Add missing API to IVSTypeScriptDiagnosticService (#59751)

src/Features/Core/Portable/ExternalAccess/VSTypeScript/Api/IVSTypeScriptDiagnosticService.cs

@@ -2,14 +2,18 @@
 // 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.Collections.Immutable;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Diagnostics;
 
 namespace Microsoft.CodeAnalysis.ExternalAccess.VSTypeScript.Api
 {
     internal interface IVSTypeScriptDiagnosticService
     {
         Task<ImmutableArray<VSTypeScriptDiagnosticData>> GetPushDiagnosticsAsync(Workspace workspace, ProjectId projectId, DocumentId documentId, object id, bool includeSuppressedDiagnostics, CancellationToken cancellationToken);
+
+        IDisposable RegisterDiagnosticsUpdatedEventHandler(Action<VSTypeScriptDiagnosticsUpdatedArgsWrapper> action);
     }
 }

src/Features/Core/Portable/ExternalAccess/VSTypeScript/Api/VSTypeScriptDiagnosticsUpdatedArgsWrapper.cs

@@ -0,0 +1,22 @@
+// 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 Microsoft.CodeAnalysis.Diagnostics;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.VSTypeScript.Api
+{
+    internal readonly struct VSTypeScriptDiagnosticsUpdatedArgsWrapper
+    {
+        internal readonly DiagnosticsUpdatedArgs UnderlyingObject;
+
+        public VSTypeScriptDiagnosticsUpdatedArgsWrapper(DiagnosticsUpdatedArgs underlyingObject)
+            => UnderlyingObject = underlyingObject;
+
+        public Solution? Solution
+            => UnderlyingObject.Solution;
+
+        public DocumentId? DocumentId
+            => UnderlyingObject.DocumentId;
+    }
+}

src/Features/Core/Portable/ExternalAccess/VSTypeScript/VSTypeScriptDiagnosticService.cs

@@ -33,5 +33,26 @@ public async Task<ImmutableArray<VSTypeScriptDiagnosticData>> GetPushDiagnostics
             var result = await _service.GetPushDiagnosticsAsync(workspace, projectId, documentId, id, includeSuppressedDiagnostics, _globalOptions.GetDiagnosticMode(InternalDiagnosticsOptions.NormalDiagnosticMode), cancellationToken).ConfigureAwait(false);
             return result.SelectAsArray(data => new VSTypeScriptDiagnosticData(data));
         }
+
+        public IDisposable RegisterDiagnosticsUpdatedEventHandler(Action<VSTypeScriptDiagnosticsUpdatedArgsWrapper> action)
+            => new EventHandlerWrapper(_service, action);
+
+        private sealed class EventHandlerWrapper : IDisposable
+        {
+            private readonly IDiagnosticService _service;
+            private readonly EventHandler<DiagnosticsUpdatedArgs> _handler;
+
+            internal EventHandlerWrapper(IDiagnosticService service, Action<VSTypeScriptDiagnosticsUpdatedArgsWrapper> action)
+            {
+                _service = service;
+                _handler = (sender, args) => action(new VSTypeScriptDiagnosticsUpdatedArgsWrapper(args));
+                _service.DiagnosticsUpdated += _handler;
+            }
+
+            public void Dispose()
+            {
+                _service.DiagnosticsUpdated -= _handler;
+            }
+        }
     }
 }