Bash function wrapping with minimal eval

wrap_example.bash

#!/usr/bin/env bash


wrap() {
	local old_name="${1:?get fuct}"
	
	local new_name="${2:?get fuct}"
	_temp_function() {
		echo "wrapping the old one!"
		_old_function_call_placeholder param
		echo "after calling the old one!"
	};


	local new_body=$( declare -f "_temp_function"  | tail -n +2 )
	eval "$(printf "%s()\n%s" $new_name "${new_body/_old_function_call_placeholder/$old_name}")"
	unset _temp_function
}

foo() {
	echo "this is foo!"
}
# define "bar" as wrapping "foo"
wrap foo bar

bar