Initial commit of SqlTools Service API

ServiceHost/MessageProtocol/IMessageSender.cs

@@ -0,0 +1,22 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Threading.Tasks;
+
+namespace Microsoft.PowerShell.EditorServices.Protocol.MessageProtocol
+{
+    internal interface IMessageSender
+    {
+        Task SendEvent<TParams>(
+            EventType<TParams> eventType,
+            TParams eventParams);
+
+        Task<TResult> SendRequest<TParams, TResult>(
+            RequestType<TParams, TResult> requestType,
+            TParams requestParams,
+            bool waitForResponse);
+    }
+}
+