Re: [PATCH] bisect: improve output when bad commit is found

From: Junio C Hamano <gitster@pobox.com>
Date: May 12, 2015, 02:08 UTC
Message-ID: <xmqqbnhq1r9t.fsf@gitster.dls.corp.google.com>
In-Reply-To: <20150511231125.GC18112@tsaunders-iceball.corp.tor1.mozilla.com>

Trevor Saunders <tbsaunde@tbsaunde.org> writes:

Show 10 quoted lines

>> > +	file=$1
>> > +	hash=$2
>> > +	grep "the first bad commit is" $file || return $?
>> > +	grep $hash $file || return $?
>> 
>> Is it OK to have these strings anywhere in the $file?
>
> Its not great, but the test seems to log multiple invokations of git
> bisect into the same file, so there may be text about previous runs
> before we are told which commit is bad.

So if we had a previous entry that happens to match $hash, even if the current test stopped and pointed at a different thing, this test declares a success?

This function knows how the $file should end, so it might be more sensible to craft the expected output and compare the tail end of the $file with it, something like:

	(
		echo "The first bad commit is"
                git show -s "$hash"
	) >expect &&
        cnt=$(wc -l <expect) &&
        tail -n $cnt "$file" >actual &&
        test_cmp expect actual

perhaps?