From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: Tue, 06 Jul 2010 12:50:08 GMT
Subject: Re: [PATCH v4 7/7] t/README: Document the do's and don'ts of tests
Message-ID: <AANLkTimvyxNq3GAnwNZJEm6U5Jn7TlaedLZk12O9g8xe@mail.gmail.com>
In-Reply-To: <7vaaq58hhb.fsf@alter.siamese.dyndns.org>

On Tue, Jul 6, 2010 at 02:35, Junio C Hamano <gitster@pobox.com> wrote:
> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
>
>> +Do's, don'ts & things to keep in mind
>> +-------------------------------------
>> +
>> +Here's a few examples of things you probably should and shouldn't do
>> +when writing tests.
>
> "Here are" perhaps?
>
>> +Do:
>> +
>> + - Put as much code as possible inside test_expect_success and other
>> +   assertions.
>> +
>> +   Even code that isn't a test per se, but merely some setup code
>> +   should be inside a test assertion if at all possible. Test scripts
>> +   should only have trivial code outside of their assertions.
>
> Let's make it even stronger; "should only have trivial" -> "shouldn't have
> any ... unless there is a good reason."
>
>> +Don't:
>> +
>> + - exit() within a <script> part.
>> +
>> +   The harness will catch this as a programming error of the test.
>> +   Use test_done instead if you need to stop the tests early (see
>> +   "Skipping tests" below).
>> +
>> + - Break the TAP output
>> +
>> +   The raw output from your test might be interpreted by a TAP
>> +   harness. You usually don't have to worry about that. TAP harnesses
>
> I'd recommend dropping "You usually...about that"  You do care, but the
> limitation may be not so severe.
>
>> +   will ignore everything they don't know about, but don't step on
>> +   their toes in these areas:
>> +
>> +   - Don't print lines like "$x..$y" where $x and $y are integers.
>> +
>> +   - Don't print lines that begin with "ok" or "not ok".
>> +
>> +   A TAP harness expect a line that begins with either "ok" and "not
>> +   ok" to signal a test passed or failed (and our harness already
>> +   produces such lines), so your script shouldn't emit such lines to
>> +   their output.
>> +
>> +   You can glean some further possible issues from the TAP grammar
>> +   (see http://search.cpan.org/perldoc?TAP::Parser::Grammar#TAP_Grammar)
>> +   but the best indication is to just run the tests with prove(1),
>> +   it'll complain if anything is amiss.
>> +
>> +Keep in mind:
>> +
>> + - That what you print to stderr and stdout is usually ignored
>> +
>> +   Inside <script> part, the standard output and standard error
>
> Splitting the above into two sentences (or a header and a body) makes it
> unclear that your "usually" comes from the earlier "Do Put as much code
> inside test_expect_success...".  I think you can simply drop "That what
> you print ... ignored".
>
> Everything else in the series looked good.  Thanks.

All of these rewordings (the "t/README: proposed rewording..." commit
in pu) look good.

    Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>