Autocomplete bug fixes (#43)

Fix-up the autocomplete support to better handle binding timeouts.
Also provide a default keyword suggestion list.

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

@@ -0,0 +1,98 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.SqlTools.ServiceLayer.Hosting.Protocol;
+using Microsoft.SqlTools.ServiceLayer.LanguageServices.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
+{
+    /// <summary>
+    /// Main class for Language Service functionality including anything that reqires knowledge of
+    /// the language to perfom, such as definitions, intellisense, etc.
+    /// </summary>
+    public static class DiagnosticsHelper
+    {
+        /// <summary>
+        /// Send the diagnostic results back to the host application
+        /// </summary>
+        /// <param name="scriptFile"></param>
+        /// <param name="semanticMarkers"></param>
+        /// <param name="eventContext"></param>
+        internal static async Task PublishScriptDiagnostics(
+            ScriptFile scriptFile,
+            ScriptFileMarker[] semanticMarkers,
+            EventContext eventContext)
+        {
+            var allMarkers = scriptFile.SyntaxMarkers != null
+                    ? scriptFile.SyntaxMarkers.Concat(semanticMarkers)
+                    : semanticMarkers;
+
+            // Always send syntax and semantic errors.  We want to 
+            // make sure no out-of-date markers are being displayed.
+            await eventContext.SendEvent(
+                PublishDiagnosticsNotification.Type,
+                new PublishDiagnosticsNotification
+                {
+                    Uri = scriptFile.ClientFilePath,
+                    Diagnostics =
+                       allMarkers
+                            .Select(GetDiagnosticFromMarker)
+                            .ToArray()
+                });
+        }
+
+        /// <summary>
+        /// Convert a ScriptFileMarker to a Diagnostic that is Language Service compatible
+        /// </summary>
+        /// <param name="scriptFileMarker"></param>
+        /// <returns></returns>
+        internal static Diagnostic GetDiagnosticFromMarker(ScriptFileMarker scriptFileMarker)
+        {
+            return new Diagnostic
+            {
+                Severity = MapDiagnosticSeverity(scriptFileMarker.Level),
+                Message = scriptFileMarker.Message,
+                Range = new Range
+                {
+                    Start = new Position
+                    {
+                        Line = scriptFileMarker.ScriptRegion.StartLineNumber - 1,
+                        Character = scriptFileMarker.ScriptRegion.StartColumnNumber - 1
+                    },
+                    End = new Position
+                    {
+                        Line = scriptFileMarker.ScriptRegion.EndLineNumber - 1,
+                        Character = scriptFileMarker.ScriptRegion.EndColumnNumber - 1
+                    }
+                }
+            };
+        }
+
+        /// <summary>
+        /// Map ScriptFileMarker severity to Diagnostic severity
+        /// </summary>
+        /// <param name="markerLevel"></param>        
+        internal static DiagnosticSeverity MapDiagnosticSeverity(ScriptFileMarkerLevel markerLevel)
+        {
+            switch (markerLevel)
+            {
+                case ScriptFileMarkerLevel.Error:
+                    return DiagnosticSeverity.Error;
+
+                case ScriptFileMarkerLevel.Warning:
+                    return DiagnosticSeverity.Warning;
+
+                case ScriptFileMarkerLevel.Information:
+                    return DiagnosticSeverity.Information;
+
+                default:
+                    return DiagnosticSeverity.Error;
+            }
+        }
+    }
+}