#!/usr/bin/env bash
#
# Converts assertion failure text involving two mutations to a diff.
#

cmd="colordiff -u"

while getopts ":d:" opt; do
    case $opt in
    d)
        cmd="$OPTARG";;
    *)
        echo "Usage: $0 [-d diff_command] [<path-to-test-output-file>]" 1>&2
        exit 1;;
    esac
done
shift $((OPTIND-1))

file="$1"
if [ -z "$file" -o "$file" = "-" ]; then
    tmpfile=$(mktemp)
    cat > "$tmpfile"
    file="$tmpfile"
fi

function filter {
    sed 's/@0x[0-9a-f]*//g'
}

$cmd <(sed -n '/expected/,/got:/p' "$file" | head -n-1 | sed 's/.*expected /&\n/' | filter) \
     <(sed -n '/got:/,/^$/p' "$file" | sed 's/.*got: /&\n/' | filter) | less -R

if [ -n "$tmpfile" ]; then
    rm -f "$tmpfile"
fi