Re: Drastic jump in the time required for the test suite

From: Stefan Beller <sbeller@google.com>
Date: Oct 20, 2016, 19:54 UTC
Message-ID: <CAGZ79kZpj5xXHmnA+JfLKdGmgzp7Mut1OsKMOeowpw8m1+aKGA@mail.gmail.com>
In-Reply-To: <alpine.DEB.2.20.1610201218060.3264@virtualbox>

On Thu, Oct 20, 2016 at 3:50 AM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:

Show 8 quoted lines

> Hi peff,
>
> On Wed, 19 Oct 2016, Jeff King wrote:
>
>> On Wed, Oct 19, 2016 at 10:32:12AM -0700, Junio C Hamano wrote:
>>
>> > > Maybe we should start optimizing the tests...
>> >

Maybe we should stop introducing un-optimized tests. For other reasons I just stumbled upon t7064 (porcelain V2 output for git status)

This is how an arbitrary test looks like:

test_expect_success 'staged changes in added submodule (AM S.M.)' '
    (    cd super_repo &&
        ## stage the changes in the submodule.
        (    cd sub1 &&
            git add file_in_sub
        ) &&

        HMOD=$(git hash-object -t blob -- .gitmodules) &&
        HSUP=$(git rev-parse HEAD) &&
        HSUB=$HSUP &&

        cat >expect <<-EOF &&
        # branch.oid $HSUP
        # branch.head master
        # branch.upstream origin/master
        # branch.ab +0 -0
        1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
        1 AM S.M. 000000 160000 160000 $_z40 $HSUB sub1
        EOF

        git status --porcelain=v2 --branch --untracked-files=all >actual &&
        test_cmp expect actual
    )
'

Following "modern" Git tests I would have expected:

* heavy use of the "git -C <dir>" pattern. When applying that
  thouroughly we'd save spanning the subshells.
* no `cd` on the same line as the opening paren.
  (This is style and would derail the performance discussion)

test_expect_success 'staged changes in added submodule (AM S.M.)' '
    git -C super_repo/sub1 add file_in_sub &&
    HMOD=$(git -C super_repo hash-object -t blob -- .gitmodules) &&
    HSUP=$(git -C super_repo rev-parse HEAD) &&
    # as a comment: HSUB is equal to HSUP, because ...

    cat >expect <<-EOF &&
    # branch.oid $HSUP
    # branch.head master
    # branch.upstream origin/master
    # branch.ab +0 -0
    1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
    1 AM S.M. 000000 160000 160000 $_z40 $HSUP sub1
    EOF

    git -C super_repo status --porcelain=v2 --branch
--untracked-files=all >../actual &&
    test_cmp expect actual
'

That said I really like the idea of having a helper that would eliminate the cat for you, e.g. :

git_test_helper_equal_stdin_or_diff_and_die -C super_repo status --porcelain=v2 --branch --untracked-files=all <<-EOF 1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules 1 AM S.M. 000000 160000 160000 $_z40 $HSUP sub1 EOF

Thanks, Stefan