Testing bash-preexec
Note on test conditions
When writing test conditions, use [ ... ] instead of [[ ... ]] since the
former are supported by Bats on Bash versions before 4.1. In particular, macOS
uses Bash 3.2, and [[ ... ]] tests always pass on macOS.
In some cases, you may want to use a feature unique to [[ ... ]] such as
pattern matching ([[ $name = a* ]]) or regular expressions ([[ $(date) =~ ^Fri\ ...\ 13 ]]). In those cases, use the following pattern to replace “bare”
[[ ... ]].
[[ ... ]] || return 1
References: