Capture file content on open instead of save (#54643)

src/Features/Core/Portable/EditAndContinue/EditAndContinueWorkspaceService.cs

@@ -97,7 +97,7 @@ public void OnSourceFileUpdated(Document document)
             foreach (var debuggingSession in GetActiveDebuggingSessions())
             {
                 // fire and forget
-                _ = Task.Run(() => debuggingSession.OnSourceFileUpdatedAsync(document));
+                _ = Task.Run(() => debuggingSession.OnSourceFileUpdatedAsync(document)).ReportNonFatalErrorAsync();
             }
         }
 

src/VisualStudio/Core/Def/Implementation/EditAndContinue/VisualStudioWorkspaceEditAndContinueListener.cs

@@ -0,0 +1,56 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Composition;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.EditAndContinue;
+using Microsoft.CodeAnalysis.Host;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Roslyn.Utilities;
+
+namespace Microsoft.VisualStudio.LanguageServices.EditAndContinue
+{
+    /// <summary>
+    /// Connects <see cref="VisualStudioWorkspace"/> to the ServiceHub services.
+    /// Launches ServiceHub if it is not running yet and starts services that push information from <see cref="VisualStudioWorkspace"/> to the ServiceHub process.
+    /// </summary>
+    [ExportEventListener(WellKnownEventListeners.Workspace, WorkspaceKind.Host), Shared]
+    internal sealed class VisualStudioWorkspaceEditAndContinueListener : IEventListener<object>, IEventListenerStoppable
+    {
+        [ImportingConstructor]
+        [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+        public VisualStudioWorkspaceEditAndContinueListener()
+        {
+        }
+
+        public void StartListening(Workspace workspace, object serviceOpt)
+        {
+            if (workspace is not VisualStudioWorkspace)
+            {
+                return;
+            }
+
+            workspace.DocumentOpened += WorkspaceDocumentOpened;
+        }
+
+        public void StopListening(Workspace workspace)
+        {
+            if (workspace is not VisualStudioWorkspace)
+            {
+                return;
+            }
+
+            workspace.DocumentOpened -= WorkspaceDocumentOpened;
+        }
+
+        private void WorkspaceDocumentOpened(object? sender, DocumentEventArgs e)
+        {
+            var proxy = new RemoteEditAndContinueServiceProxy(e.Document.Project.Solution.Workspace);
+            _ = Task.Run(() => proxy.OnSourceFileUpdatedAsync(e.Document, CancellationToken.None)).ReportNonFatalErrorAsync();
+        }
+    }
+}