Using Docker:

docker build -t dev . && docker run -it --name dev -v $(pwd):/app:z --env-file .env dev to start the container named dev and mount a volume of the current folder into the container

In a new terminal window, run docker exec -it dev /bin/bash to jump into a bash prompt in the container

To shut everything down, run docker stop dev && docker rm dev

To add a test, add a file_name_for_test.rb file to the test folder and add require 'test_helper' at the top.