#! /bin/sh
# SPDX-FileCopyrightText: (C) Eric S. Raymond <esr@thyrsus.com>
# SPDX-License-Identifier: MIT-0
#
# tapdiffer - Render diff between input and checkfile as a TAP report
#
# Usage: tapdiffer LEGEND CHECKFILE
#
# Output is a TAP report, ok if the diff is empty and not ok otherwise.
# A nonempty diff is shipped as a TAP YAML block following "not ok" 
# unless QUIET=1 in the environment.
#
# This code is intended to be embedded in your project. The author
# grants permission for it to be distributed under the prevailing
# license of your project if you choose, provided that license is
# OSD-compliant; otherwise the following SPDX tag incorporates the
# MIT No Attribution license by reference.
#
# A newer version may be available at https://gitlab.com/esr/tapview
# Check your last commit dqte for this file against the commit list
# there to see if it might be a good idea to update.
#
diffopts=-u
while getopts bn opt
do
    case $opt in
	b) diffopts=-ub;;
	*) echo "tapdiffer: unknown option ${opt}."; exit 1;;
    esac
done
# shellcheck disable=SC2004
shift $(($OPTIND - 1))

legend=$1
checkfile=$2

trap 'rm /tmp/tapdiff$$' EXIT HUP INT QUIT TERM

if diff --text "${diffopts}" "${checkfile}" - >/tmp/tapdiff$$
then
	echo "ok - ${legend}"
else
	echo "not ok - ${legend}"
	if [ ! "${QUIET}" = 1 ]
	then
		echo "  --- |"
		sed </tmp/tapdiff$$ -e 's/^/  /'
		echo "  ..."
	fi
fi

# end