Re: RFC/Pull Request: Refs db backend

On Tue, Jun 23, 2015 at 12:36 PM, Junio C Hamano [off-list ref] wrote:

"If there is interest"?  Shut up and take my money ;-)

Yeah. This may be the next big thing since pack bitmap. It's even
better if it enters 'master' hand in hand with pack protocol v2, but I
think v2 needs more time.

On Tue, Jun 23, 2015 at 7:50 AM, David Turner [off-list ref] wrote:

To test this backend's correctness, I hacked test-lib.sh and
test-lib-functions.sh to run all tests under the refs backend.

Now we have two. split-index also benefits from running through full
test suite like this. I propose we make "make test" run the test suite
twice. The first run is with default configuration, no split index, no
fancy ref backend. The second run enables split-index and switches to
new backend, running through all test cases. In future we can also
enable packv4 in this second run. There won't be a third run.

When the second ref backend comes, we can switch between the two
backends using a random number generator where we control both
algorithm and seed, so that when a test fails, the user can give us
their seed and we can re-run with the same configuration.

Dozens of tests use manual ref/reflog reading/writing, or create submodules
without passing --refs-backend-type to git init.  If those tests are
changed to use the update-ref machinery or test-refs-be-db (or, in the
case of packed-refs, corrupt refs, and dumb fetch tests, are skipped),
the only remaining failing tests are the git-new-workdir tests and the
gitweb tests.

I haven't read the series, but I guess you should also add a few tests
to run on the first run, so new code is exercised a bit even if people
skip the second run.
-- 
Duy