Hello again @Eclipse,
Your script isn’t working because Alpine base images don’t have GNU bash. Seems like you’re running your bash script prematurely. I’ve seen a topic like this similar before.
In the context of a CI system, it is extremely important to remove the volumes: line that mounts a local directory over your container’s /app directory: in the build instructions, you can see why it would cause problems specifically in Docker Compose.
In a real world environment (and say not like a school) I’d personally suggest running both of these tools in a non-Docker environment. Via the Docker syntax you can ideally setup your unit tests without hard-to-setup context like a database container as well.
FYI: I’d also run further tests based on network calls into the container.
-Montana