         private readonly IEditorOptionsFactoryService _editorOptions;
         private readonly ITextEditorFactoryService _textEditorFactoryService;
-        private readonly ITextBufferFactoryService _textBufferFactoryService;
+        private readonly ITextBufferCloneService _textBufferCloneService;
         private readonly IProjectionBufferFactoryService _projectionBufferFactory;
         private readonly IContentTypeRegistryService _contentTypeRegistryService;
 
@@ -58,7 +58,7 @@ protected AbstractOptionPreviewViewModel(OptionStore optionStore, IServiceProvid
             _componentModel = (IComponentModel)serviceProvider.GetService(typeof(SComponentModel));
 
             _contentTypeRegistryService = _componentModel.GetService<IContentTypeRegistryService>();
-            _textBufferFactoryService = _componentModel.GetService<ITextBufferFactoryService>();
+            _textBufferCloneService = _componentModel.GetService<ITextBufferCloneService>();
             _textEditorFactoryService = _componentModel.GetService<ITextEditorFactoryService>();
             _projectionBufferFactory = _componentModel.GetService<IProjectionBufferFactoryService>();
             _editorOptions = _componentModel.GetService<IEditorOptionsFactoryService>();
@@ -140,7 +140,7 @@ public void UpdatePreview(string text)
             var formattingOptions = formattingService.GetFormattingOptions(OptionStore, fallbackFormattingOptions);
             var formatted = Formatter.FormatAsync(document, formattingOptions, CancellationToken.None).WaitAndGetResult(CancellationToken.None);
 
-            var textBuffer = _textBufferFactoryService.CreateTextBuffer(formatted.GetTextSynchronously(CancellationToken.None).ToString(), _contentType);
+            var textBuffer = _textBufferCloneService.Clone(formatted.GetTextSynchronously(CancellationToken.None), _contentType);
 
             var container = textBuffer.AsTextContainer();