Language Service diagnostics and autocomplete (#9)

* Merge master to dev (#4)

* Misc. clean-ups related to removing unneeded PowerShell Language Service code.
* Remove unneeded files and clean up remaining code.
* Enable file change tracking with Workspace and EditorSession.

* Setup standard src, test folder structure.  Add unit test project.

* Actually stage the deletes.  Update .gitignore

* Integrate SqlParser into the onchange diagnostics to provide error messages.

* Add tests for the language service diagnostics

* Initial implementation for autocomplete.

* Switch to using sys.tables for autocomplete
Move some code into a better class

* Delete unused csproj file.

* Add nuget.config to pickup SQL Parser nuget package

test/ServiceHost.Test/LanguageServer/LanguageServiceTests.cs

@@ -0,0 +1,126 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.EditorServices;
+using Microsoft.SqlTools.EditorServices.Session;
+using Microsoft.SqlTools.LanguageSupport;
+using Microsoft.SqlTools.Test.Connection;
+using Microsoft.SqlTools.Test.Utility;
+using Xunit;
+
+namespace Microsoft.SqlTools.Test.LanguageServer
+{
+    /// <summary>
+    /// Tests for the ServiceHost Language Service tests
+    /// </summary>
+    public class LanguageServiceTests
+    {
+        #region "Diagnostics tests"
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void ParseSelectStatementWithoutErrors()
+        {
+            // sql statement with no errors
+            const string sqlWithErrors = "SELECT * FROM sys.objects";
+
+            // get the test service 
+            LanguageService service = TestObjects.GetTestLanguageService();
+
+            // parse the sql statement
+            var scriptFile = new ScriptFile();
+            scriptFile.SetFileContents(sqlWithErrors);
+            ScriptFileMarker[] fileMarkers = service.GetSemanticMarkers(scriptFile);
+
+            // verify there are no errors
+            Assert.Equal(0, fileMarkers.Length);
+        }
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void ParseSelectStatementWithError()
+        {
+            // sql statement with errors
+            const string sqlWithErrors = "SELECT *** FROM sys.objects";
+
+            // get test service
+            LanguageService service = TestObjects.GetTestLanguageService();
+
+            // parse sql statement
+            var scriptFile = new ScriptFile();
+            scriptFile.SetFileContents(sqlWithErrors);
+            ScriptFileMarker[] fileMarkers = service.GetSemanticMarkers(scriptFile);
+
+            // verify there is one error
+            Assert.Equal(1, fileMarkers.Length);
+
+            // verify the position of the error
+            Assert.Equal(9, fileMarkers[0].ScriptRegion.StartColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.StartLineNumber);
+            Assert.Equal(10, fileMarkers[0].ScriptRegion.EndColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.EndLineNumber);
+        }
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void ParseMultilineSqlWithErrors()
+        {
+            // multiline sql with errors
+            const string sqlWithErrors = 
+                "SELECT *** FROM sys.objects;\n" +
+                "GO\n" +
+                "SELECT *** FROM sys.objects;\n";
+
+            // get test service
+            LanguageService service = TestObjects.GetTestLanguageService();
+
+            // parse sql
+            var scriptFile = new ScriptFile();
+            scriptFile.SetFileContents(sqlWithErrors);
+            ScriptFileMarker[] fileMarkers = service.GetSemanticMarkers(scriptFile);
+
+            // verify there are two errors
+            Assert.Equal(2, fileMarkers.Length);
+
+            // check position of first error
+            Assert.Equal(9, fileMarkers[0].ScriptRegion.StartColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.StartLineNumber);
+            Assert.Equal(10, fileMarkers[0].ScriptRegion.EndColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.EndLineNumber);
+
+            // check position of second error
+            Assert.Equal(9, fileMarkers[1].ScriptRegion.StartColumnNumber);
+            Assert.Equal(3, fileMarkers[1].ScriptRegion.StartLineNumber);
+            Assert.Equal(10, fileMarkers[1].ScriptRegion.EndColumnNumber);
+            Assert.Equal(3, fileMarkers[1].ScriptRegion.EndLineNumber);
+        }
+
+        #endregion
+
+        #region "Autocomplete Tests"
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void AutocompleteTest()
+        {
+            var autocompleteService = TestObjects.GetAutoCompleteService();
+            var connectionService = TestObjects.GetTestConnectionService();
+            var connectionResult = connectionService.Connect(TestObjects.GetTestConnectionDetails());
+            var sqlConnection = connectionService.ActiveConnections[connectionResult.ConnectionId];
+            autocompleteService.UpdateAutoCompleteCache(sqlConnection);
+        }
+
+        #endregion
+    }
+}
+