#!/bin/sh -e
test -f "$1" || { >&2 echo "usage: ${0##*/} <existing_script>"; exit 1; }
test -x "$(which entr)" || exit 2
test -x "$(which shellcheck)" || exit 3

a=$(readlink -f "$1")
if test -r "${1}_test"
then b=$(readlink -f "${1}_test")
else b=''
fi

if test -n "$2"
then
	test -d "$2" || { >&2 echo "$2: no dir"; exit 1; }
	wa="$2/$1"
	wb="$2/${1}_test"
else
	wa="$a"
	wb="$b"
fi

test -f "$b" || b="$HOME/bin/no_tests"

tmux split-window -p 95 "vim $a"
tmux split-window -p 40 -dh \
"ls $wa $wb | entr -rc sh -c 'echo $a;shellcheck $a $b && sh $b'"