Re: [PATCH v2 4/8] test-lib-functions: add and use test_cmp_cmd

["René Scharfe" <l.s.r@web.de>]

Am 02.12.2022 um 01:06 schrieb Ævar Arnfjörð Bjarmason:
> Add a "test_cmp_cmd" helper for the common pattern discussed in the
> documentation being added here to "t/test-lib-functions.sh".
>
> This implementation leaves the door open for extending this helper
> past its obvious limitations, such as:
>
> 	test_cmp_cmd "some" "lines" -- <some-cmd>
> 	test_cmp_cmd --stdin <some-cmd> <expect
> 	test_cmp_cmd --ignore-stderr "output" <some-cmd>
>
> By using this in we'll catch cases where "git" or "test-tool"
> errors (such as segfaults or abort()) were previously hidden, and we'd
> either pass the test, or fail in some subsequent assertion.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---

> diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
> index 796093a7b32..0e8e0f808e3 100644
> --- a/t/test-lib-functions.sh
> +++ b/t/test-lib-functions.sh
> @@ -1274,6 +1274,24 @@ test_cmp_rev () {
>  	fi
>  }
>
> +# test_cmp_cmd is a convenience helper for doing the more verbose:
> +#
> +#	echo something >expect &&
> +#	<some-command-and-args> >actual &&
> +#	test_cmp expect actual
> +#
> +# As:
> +#
> +#	test_cmp_cmd something <some-command-and-args>
> +test_cmp_cmd () {
> +	local expect="$1" &&
> +	shift &&
> +	printf "%s\n" "$expect" >expect &&
> +	"$@" >actual 2>err &&
> +	test_must_be_empty err
> +	test_cmp expect actual

err, expect and actual are common filenames used in tests.
Clobbering them might be surprising.  Perhaps at least add some
prefix (e.g. name them test_cmp_cmd_expect etc.), like other
functions in that script do, to avoid collisions?

> +}
> +
>  # Compare paths respecting core.ignoreCase
>  test_cmp_fspath () {
>  	if test "x$1" = "x$2"