Re: [RFC PATCH 4/6] tests: use `git submodule add` and fix expected diffs

Junio C Hamano [off-list ref] writes:

Calvin Wan [off-list ref] writes:

quoted

From: Josh Steadmon <redacted>

This commit continues the previous work of updating the test suite to
use `git submodule add` to create submodules instead of using `git add`
to include embedded repositories. Specifically, in this commit we update
test cases where expected diffs must change due to the presence of a
.gitmodules file.

Good that these "same" tasks are split into two steps, ones that
don't notice the additional presence of .gitmodules (i.e. the
previous step) and the result that do.

Strictly speaking, gitlink support in the index and trees does not
have to be used to record submodules, and changing all "git add" to
"git submodule add" is somewhat a sad change that closes the door to
those folks who want to use the mechanism for implementing "better
submodules" that do not depend on a separate .gitmodules files, for
example.  To leave the door open, "git add" may need to learn an
overriding mechanism allow adding a gitlink to the index without
anything else.  And then this step could use "git add -f" (or
whategver the overriding mechanism) instead of "git submodule add",
without changing the expected diff output.

Would such a tweak make this step better?  I dunno.

The other side of the coin is that the tests that were touched by
the previous step were not testing half of what "submodule add" is
doing.  Not all the "let's add submodule here" test may not have to
verify the resulting .gitmodules file (e.g. ones that want to see
the low-level diff machinery works correctly by taking output from
"git diff --cached --raw" would be primarily interested in what
happens to the index and not to .gitmodules at all), but some of
them should.  A rough rule of thumb might be that the tests that are
about "submodules" should care what ".gitmodules" has, while the
tests tare are about "gitlink" should not.  It might even make sense
to use "add -f" (or whatever override to allow adding a gitlink only
to the index without touching .gitmodules and other things), not
"submodule add", for the latter class of tests.

Thanks.