How to use deviceNameTopicExpression in Thingsboard IoT Gateway with custom_mqtt_uplink_converter?

Question

I have MQTT topics looking like this:

ABC123DE/devices/sensor1/controls/temperature

where

• sensor1 is device name, and
• temperature is device type

I want them both to be passed in TB.

My mqtt.json:

  ...
  "mapping": [
    {
      "topicFilter": "+/devices/+/controls/+",
      "converter": {
        "type": "custom",
        "deviceNameTopicExpression": "(?<=/controls/)(.*?)(?=$)",
        "deviceTypeTopicExpression": "(?<=devices\/)(.*?)(?=\/controls)",
        "extension": "TestMqttConverter",
        "extension-config": {}
      }
    }
  ],
...

My test_mqtt_uplink_converter.py:

...
class TestMqttConverter(MqttUplinkConverter):
    def __init__(self, config):
        self.__config = config.get('converter')
        self.dict_result = {}

    def convert(self, topic, body):
        try:
            self.dict_result["telemetry"] = [{"test": "123"}]

            return self.dict_result

        except Exception as e:
            log.exception('Error in converter')
            log.exception(e)

When I publish:

mosquitto_pub -t ABC123DE/devices/sensor1/controls/temperatire -m 100

I receive this error:

''2020-07-01 13:38:03' - ERROR - tb_utility - 62 - deviceName is empty in data: {"telemetry": [{"test": "123"}]}'
''2020-07-01 13:38:03' - ERROR - tb_gateway_service - 263 - Data from MQTT Broker Connector connector is invalid.'
''2020-07-01 13:38:03' - INFO - mqtt_connector - 343 - Successfully converted message from topic ABC123DE/devices/sensor1/controls/temperatire'

What else should I do to make it work?

Where are these values processed?

I've checked my expressions with https://pythex.org/