Batch Start Notification (#169)

This change is part of the progressive results code. It will submit a notification from the service layer to indicate when execution of a batch has completed. This notification will contain the selection for batch, execution start time, and its ID. This will enable the extension to produce a header for the batch before the batch completes, in order to make it more clear to the user that execution is going on.

* Adding new event for batch start

* Unit tests

* Fixing comments as per @kevcunnane

test/Microsoft.SqlTools.ServiceLayer.Test/QueryExecution/Execution/BatchTests.cs

@@ -46,22 +46,34 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
             // ... The summary should have the same info
             Assert.False(batch.Summary.HasError);
             Assert.Equal(Common.Ordinal, batch.Summary.Id);
-            Assert.Empty(batch.Summary.ResultSetSummaries);
-            Assert.Empty(batch.Summary.Messages);
+            Assert.Null(batch.Summary.ResultSetSummaries);
+            Assert.Null(batch.Summary.Messages);
             Assert.Equal(0, batch.Summary.Selection.StartLine);
             Assert.NotEqual(default(DateTime).ToString("o"), batch.Summary.ExecutionStart); // Should have been set at construction
-            Assert.Equal(default(DateTime).ToString("o"), batch.Summary.ExecutionEnd);
-            Assert.Equal((default(DateTime) - DateTime.Parse(batch.Summary.ExecutionStart)).ToString(), batch.Summary.ExecutionElapsed);
+            Assert.Null(batch.Summary.ExecutionEnd);
+            Assert.Null(batch.Summary.ExecutionElapsed);
         }
 
+        /// <summary>
+        /// Note: This test also tests the start notification feature
+        /// </summary>
         [Fact]
         public void BatchExecuteNoResultSets()
         {
-            // Setup: Create a callback for batch completion
-            BatchSummary batchSummaryFromCallback = null;
-            Batch.BatchAsyncEventHandler batchCallback = b =>
+            // Setup: 
+            // ... Create a callback for batch start
+            BatchSummary batchSummaryFromStart = null;
+            Batch.BatchAsyncEventHandler batchStartCallback = b =>
             {
-                batchSummaryFromCallback = b.Summary;
+                batchSummaryFromStart = b.Summary;
+                return Task.FromResult(0);
+            };
+
+            // ... Create a callback for batch completion
+            BatchSummary batchSummaryFromCompletion = null;
+            Batch.BatchAsyncEventHandler batchCompleteCallback = b =>
+            {
+                batchSummaryFromCompletion = b.Summary;
                 return Task.FromResult(0);
             };
 
@@ -76,7 +88,8 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
             // If I execute a query that should get no result sets
             var fileStreamFactory = Common.GetFileStreamFactory(new Dictionary<string, byte[]>());
             Batch batch = new Batch(Common.StandardQuery, Common.SubsectionDocument, Common.Ordinal, fileStreamFactory);
-            batch.BatchCompletion += batchCallback;
+            batch.BatchStart += batchStartCallback;
+            batch.BatchCompletion += batchCompleteCallback;
             batch.ResultSetCompletion += resultSetCallback;
             batch.Execute(GetConnection(Common.CreateTestConnectionInfo(null, false)), CancellationToken.None).Wait();
 
@@ -96,21 +109,32 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
             // ... There should be a message for how many rows were affected
             Assert.Equal(1, batch.ResultMessages.Count());
 
+            // ... The callback for batch start should have been called
+            // ... The info from it should have been basic
+            Assert.NotNull(batchSummaryFromStart);
+            Assert.False(batchSummaryFromStart.HasError);
+            Assert.Equal(Common.Ordinal, batchSummaryFromStart.Id);
+            Assert.Equal(Common.SubsectionDocument, batchSummaryFromStart.Selection);
+            Assert.True(DateTime.Parse(batchSummaryFromStart.ExecutionStart) > default(DateTime));
+            Assert.Null(batchSummaryFromStart.ResultSetSummaries);
+            Assert.Null(batchSummaryFromStart.Messages);
+            Assert.Null(batchSummaryFromStart.ExecutionElapsed);
+            Assert.Null(batchSummaryFromStart.ExecutionEnd);
+
             // ... The callback for batch completion should have been fired
-            Assert.NotNull(batchSummaryFromCallback);
+            // ... The summary should match the expected info
+            Assert.NotNull(batchSummaryFromCompletion);
+            Assert.False(batchSummaryFromCompletion.HasError);
+            Assert.Equal(Common.Ordinal, batchSummaryFromCompletion.Id);
+            Assert.Equal(0, batchSummaryFromCompletion.ResultSetSummaries.Length);
+            Assert.Equal(1, batchSummaryFromCompletion.Messages.Length);
+            Assert.Equal(Common.SubsectionDocument, batchSummaryFromCompletion.Selection);
+            Assert.True(DateTime.Parse(batchSummaryFromCompletion.ExecutionStart) > default(DateTime));
+            Assert.True(DateTime.Parse(batchSummaryFromCompletion.ExecutionEnd) > default(DateTime));
+            Assert.NotNull(batchSummaryFromCompletion.ExecutionElapsed);
 
