Invoke callback when auto-enlisting a transaction.

Signed-off-by: Bradley Grainger <[email protected]>

Author: bgrainger

src/MySqlConnector/MySqlConnection.cs

@@ -551,6 +551,13 @@ internal async Task OpenAsync(IOBehavior? ioBehavior, CancellationToken cancella
 					ActivitySourceHelper.CopyTags(m_session!.ActivityTags, activity);
 					m_hasBeenOpened = true;
 					SetState(ConnectionState.Open);
+
+					if (ConnectionOpenedCallback is { } autoEnlistConnectionOpenedCallback)
+					{
+						cancellationToken.ThrowIfCancellationRequested();
+						await autoEnlistConnectionOpenedCallback(new(this, MySqlConnectionOpenedConditions.None), cancellationToken).ConfigureAwait(false);
+					}
+
 					return;
 				}
 			}

tests/IntegrationTests/TransactionScopeTests.cs

@@ -886,6 +886,38 @@ public void Bug1348()
 
 		Assert.True(rollbacked, $"First branch transaction '{xid}1' not rolled back");
 	}
+
+	[Fact]
+	public void ConnectionOpenedCallbackAutoEnlistInTransaction()
+	{
+		var connectionOpenedCallbackCount = 0;
+		var connectionOpenedConditions = MySqlConnectionOpenedConditions.None;
+		using var dataSource = new MySqlDataSourceBuilder(AppConfig.ConnectionString)
+			.UseConnectionOpenedCallback((ctx, token) =>
+			{
+				connectionOpenedCallbackCount++;
+				connectionOpenedConditions = ctx.Conditions;
+				return default;
+			})
+			.Build();
+
+		using (var transactionScope = new TransactionScope())
+		{
+			using (var conn = dataSource.OpenConnection())
+			{
+				Assert.Equal(1, connectionOpenedCallbackCount);
+				Assert.Equal(MySqlConnectionOpenedConditions.New, connectionOpenedConditions);
+			}
+
+			using (var conn = dataSource.OpenConnection())
+			{
+				Assert.Equal(2, connectionOpenedCallbackCount);
+				Assert.Equal(MySqlConnectionOpenedConditions.None, connectionOpenedConditions);
+			}
+
+			transactionScope.Complete();
+		}
+	}
 #endif
 
 	readonly DatabaseFixture m_database;