Add fix for SendEvent causing test to fail (#195)

Add flag in ServiceHost to ignore SendEvent errors

src/Microsoft.SqlTools.ServiceLayer/Hosting/Protocol/ProtocolEndpoint.cs

@@ -9,6 +9,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.SqlTools.ServiceLayer.Hosting.Protocol.Channel;
 using Microsoft.SqlTools.ServiceLayer.Hosting.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Utility;
 
 namespace Microsoft.SqlTools.ServiceLayer.Hosting.Protocol
 {
@@ -28,6 +29,14 @@ namespace Microsoft.SqlTools.ServiceLayer.Hosting.Protocol
         private Dictionary<string, TaskCompletionSource<Message>> pendingRequests =
             new Dictionary<string, TaskCompletionSource<Message>>();
 
+        /// <summary>
+        /// When true, SendEvent will ignore exceptions and write them
+        /// to the log instead. Intended to be used for test scenarios
+        /// where SendEvent throws exceptions unrelated to what is
+        /// being tested.
+        /// </summary>
+        internal static bool SendEventIgnoreExceptions = false;
+
         /// <summary>
         /// Gets the MessageDispatcher which allows registration of
         /// handlers for requests, responses, and events that are
@@ -194,37 +203,52 @@ namespace Microsoft.SqlTools.ServiceLayer.Hosting.Protocol
             EventType<TParams> eventType,
             TParams eventParams)
         {
-            if (!this.protocolChannel.IsConnected)
+            try
             {
-                throw new InvalidOperationException("SendEvent called when ProtocolChannel was not yet connected");
+                if (!this.protocolChannel.IsConnected)
+                {
+                    throw new InvalidOperationException("SendEvent called when ProtocolChannel was not yet connected");
+                }
+
+                // Some events could be raised from a different thread.
+                // To ensure that messages are written serially, dispatch
+                // dispatch the SendEvent call to the message loop thread.
+
+                if (!this.MessageDispatcher.InMessageLoopThread)
+                {
+                    TaskCompletionSource<bool> writeTask = new TaskCompletionSource<bool>();
+
+                    this.MessageDispatcher.SynchronizationContext.Post(
+                        async (obj) =>
+                        {
+                            await this.protocolChannel.MessageWriter.WriteEvent(
+                                eventType,
+                                eventParams);
+
+                            writeTask.SetResult(true);
+                        }, null);
+
+                    return writeTask.Task;
+                }
+                else
+                {
+                    return this.protocolChannel.MessageWriter.WriteEvent(
+                        eventType,
+                        eventParams);
+                }
             }
-
+            catch (Exception ex)
-            // Some events could be raised from a different thread.
-            // To ensure that messages are written serially, dispatch
-            // dispatch the SendEvent call to the message loop thread.
-
-            if (!this.MessageDispatcher.InMessageLoopThread)
             {
-                TaskCompletionSource<bool> writeTask = new TaskCompletionSource<bool>();
+                if (SendEventIgnoreExceptions)
-
+                {
-                this.MessageDispatcher.SynchronizationContext.Post(
+                    Logger.Write(LogLevel.Verbose, "Exception in SendEvent " + ex.ToString());
-                    async (obj) =>
+                }
-                    {
+                else
-                        await this.protocolChannel.MessageWriter.WriteEvent(
+                {
-                            eventType,
+                    throw;
-                            eventParams);
+                }
-
-                        writeTask.SetResult(true);
-                    }, null);
-
-                return writeTask.Task;
-            }
-            else
-            {
-                return this.protocolChannel.MessageWriter.WriteEvent(
-                    eventType,
-                    eventParams);
             }
+            return Task.FromResult(false);
         }
 
         #endregion

test/Microsoft.SqlTools.ServiceLayer.Test/LanguageServer/LanguageServiceTests.cs

@@ -3,7 +3,6 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
-using Microsoft.SqlServer.Management.SqlParser.Parser;
 using Microsoft.SqlTools.ServiceLayer.Connection;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices.Completion;
@@ -290,6 +289,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.LanguageServer
         {
             // When we make a connection to a live database
             ScriptFile scriptFile;
+            Hosting.ServiceHost.SendEventIgnoreExceptions = true;
             ConnectionInfo connInfo = TestObjects.InitLiveConnectionInfo(out scriptFile);
 
             // And we place the cursor after a function that should prompt for signature help
@@ -308,12 +308,15 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.LanguageServer
                 }
             };
 
-            // If we have a valid ScriptParseInfo and the SQL has already been parsed
+            // If the SQL has already been parsed
             var service = LanguageService.Instance;
-            ScriptParseInfo parseInfo = service.GetScriptParseInfo(scriptFile.ClientFilePath);
             await service.UpdateLanguageServiceOnConnection(connInfo);
 
-            // We should get back a non-null SignatureHelp 
+            // We should get back a non-null ScriptParseInfo
+            ScriptParseInfo parseInfo = service.GetScriptParseInfo(scriptFile.ClientFilePath);
+            Assert.NotNull(parseInfo);
+
+            // And we should get back a non-null SignatureHelp
             SignatureHelp signatureHelp = service.GetSignatureHelp(textDocument, scriptFile);
             Assert.NotNull(signatureHelp);
         }