message: add test_extract_error_message
diff: @@ -101,3 +101,15 @@ class TestMySQLEngineSpecsDbEngineSpec(TestDbEngineSpec):
  assert MySQLEngineSpec.is_db_column_type_match(
  type_str, DbColumnType.TEMPORAL
  ) is (col_type == DbColumnType.TEMPORAL)
  +
  + def test_extract_error_message(self):
  + from MySQLdb._exceptions import OperationalError
  +
  + message = "Unknown table 'BIRTH_NAMES1' in information_schema"
  + exception = OperationalError(message)
  + extracted_message = MySQLEngineSpec._extract_error_message(exception)
  + assert extracted_message == message
  +
  + exception = OperationalError(123, message)
  + extracted_message = MySQLEngineSpec._extract_error_message(exception)
  + assert extracted_message == message
  