Switch to using sys.tables for autocomplete

Move some code into a better class

src/ServiceHost/Connection/SqlConnection.cs

@@ -52,8 +52,10 @@ namespace Microsoft.SqlTools.EditorServices.Connection
         /// <returns></returns>
         public IEnumerable<string> GetServerObjects()
         {
+            // Select the values from sys.tables to give a super basic
+            // autocomplete experience.  This will be replaced by SMO.
             SqlCommand command = connection.CreateCommand();
-            command.CommandText = "SELECT name FROM sys.objects";
+            command.CommandText = "SELECT name FROM sys.tables";
             command.CommandTimeout = 15;
             command.CommandType = CommandType.Text;
             var reader = command.ExecuteReader();

src/ServiceHost/LanguageSupport/AutoCompleteService.cs

@@ -4,6 +4,7 @@
 //
 
 using Microsoft.SqlTools.EditorServices.Connection;
+using Microsoft.SqlTools.EditorServices.Protocol.LanguageServer;
 using System;
 using System.Collections.Generic;
 
@@ -20,8 +21,14 @@ namespace Microsoft.SqlTools.LanguageSupport
         private static Lazy<AutoCompleteService> instance 
             = new Lazy<AutoCompleteService>(() => new AutoCompleteService());
 
+        /// <summary>
+        /// The current autocomplete candidate list
+        /// </summary>
         private IEnumerable<string> autoCompleteList;
 
+        /// <summary>
+        /// Gets the current autocomplete candidate list
+        /// </summary>
         public IEnumerable<string> AutoCompleteList
         {
             get
@@ -41,9 +48,65 @@ namespace Microsoft.SqlTools.LanguageSupport
             }
         }
 
+        /// <summary>
+        /// Update the cached autocomplete candidate list when the user connects to a database
+        /// </summary>
+        /// <param name="connection"></param>
         public void UpdateAutoCompleteCache(ISqlConnection connection)
         {
             this.autoCompleteList = connection.GetServerObjects();
         }
+
+        /// <summary>
+        /// Return the completion item list for the current text position
+        /// </summary>
+        /// <param name="textDocumentPosition"></param>
+        public CompletionItem[] GetCompletionItems(TextDocumentPosition textDocumentPosition)
+        {
+            var completions = new List<CompletionItem>();
+
+            int i = 0;
+
+            // the completion list will be null is user not connected to server
+            if (this.AutoCompleteList != null)
+            {
+                foreach (var autoCompleteItem in this.AutoCompleteList)
+                {
+                    // convert the completion item candidates into CompletionItems
+                    completions.Add(new CompletionItem()
+                    {
+                        Label = autoCompleteItem,
+                        Kind = CompletionItemKind.Keyword,
+                        Detail = autoCompleteItem + " details",
+                        Documentation = autoCompleteItem + " documentation",
+                        TextEdit = new TextEdit
+                        {
+                            NewText = autoCompleteItem,
+                            Range = new Range
+                            {
+                                Start = new Position
+                                {
+                                    Line = textDocumentPosition.Position.Line,
+                                    Character = textDocumentPosition.Position.Character
+                                },
+                                End = new Position
+                                {
+                                    Line = textDocumentPosition.Position.Line,
+                                    Character = textDocumentPosition.Position.Character + 5
+                                }
+                            }
+                        }
+                    });
+
+                    // only show 50 items
+                    if (++i == 50)
+                    {
+                        break;
+                    }
+                }
+            }
+            return completions.ToArray();
+        }
+        
     }
 }

src/ServiceHost/Server/LanguageServer.cs

@@ -175,15 +175,38 @@ namespace Microsoft.SqlTools.EditorServices.Protocol.Server
             await Task.FromResult(true);
         }
 
+        /// <summary>
+        /// Handle the file open notification
+        /// </summary>
+        /// <param name="openParams"></param>
+        /// <param name="eventContext"></param>
         protected Task HandleDidOpenTextDocumentNotification(
             DidOpenTextDocumentNotification openParams,
             EventContext eventContext)
         {
             Logger.Write(LogLevel.Verbose, "HandleDidOpenTextDocumentNotification");
+
+            // read the SQL file contents into the ScriptFile
+            ScriptFile openedFile =
+                editorSession.Workspace.GetFileBuffer(
+                    openParams.Uri,
+                    openParams.Text);
+
+            // run diagnostics on the opened file
+            this.RunScriptDiagnostics(
+                new ScriptFile[] { openedFile },
+                editorSession,
+                eventContext);
+
             return Task.FromResult(true);
         }
 
-         protected Task HandleDidCloseTextDocumentNotification(
+        /// <summary>
+        /// Handle the close document notication
+        /// </summary>
+        /// <param name="closeParams"></param>
+        /// <param name="eventContext"></param>
+        protected Task HandleDidCloseTextDocumentNotification(
             TextDocumentIdentifier closeParams,
             EventContext eventContext)
         {
@@ -257,62 +280,20 @@ namespace Microsoft.SqlTools.EditorServices.Protocol.Server
             await Task.FromResult(true);
         }
 
+        /// <summary>
+        /// Handles the completion list request
+        /// </summary>
+        /// <param name="textDocumentPosition"></param>
+        /// <param name="requestContext"></param>
         protected async Task HandleCompletionRequest(
             TextDocumentPosition textDocumentPosition,
             RequestContext<CompletionItem[]> requestContext)
         {
             Logger.Write(LogLevel.Verbose, "HandleCompletionRequest");
 
-            var connectionService = ConnectionService.Instance;
-            if (connectionService.ActiveConnections.Count > 0)
-            {
-                AutoCompleteService.Instance.UpdateAutoCompleteCache(
-                    connectionService.ActiveConnections.First().Value);
-            }
-
-            var autoCompleteList = AutoCompleteService.Instance.AutoCompleteList;
-            var completions = new List<CompletionItem>();
-
-            int i = 0;
-            if (autoCompleteList != null)
-            {
-                foreach (var autoCompleteItem in autoCompleteList)
-                {
-                    completions.Add(new CompletionItem()
-                    {
-                        Label = autoCompleteItem,
-                        Kind = CompletionItemKind.Keyword,
-                        Detail = autoCompleteItem + " details",
-                        Documentation = autoCompleteItem + " documentation",
-                        //SortText = "SortText",
-                        TextEdit = new TextEdit
-                        {
-                            NewText = "New Text",
-                            Range = new Range
-                            {
-                                Start = new Position
-                                {
-                                    Line = textDocumentPosition.Position.Line,
-                                    Character = textDocumentPosition.Position.Character
-                                },
-                                End = new Position
-                                {
-                                    Line = textDocumentPosition.Position.Line,
-                                    Character = textDocumentPosition.Position.Character + 5
-                                }
-                            }
-                        }
-                    });
-
-                    // only show 50 items
-                    if (++i == 50)
-                    {
-                        break;
-                    }
-                }
-            }
-
-            await requestContext.SendResult(completions.ToArray());
+            // get teh current list of completion items and return to client
+            var completionItems = AutoCompleteService.Instance.GetCompletionItems(textDocumentPosition);
+            await requestContext.SendResult(completionItems);
         }
 
         protected async Task HandleCompletionResolveRequest(