Update tests to access the original source text

Author: dibarbet

src/EditorFeatures/CSharpTest/PdbSourceDocument/AbstractPdbSourceDocumentTests.cs

@@ -155,6 +155,14 @@ protected static async Task GenerateFileAndVerifyAsync(
 
             var masWorkspace = service.TryGetWorkspace();
 
+            using var fileStream = File.OpenRead(file.FilePath);
+            var sourceText = SourceText.From(fileStream);
+            var text = SourceText.From(File.ReadAllText(file.FilePath));
+
+            var pdbService = (PdbSourceDocumentMetadataAsSourceFileProvider)workspace.ExportProvider.GetExportedValues<IMetadataAsSourceFileProvider>().Single(s => s is PdbSourceDocumentMetadataAsSourceFileProvider);
+
+            var documentInfo = pdbService.GetTestAccessor().Documents[file.FilePath];
+            masWorkspace!.OnDocumentAdded(documentInfo.DocumentInfo);
             var document = masWorkspace!.CurrentSolution.Projects.First().Documents.First(d => d.FilePath == file.FilePath);
 
             // Mapping the project from the generated document should map back to the original project
@@ -330,4 +338,15 @@ protected static string GetPdbPath(string path)
     {
         return Path.Combine(path, "reference.pdb");
     }
+
+    private class StaticSourceTextContainer(SourceText sourceText) : SourceTextContainer
+    {
+        public override SourceText CurrentText => sourceText;
+
+        public override event EventHandler<TextChangeEventArgs> TextChanged
+        {
+            add { }
+            remove { }
+        }
+    }
 }

src/Features/Core/Portable/PdbSourceDocument/PdbSourceDocumentMetadataAsSourceFileProvider.cs

@@ -429,6 +429,23 @@ public void CleanupGeneratedFiles(MetadataAsSourceWorkspace workspace)
         _sourceLinkEnabledProjects.Clear();
         _implementationAssemblyLookupService.Clear();
     }
+
+    internal TestAccessor GetTestAccessor()
+    {
+        return new TestAccessor(this);
+    }
+
+    internal readonly struct TestAccessor
+    {
+        private readonly PdbSourceDocumentMetadataAsSourceFileProvider _instance;
+
+        internal TestAccessor(PdbSourceDocumentMetadataAsSourceFileProvider instance)
+        {
+            _instance = instance;
+        }
+
+        public ImmutableDictionary<string, SourceDocumentInfo> Documents => _instance._fileToDocumentInfoMap.ToImmutableDictionary();
+    }
 }
 
 internal sealed record SourceDocument(string FilePath, SourceHashAlgorithm ChecksumAlgorithm, ImmutableArray<byte> Checksum, byte[]? EmbeddedTextBytes, string? SourceLinkUrl);