#!/usr/bin/env bash
# Make sure file has a trailing newline

f="$1"

if [ -z "$f" ]; then
	echo "usage: $0 <file>"
	exit 1
fi

if [ ! -f "$f" ]; then
	exit 0
fi

if [[ $(tail -c1 "$f") ]]; then
	echo "$f: No newline at end of file"
	echo '' >> "$f"
	exit 1
fi

if [[ ! $(tail -c2 "$f") ]]; then
	echo "$f: Extra trailing newline"
	exit 1
fi

if grep -q $'\r' "$f"; then
	echo "$f: DOS-style newlines"
	dos2unix "$f" &> /dev/null
	exit 1
fi

if grep -q $'[\t ]$' "$f"; then
	echo "$f: Trailing whitespace"
	sed -i $'s/[ \t]*$//' "$f"
	exit 1
fi

exit 0