             // ... The callback for the result set should NOT have been fired
             Assert.False(resultCallbackFired);
-
-            // ... The summary should have the same info
-            Assert.False(batch.Summary.HasError);
-            Assert.Equal(Common.Ordinal, batch.Summary.Id);
-            Assert.Equal(0, batch.Summary.ResultSetSummaries.Length);
-            Assert.Equal(1, batch.Summary.Messages.Length);
-            Assert.Equal(0, batch.Summary.Selection.StartLine);
-            Assert.True(DateTime.Parse(batch.Summary.ExecutionStart) > default(DateTime));
-            Assert.True(DateTime.Parse(batch.Summary.ExecutionEnd) > default(DateTime));
-            Assert.NotNull(batch.Summary.ExecutionElapsed);
         }
 
         [Fact]
@@ -239,9 +263,18 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
         [Fact]
         public void BatchExecuteInvalidQuery()
         {
-            // Setup: Create a callback for batch completion
+            // Setup:
+            // ... Create a callback for batch start
+            bool batchStartCalled = false;
+            Batch.BatchAsyncEventHandler batchStartCallback = b =>
+            {
+                batchStartCalled = true;
+                return Task.FromResult(0);
+            };
+             
+            // ... Create a callback for batch completion
             BatchSummary batchSummaryFromCallback = null;
-            Batch.BatchAsyncEventHandler batchCallback = b =>
+            Batch.BatchAsyncEventHandler batchCompleteCallback = b =>
             {
                 batchSummaryFromCallback = b.Summary;
                 return Task.FromResult(0);
@@ -258,7 +291,8 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
             // If I execute a batch that is invalid
             var fileStreamFactory = Common.GetFileStreamFactory(new Dictionary<string, byte[]>());
             Batch batch = new Batch(Common.StandardQuery, Common.SubsectionDocument, Common.Ordinal, fileStreamFactory);
-            batch.BatchCompletion += batchCallback;
+            batch.BatchStart += batchStartCallback;
+            batch.BatchCompletion += batchCompleteCallback;
             batch.ResultSetCompletion += resultSetCallback;
             batch.Execute(GetConnection(ci), CancellationToken.None).Wait();
 
@@ -276,6 +310,9 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
 
             // ... The callback for batch completion should have been fired
             Assert.NotNull(batchSummaryFromCallback);
+
+            // ... The callback for batch start should have been fired
+            Assert.True(batchStartCalled);
         }
 
         [Fact]
@@ -293,20 +330,24 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
             Assert.True(batch.HasExecuted, "The batch should have been marked executed.");
             Assert.False(batch.HasError, "The batch should not have an error");
 
-            // Setup for part 2: Create a callback for batch completion
-            BatchSummary batchSummaryFromCallback = null;
-            bool completionCallbackFired = false;
-            Batch.BatchAsyncEventHandler callback = b =>
+            // Setup for part 2: 
+            // ... Create a callback for batch completion
+            Batch.BatchAsyncEventHandler completeCallback = b =>
             {
-                completionCallbackFired = true;
-                batchSummaryFromCallback = b.Summary;
-                return Task.FromResult(0);
+                throw new Exception("Batch completion callback should not have been called");
+            };
+
+            // ... Create a callback for batch start
+            Batch.BatchAsyncEventHandler startCallback = b =>
+            {
+                throw new Exception("Batch start callback should not have been called");
             };
 
             // If I execute it again
             // Then:
             // ... It should throw an invalid operation exception
-            batch.BatchCompletion += callback;
+            batch.BatchStart += startCallback;
+            batch.BatchCompletion += completeCallback;
             await Assert.ThrowsAsync<InvalidOperationException>(() =>
                 batch.Execute(GetConnection(ci), CancellationToken.None));
 
@@ -315,10 +356,6 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.QueryExecution.Execution
             Assert.True(batch.HasExecuted, "The batch should still be marked executed.");
             Assert.NotEmpty(batch.ResultSets);
             Assert.NotEmpty(batch.ResultSummaries);
-
-            // ... The callback for batch completion should not have been fired for the second run
-            Assert.False(completionCallbackFired);
-            Assert.Null(batchSummaryFromCallback);
         }
 
         [Theory]