Re: [PATCH v4 7/9] t3437: test script for fixup [-C|-c] options in interactive rebase

Hi Eric

Thanks for taking such a close look at this series.

On 02/02/2021 02:01, Eric Sunshine wrote:

On Fri, Jan 29, 2021 at 1:25 PM Charvi Mendiratta [off-list ref] wrote:
[...]

quoted

+       ORIG_AUTHOR_NAME="$GIT_AUTHOR_NAME" &&
+       ORIG_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" &&
+       GIT_AUTHOR_NAME="Amend Author" &&
+       GIT_AUTHOR_EMAIL="amend@example.com" &&
+       test_commit "$(cat message)" A A1 A1 &&
+       test_commit A2 A &&
+       test_commit A3 A &&
+       GIT_AUTHOR_NAME="$ORIG_AUTHOR_NAME" &&
+       GIT_AUTHOR_EMAIL="$ORIG_AUTHOR_EMAIL" &&

Are the timestamps of these commits meaningful in this context?

I think we want to ensure that the timestamp of the commits created with the different author are different from the previous commits. We ought to be checking that the author date of the rebased commit matches the author date of the original commit and not the author date of the fixup commit created with the different author.

If not, another way to do this would be to assign the new author
name/email values in a subshell so that the values do not need to be
restored manually. For instance:

     (
         GIT_AUTHOR_NAME="Amend Author" &&
         GIT_AUTHOR_EMAIL="amend@example.com" &&
         test_commit "$(cat message)" A A1 A1 &&
         test_commit A2 A &&
         test_commit A3 A
     ) &&

It's a matter of taste whether or not that is preferable, though.

quoted

+       echo B1 >B &&
+       test_tick &&
+       git commit --fixup=HEAD -a &&
+       test_tick &&

Same question about whether the commit timestamps have any
significance in these tests.

Same answer as above - we want different author dates so we can check the original author date is not modified.

I'm not sure that we are actually checking the dates yet though it looks like we only check the author name and email at the moment.

Best Wishes

Phillip

If not, then these test_tick() calls
mislead the reader into thinking that the timestamps are significant,
thus it would make sense to drop them.

quoted

+test_expect_success 'simple fixup -C works' '
+       test_when_finished "test_might_fail git rebase --abort" &&
+       git checkout --detach A2 &&
+       FAKE_LINES="1 fixup_-C 2" git rebase -i B &&

I see that you mirrored the implementation of FAKE_LINES handling of
"exec" here for "fixup", but the cases are quite different. The
argument to "exec" is arbitrary and can have any number of spaces
embedded in it, which conflicts with the meaning of spaces in
FAKE_LINES, which separate the individual commands in FAKE_LINES.
Consequently, "_" was chosen as a placeholder in "exec" to mean
"space".

However, "fixup" is a very different beast. Its arguments are not
arbitrary at all, so there isn't a good reason to mirror the choice of
"_" to represent a space, which leads to rather unsightly tokens such
as "fixup_-C". It would work just as well to use simpler tokens such
as "fixup-C" and "fixup-c", in which case t/lib-rebase.sh might parse
them like this (note that I also dropped `g` from the `sed` action):

     fixup-*)
         action=$(echo "$line" | sed 's/-/ -/');;

In fact, the recognized set of options following "fixup" is so small,
that you could even get by with simpler tokens "fixupC" and "fixupc":

     fixupC)
         action="fixup -C";;
     fixupc)
         actions="fixup -c";;

Though it's subjective whether or not "fixupC" and "fixupc" are nicer
than "fixup-C" and "fixup-c", respectively.

quoted

+test_expect_success 'fixup -C removes amend! from message' '
+       test_when_finished "test_might_fail git rebase --abort" &&
+       git checkout --detach A1 &&
+       FAKE_LINES="1 fixup_-C 2" git rebase -i A &&
+       test_cmp_rev HEAD^ A &&
+       test_cmp_rev HEAD^{tree} A1^{tree} &&
+       test_commit_message HEAD expected-message &&
+       get_author HEAD >actual-author &&
+       test_cmp expected-author actual-author
+'

This test seems out of place. I would expect to see it added in the
patch which adds "amend!" functionality.

Alternatively, if the intention really is to support "amend!" this
early in the series in [6/9], then the commit message of [6/9] should
talk about it.

quoted

+test_expect_success 'fixup -C with conflicts gives correct message' '
+       test_when_finished "test_might_fail git rebase --abort" &&

Is there a reason this isn't written as:

     test_when_finished "reset_rebase" &&

which is more common? Is there something non-obvious which makes
reset_rebase() inappropriate in these tests?

quoted

+       git checkout --detach A1 &&
+       test_must_fail env FAKE_LINES="1 fixup_-C 2" git rebase -i conflicts &&
+       git checkout --theirs -- A &&
+       git add A &&
+       FAKE_COMMIT_AMEND=edited git rebase --continue &&
+       test_cmp_rev HEAD^ conflicts &&
+       test_cmp_rev HEAD^{tree} A1^{tree} &&
+       test_write_lines "" edited >>expected-message &&

It feels clunky and fragile for this test to be changing
"expected-message" which was created in the "setup" test and used
unaltered up to this point. If the content of "expected-message" is
really going to change from test to test (as I see it changes again in
a later test), then it would be easier to reason about the behavior if
each test gives "expected-message" the precise content it should have
in that local context. As it is currently implemented, it's too
difficult to follow along and remember the value of "expected-message"
from test to test. It also makes it difficult to extend tests or add
new tests in between existing tests without negatively impacting other
tests. If each test sets up "expected-message" to the precise content
needed by the test, then both those problems go away.

quoted

+test_expect_success 'multiple fixup -c opens editor once' '
+       test_when_finished "test_might_fail git rebase --abort" &&
+       git checkout --detach A3 &&
+       base=$(git rev-parse HEAD~4) &&
+       FAKE_COMMIT_MESSAGE="Modified-A3" \
+               FAKE_LINES="1 fixup_-C 2 fixup_-c 3 fixup_-c 4" \
+               EXPECT_HEADER_COUNT=4 \
+               git rebase -i $base &&
+       test_cmp_rev $base HEAD^ &&
+       test 1 = $(git show | grep Modified-A3 | wc -l)
+'

These days, we would phrase the last part of the test as:

     git show > raw &&
     grep Modified-A3 raw >out &&
     test_line_count = 1 out