Re: [PATCHv6 1/2] submodule tests: don't use itself as a submodule

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 9, 2017, 02:33 UTC
Message-ID: <xmqqh959ynb4.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170105192904.1107-2-sbeller@google.com>

Stefan Beller <sbeller@google.com> writes:

> This provides an easier way to have submodules in tests, by just setting
> TEST_CREATE_SUBMODULE to a non empty string, similar to
> TEST_NO_CREATE_REPO.

Yuck.

I find it doubtful that it is a good idea to create two submodule repositories by merely dot-including the test-lib.sh; I find it doubly doubtful that it is a good idea to make test_create_repo pay attention to the special variable to implement that.

I am OK with a solution where callers that set TEST_CREATE_SUBMODULE variable in this patch to instead have an explicit call

	test_create_repo --submodule pretzel

That would be a lot more obvious.

The primary reason why I hate the implementation in this patch is that it is very easy for a test that says TEST_CREATE_SUBMODULE upfront, only to get the initial test repository (which everybody else gets) with two test submodules, to later gain a test that wants to use a separate repository and call "test_create_repo". It will always get the pretzel submodules, which may or may not match what the test writer who adds a new test needs.

> Make use of it in those tests that add a submodule from ./. except for
> the occurrence in create_lib_submodule_repo as there it seems we craft
> a repository deliberately for both inside as well as outside use.

But isn't the point of this change that use of ./. cannot be mimicking any real-world use, hence pointless for the purpose of really testing the components of the system? If "we craft deliberately for both inside and outside use" indeed _IS_ a good thing, then perhaps use of ./. has practical real-world use---if not, wouldn't we want to fix the scripts that include the lib-submodule-repo helper not to test such an unrealistic layout?