From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 06 Jul 2010 02:35:44 GMT
Subject: Re: [PATCH v4 7/7] t/README: Document the do's and don'ts of tests
Message-ID: <7vaaq58hhb.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1278082789-19872-8-git-send-email-avarab@gmail.com>

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.