Re: [PATCH] for-each-ref: add %(upstream:gone) to mark missing refs

From: Jeff King <peff@peff.net>
Date: Aug 24, 2016, 18:05 UTC
Message-ID: <20160824180541.jrliwgkrqu2siywd@sigill.intra.peff.net>
In-Reply-To: <20160819215023.10770-1-oystwa@gmail.com>

On Fri, Aug 19, 2016 at 11:50:23PM +0200, Øystein Walle wrote:

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> git branch -vv will show "gone" next to a remote tracking branch if it
> does not exist. for-each-ref is suitable for parsing but had no way of
> showing this information.
> 
> This introduces "%(upstream:gone)" to display "gone" in the formatted
> output if the ref does not exist or an empty string otherwise, analogous
> to git branch -vv.

Hmm. So this sounds like the minimum thing to implement "branch -vv" output, but it feels sort of weirdly non-orthogonal. I guess you'd say:

  %(upstream:track)%(upstream:gone)

and assume that only one of them will show any data.

I almost wonder if %(upstream:track) should just output some specific token for the "gone" case, which matches what "branch -vv" does.

(I'm also not sure we can match "branch -vv" exactly here anyway, as it looks like "[%(upstream): %(upstream:track)"], but our "%(upstream:track)" uses its own brackets.)

I suppose that is a backwards-incompatible change for "%(upstream:track)", but I'm not sure how much we have promised about its format. The error cases seem totally undocumented.

Show 5 quoted lines

> ---
>  Documentation/git-for-each-ref.txt |  5 +++--
>  ref-filter.c                       | 10 +++++++++-
>  t/t6300-for-each-ref.sh            | 12 ++++++++++++
>  3 files changed, 24 insertions(+), 3 deletions(-)

The code itself looks OK to me (assuming we want upstream:gone as the interface), with a few minor nits in the test:

> +test_expect_success 'Check that :gone produces expected results' '
> +	cat >expected <<-\EOF &&
> +gone
> +	EOF

The "<<-" will strip leading tabs, meaning you can indent "gone" here to match the rest of the test.

> +	test_when_finished "git config branch.master.merge refs/heads/master" &&
> +	git config branch.master.merge refs/heads/does-not-exist &&

I thought this could be test_config, but it is not clever enough to restore an old value, only to remove a value we just added. So this is probably the best solution.

Show 5 quoted lines

> +	git for-each-ref \
> +		--format="%(upstream:gone)" \
> +		refs/heads >actual &&
> +	test_cmp expected actual
> +'

This tests only that we show "gone"; do you want to add a second branch and make sure that it shows nothing? Maybe you could even use a new branch name, which makes test_config applicable again:

  cat >expected <<-\EOF &&
  master 
  no-upstream gone
  EOF
  git branch refs/heads/no-upstream &&
  test_config branch.no-upstream.remote . &&
  test_config branch.no-upstream.merge refs/heads/does-not-exist &&
  git for-each-ref --format="%(refname:short) %(upstream:gone)" >actual &&
  test_cmp expected actual

-Peff