Re: [PATCH 2/8] t7900: setup and tear down clones

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 17, 2023, 20:13 UTC
Message-ID: <xmqqwmvlgg71.fsf@gitster.g>
In-Reply-To: <e3987cda75e4db72393f85de4bbb71d2ebaa097b.1697319294.git.code@khaugsbakk.name>

Kristoffer Haugsbakk <code@khaugsbakk.name> writes:

Show 28 quoted lines

> Test `loose-objects task` depends on the two clones setup in `prefetch
> multiple remotes`.
>
> Reuse the two clones setup and tear down the clones afterwards in both
> tests.
>
> Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
> ---
>  t/t7900-maintenance.sh | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
> index ca86b2ba687..ebc207f1a58 100755
> --- a/t/t7900-maintenance.sh
> +++ b/t/t7900-maintenance.sh
> @@ -145,6 +145,12 @@ test_expect_success 'run --task=prefetch with no remotes' '
>  '
>  
>  test_expect_success 'prefetch multiple remotes' '
> +	test_when_finished rm -r clone1 &&
> +	test_when_finished rm -r clone2 &&
> +	test_when_finished git remote remove remote1 &&
> +	test_when_finished git remote remove remote2 &&
> +	test_when_finished git tag --delete one &&
> +	test_when_finished git tag --delete two &&
>  	git clone . clone1 &&
>  	git clone . clone2 &&
>  	git remote add remote1 "file://$(pwd)/clone1" &&

As I already said in my response to the cover letter, while I am surprised that the series managed to make each step (and it alone) succeed after the set-up (applaud!), I am not sure if it is really worth doing. As the business of test scripts is to test git, and it means that we should always assume that we are dealing with a potentially broken version of git. By running so many git subcommands in test_when_finished, each of them may be from a buggy implementation of git, we cannot be really sure that we are resetting the environment to the pristine state. We should strive to do as little as possible in test_when_finished.

Show 10 quoted lines

> @@ -175,6 +181,22 @@ test_expect_success 'prefetch multiple remotes' '
>  '
>  
>  test_expect_success 'loose-objects task' '
> +	test_when_finished rm -r clone1 &&
> +	test_when_finished rm -r clone2 &&
> +	test_when_finished git remote remove remote1 &&
> +	test_when_finished git remote remove remote2 &&
> +	test_when_finished git tag --delete one &&
> +	test_when_finished git tag --delete two &&

Ditto.

Show 9 quoted lines

> +	git clone . clone1 &&
> +	git clone . clone2 &&
> +	git remote add remote1 "file://$(pwd)/clone1" &&
> +	git remote add remote2 "file://$(pwd)/clone2" &&
> +	git -C clone1 switch -c one &&
> +	git -C clone2 switch -c two &&
> +	test_commit -C clone1 one &&
> +	test_commit -C clone2 two &&
> +	git fetch --all &&

This is even worse; it has to redo much of what the previous test did. Developers cannot be reasonably expected to maintain this duplication when we need to change the earlier test.

While I am impressed that "set-up + individual single test" was made to work, I am not convinced that the changes that took us to get there are reasonable. The end result looks much less maintainable and more wasteful with duplicated steps.

Thanks.