[PATCH] tests: add an optional test to test git-annex

Add an optional test to test git-annex. It's guarded by a new
EXTERNAL_TESTS environment variable. Running this test takes me 10
minutes.

As reported by Joey Hess in "reversion in GIT_COMMON_DIR refs path"[1]
commit f57f37e2e1 ("files-backend: remove the use of git_path()",
2017-03-26) first released as part of the 2.13.0 broke git-annex's
test suite.

This could have been spotted by us before the release by optionally
running the git-annex test suite as part of git itself. This optional
test does that. It currently fails due to the reported regression,
but, passes on the 2.12.0 release.

The git-annex revision to test can be specified with the
GIT_TEST_GIT_ANNEX_REVISION environment variable. Joey has expressed
interest in testing development versions of git against git-annex[2],
and can now test the latest revision with:

    EXTERNAL_TESTS=1 GIT_TEST_GIT_ANNEX_REVISION='@{u}' ./t9950-git-annex.sh

By default the test finds the latest git-annex release tag and tests
that, since the primary purpose is to test regressions in git which
cause git-annex to fail, not regressions in git-annex itself.

The t9* test namespace is currently full as documented in t/README. In
lie of an empty t9X for "external tools" this change claims t995* for
that purpose.

1. [ref]
   (https://public-inbox.org/git/20170516175906.hdwn4x5md7dj7fo3@kitenet.net/T/)
2. http://git-annex.branchable.com/devblog/day_459__git_bug/

Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>
---

On Tue, May 16, 2017 at 7:59 PM, Joey Hess [off-list ref] wrote:

Ævar Arnfjörð Bjarmason wrote:

quoted

On Tue, May 16, 2017 at 7:10 PM, Joey Hess [off-list ref] wrote:
I have no idea what this bug is about, but side-question: It looks
like this is git-annex's own test suite that's failing with 2.13.0, is
that right?

Yes indeed.

quoted

It would be very nice to have a test in git itself to test with
git-annex. I.e. some optional test that just pulls down the latest
git-annex release & runs its tests against the git we're building.

Thanks for annex b.t.w., I use it a lot.

If the git devs are ok with this, I certianly would be happy if such
tests were run, at least occasionally, on the git side!

I for one would run this test occasionally, and perhaps we could even
run it as part of Travis eventually (although there would be a *lot*
of Haskell deps, on my box "apt build-dep git-annex" brought in 1/2 GB
of packages).

As noted in the commit message, once this is part of git.git you can
easily set an environment variable to test the bleeding edge of git
against any arbitrary git-annex version.

 t/t9950-git-annex.sh | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100755 t/t9950-git-annex.sh

diff --git a/t/t9950-git-annex.sh b/t/t9950-git-annex.sh
new file mode 100755
index 0000000000..2cbc1f4be3
--- /dev/null
+++ b/t/t9950-git-annex.sh

@@ -0,0 +1,52 @@
+#!/bin/sh
+
+test_description='the git-annex test suite'
+. ./test-lib.sh
+
+if test -z "$EXTERNAL_TESTS"
+then
+	skip_all='skipping tests of external tools. EXTERNAL_TESTS not defined'
+	test_done
+fi
+
+if test -n "$NO_CURL"
+then
+	skip_all='skipping test, git built without http support'
+	test_done
+fi
+
+test_expect_success 'clone git-annex' '
+	git clone https://git.joeyh.name/git/git-annex.git
+'
+
+if test -n "$GIT_TEST_GIT_ANNEX_REVISION"
+then
+	test_expect_success "plan to test git-annex $GIT_TEST_GIT_ANNEX_REVISION" "
+		echo '$GIT_TEST_GIT_ANNEX_REVISION' >revision-to-test
+	"
+else
+	test_expect_success "plan to test git-annex's latest release tag" '
+		git -C git-annex tag --sort=version:refname -l "[0-9]*.[0-9]*" |
+			tail -n 1 >revision-to-test
+	'
+fi
+
+test_expect_success 'checkout $(cat revision-to-test) for testing' '
+	git -C git-annex checkout $(cat revision-to-test)
+'
+
+test_expect_success 'build git-annex (if this fails, you are likely missing its Haskell dependencies' '
+	(
+		cd git-annex &&
+		make
+	)
+'
+
+test_expect_success 'test git-annex' '
+	(
+		cd git-annex &&
+		make test
+	)
+'
+
+test_done

-- 
2.13.0.303.g4ebf302169