Clear and rebuild IntelliSense cache (#238)

* Stage changes to other machine

* IntelliSense cache rebuild command

* Move to other machine

* Add a test for overwriting binding queue.

* Move event handler into lanaguageservice.cs

src/Microsoft.SqlTools.ServiceLayer/LanguageServices/LanguageService.cs

@@ -212,6 +212,7 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
             serviceHost.SetRequestHandler(HoverRequest.Type, HandleHoverRequest);
             serviceHost.SetRequestHandler(CompletionRequest.Type, HandleCompletionRequest);
             serviceHost.SetRequestHandler(DefinitionRequest.Type, HandleDefinitionRequest);
+            serviceHost.SetEventHandler(RebuildIntelliSenseNotification.Type, HandleRebuildIntelliSenseNotification);
 
             // Register a no-op shutdown task for validation of the shutdown logic
             serviceHost.RegisterShutdownTask(async (shutdownParams, shutdownRequestContext) =>
@@ -442,6 +443,62 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
             await Task.FromResult(true);
         }
 
+        /// <summary>
+        /// Handle the rebuild IntelliSense cache notification
+        /// </summary>
+        public async Task HandleRebuildIntelliSenseNotification(
+            RebuildIntelliSenseParams configChangeParams,
+            EventContext eventContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleRebuildIntelliSenseNotification");
+
+            // Skip closing this file if the file doesn't exist
+            var scriptFile = this.CurrentWorkspace.GetFile(configChangeParams.OwnerUri);
+            if (scriptFile == null)
+            {
+                return;
+            }
+
+            ConnectionInfo connInfo;
+            LanguageService.ConnectionServiceInstance.TryFindConnection(
+                scriptFile.ClientFilePath,
+                out connInfo);
+
+            await Task.Run(() =>
+            {
+                ScriptParseInfo scriptInfo = GetScriptParseInfo(connInfo.OwnerUri, createIfNotExists: false);
+                if (scriptInfo != null && scriptInfo.IsConnected && 
+                    Monitor.TryEnter(scriptInfo.BuildingMetadataLock, LanguageService.OnConnectionWaitTimeout))
+                {
+                    try
+                    {
+                        this.BindingQueue.AddConnectionContext(connInfo, overwrite: true);
+                    }
+                    catch (Exception ex)
+                    {
+                        Logger.Write(LogLevel.Error, "Unknown error " + ex.ToString());
+                    }
+                    finally
+                    {
+                        // Set Metadata Build event to Signal state.
+                        Monitor.Exit(scriptInfo.BuildingMetadataLock);
+                    }
+                }
+
+                // if not in the preview window and diagnostics are enabled then run diagnostics
+                if (!IsPreviewWindow(scriptFile)
+                    && WorkspaceService<SqlToolsSettings>.Instance.CurrentSettings.IsDiagnositicsEnabled)
+                {
+                    RunScriptDiagnostics(
+                        new ScriptFile[] { scriptFile },
+                        eventContext);
+                }
+
+                // Send a notification to signal that autocomplete is ready
+                ServiceHost.Instance.SendEvent(IntelliSenseReadyNotification.Type, new IntelliSenseReadyParams() {OwnerUri = connInfo.OwnerUri});
+            });            
+        }
+
         /// <summary>
         /// Handle the file configuration change notification
         /// </summary>