Linux

Shellcheck is a great tool for scripting.

When I'm building a new script, I usually add the following function to the script and run the function before anything else. The script will exit immediately if any issues are found so I have a chance to correct things. If no issues are found, the script will simply continue.

It's small and simple so it's easy to remove when I'm done building a script.

script_check() {
    if ! shellcheck "${0}"; then
        exit 1
    fi
}

script_check

Shellcheck has helped me learn a lot about scripting and I strongly recommend using it too.