[Bug] params value of RPC "method":"gateway_device_deleted" is not a JSON encoded string

[skewty]

Describe the bug The params value of RPC payload is not valid JSON when method=gateway_device_deleted is sent by back-end.

To Reproduce

import json
RAW_MQTT_PAYLOAD = b'{"method":"gateway_device_deleted","params":"Temp Device 1701728569"}'
rpc_data = json.loads(RAW_MQTT_PAYLOAD)
rpc_params = json.loads(rpc_data.get("params", "{}"))

json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Expected behavior params field should have surrounding " character so it is valid JSON.

Docs at https://thingsboard.io/docs/user-guide/rpc/ state params field "value is a JSON.".

A string without surrounding quotes is not JSON.

This is a bug in your back-end and in your gateway.

This bug existed in 3.5. and continues to exist in 3.6..

[skewty]

Perhaps it is better to change the value of params to have a JSON object schema instead.

example:

{ 
  "version": 2,
  "deletedDeviceName": "Temp Device 1701728569" 
}

instead of

Temp Device 1701728569

The schema / params change would also make sense for gateway_device_renamed as well.

{ 
   "version": 2,
   "previousDeviceName": "Temp Device 1701728569",
   "currentDeviceName": "My Device"  
}

instead of

{ "Temp Device 1701728569": "My Device" }

Then params would always be a JSON object.

[skewty]

Looking further into RPC params and I see more inconsistencies.

Example: gateway stats uses camelCase (which is good / expected)

{
  "eventsProduced": 0, 
  "eventsSent": 0
}

but gateway version uses snake_case (which is bad / unexpected)

{
  "current_version": "0",
  "latest_version": "0"
}

gateway devices should be an array of objects so it can be validated using JSON schema but instead it returns a mapping which is (bad / unexpected)

gateway ping uses a string which could be easily changed to

{ 
   "version": 2,
   "timestamp": "2023-12-05T11:40:12.431363Z"
}

It seems logical for all gateway responses to be a JSON object so they can share more code path.