FIx intellisense cache not refreshing (#831)

* FIx intellisense cache not refreshing

* Remove extra newlines

* Output label to provide more useful information in case of error

src/Microsoft.SqlTools.Hosting/Hosting/Protocol/EventContext.cs

@@ -26,7 +26,7 @@ namespace Microsoft.SqlTools.Hosting.Protocol
             this.messageWriter = messageWriter;
         }
 
-        public async Task SendEvent<TParams>(
+        public virtual async Task SendEvent<TParams>(
             EventType<TParams> eventType,
             TParams eventParams)
         {

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

@@ -628,6 +628,7 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
                 {
                     await Task.Run(() =>
                     {
+                        // Get the current ScriptInfo if one exists so we can lock it while we're rebuilding the cache
                         ScriptParseInfo scriptInfo = GetScriptParseInfo(connInfo.OwnerUri, createIfNotExists: false);
                         if (scriptInfo != null && scriptInfo.IsConnected &&
                             Monitor.TryEnter(scriptInfo.BuildingMetadataLock, LanguageService.OnConnectionWaitTimeout))
@@ -635,6 +636,8 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
                             try
                             {
                                 this.BindingQueue.AddConnectionContext(connInfo, featureName: "LanguageService", overwrite: true);
+                                RemoveScriptParseInfo(rebuildParams.OwnerUri);
+                                UpdateLanguageServiceOnConnection(connInfo).Wait();
                             }
                             catch (Exception ex)
                             {

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

@@ -3,6 +3,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.SqlTools.ServiceLayer.IntegrationTests.Utility;
@@ -157,5 +158,63 @@ namespace Microsoft.SqlTools.ServiceLayer.IntegrationTests.LanguageServer
             Assert.True(LanguageService.Instance.BindingQueue.BindingContextMap.ContainsKey(connectionKey));
             Assert.False(object.ReferenceEquals(LanguageService.Instance.BindingQueue.BindingContextMap[connectionKey].ServerConnection, orgServerConnection));
         }
+
+        /// <summary>
+        /// Verifies that clearing the Intellisense cache correctly refreshes the cache with new info from the DB.
+        /// </summary>
+        [Fact]
+        public async Task RebuildIntellisenseCacheClearsScriptParseInfoCorrectly()
+        {
+            var testDb = SqlTestDb.CreateNew(TestServerType.OnPrem, false, null, null, "LangSvcTest");
+            try
+            {
+                var connectionInfoResult = LiveConnectionHelper.InitLiveConnectionInfo(testDb.DatabaseName);
+
+                var langService = LanguageService.Instance;
+                await langService.UpdateLanguageServiceOnConnection(connectionInfoResult.ConnectionInfo);
+                var queryText = "SELECT * FROM dbo.";
+                connectionInfoResult.ScriptFile.SetFileContents(queryText);
+
+                var textDocumentPosition =
+                    connectionInfoResult.TextDocumentPosition ??
+                    new TextDocumentPosition()
+                    {
+                        TextDocument = new TextDocumentIdentifier
+                        {
+                            Uri = connectionInfoResult.ScriptFile.ClientFilePath
+                        },
+                        Position = new Position
+                        {
+                            Line = 0,
+                            Character = queryText.Length
+                        }
+                    };
+
+                // First check that we don't have any items in the completion list as expected
+                var initialCompletionItems = langService.GetCompletionItems(
+                    textDocumentPosition, connectionInfoResult.ScriptFile, connectionInfoResult.ConnectionInfo);
+
+                Assert.True(initialCompletionItems.Length == 0, $"Should not have any completion items initially. Actual : [{string.Join(',', initialCompletionItems.Select(ci => ci.Label))}]");
+
+                // Now create a table that should show up in the completion list
+                testDb.RunQuery("CREATE TABLE dbo.foo(col1 int)");
+
+                // And refresh the cache
+                await langService.HandleRebuildIntelliSenseNotification(
+                    new RebuildIntelliSenseParams() { OwnerUri = connectionInfoResult.ScriptFile.ClientFilePath },
+                    new TestEventContext());
+
+                // Now we should expect to see the item show up in the completion list
+                var afterTableCreationCompletionItems = langService.GetCompletionItems(
+                    textDocumentPosition, connectionInfoResult.ScriptFile, connectionInfoResult.ConnectionInfo);
+
+                Assert.True(afterTableCreationCompletionItems.Length == 1, $"Should only have a single completion item after rebuilding Intellisense cache. Actual : [{string.Join(',', initialCompletionItems.Select(ci => ci.Label))}]");
+                Assert.True(afterTableCreationCompletionItems[0].InsertText == "foo", $"Expected single completion item 'foo'. Actual : [{string.Join(',', initialCompletionItems.Select(ci => ci.Label))}]");
+            }
+            finally
+            {
+                testDb.Cleanup();
+            }
+        }
     }
 }

test/Microsoft.SqlTools.ServiceLayer.Test.Common/TestEventContext.cs

@@ -0,0 +1,19 @@
+using System.Threading.Tasks;
+using Microsoft.SqlTools.Hosting.Protocol;
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.Test.Common
+{
+    /// <summary>
+    /// Simple EventContext for testing that just swallows all events.
+    /// </summary>
+    public class TestEventContext : EventContext
+    {
+        public override async Task SendEvent<TParams>(
+            EventType<TParams> eventType,
+            TParams eventParams)
+        {
+            await Task.FromResult(0);
+        }
+    }
+}