THIS. Why does this:

    if age < 18 {
      echo "I'm not an adult yet"
    } else {
      echo "I'm an adult"
    }

compile to this:

    __0_age=30;
    if [ $(echo ${__0_age} '<' 18 | bc -l | sed '/\./ s/\. \{0,1\} 0\{1,\}$//') != 0 ]; then
      echo "I'm not an adult yet"
    else
      echo "I'm an adult"
    fi

instead of this:

    __0_age=30;
    if [[ ${__0_age} -lt 18 ]]; then
    ...

If you're going to compile to Bash, then use Bash-isms.

EDIT: `-gt` is POSIX, but tbf if there's no input sanitization, then bash (or sh) will choke on the float. In that case, as long as you aren't trying to round, you could use parameter substitution to truncate:

    __0_age=17.6;
    if [[ ${__0_age%%\.*} -lt 18 ]]; then
    ...

EDIT2: TIL that parameter substitution is POSIX [0] Section 2.6.2

[0]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V...