Tests are not strictly necessary, but good practice in software development. For the snmp plugins i tend to do unit test which simply test each of the functions in the by it self. I made some examples for you plugin:
The @pytest.mark.parametrize part just calls the function below multiple times with different inputs. However the first two checks only have one set of inputs not multiple.
If you have installed Docker, VSCode and the Remote Containers it should allow you to open the project in a container. You should then be able to run for example pytest. If this does not work I would need to know what error you get while opening the project in a container.
Regards Marius