view tests/test-hashutil.py @ 45121:b6269741ed42

config: add option to control creation of empty successors during rewrite

The default for many history-rewriting commands (e.g. rebase and absorb) is
that changesets which would become empty are not created in the target branch.
This makes sense if the source branch consists of small fix-up changes. For
more advanced workflows that make heavy use of history-editing to create
curated patch series, dropping empty changesets is not as important or even
undesirable.

Some users want to keep the meta-history, e.g. to make finding comments in a
code review tool easier or to avoid that divergent bookmarks are created. For
that, obsmarkers from the (to-be) empty changeset to the changeset(s) that
already made the changes should be added. If a to-be empty changeset is pruned
without a successor, adding the obsmarkers is hard because the changeset has to
be found within the hidden part of the history.

If rebasing in TortoiseHg, it’s easy to miss the fact that the to-be empty
changeset was pruned. An empty changeset will function as a reminder that
obsmarkers should be added.

Martin von Zweigbergk mentioned another advantage. Stripping the successor will
de-obsolete the predecessor. If no (empty) successor is created, this won’t be
possible.

In the future, we may want to consider other behaviors, like e.g. creating the
empty successor, but pruning it right away. Therefore this configuration
accepts 'skip' and 'keep' instead of being a boolean configuration.

# Tests to ensure that sha1dc.sha1 is exactly a drop-in for
# hashlib.sha1 for our needs.
from __future__ import absolute_import

import hashlib
import unittest

import silenttestrunner

try:
    from mercurial.thirdparty import sha1dc
except ImportError:
    sha1dc = None


class hashertestsbase(object):
    def test_basic_hash(self):
        h = self.hasher()
        h.update(b'foo')
        self.assertEqual(
            '0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33', h.hexdigest()
        )
        h.update(b'bar')
        self.assertEqual(
            '8843d7f92416211de9ebb963ff4ce28125932878', h.hexdigest()
        )

    def test_copy_hasher(self):
        h = self.hasher()
        h.update(b'foo')
        h2 = h.copy()
        h.update(b'baz')
        h2.update(b'bar')
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )
        self.assertEqual(
            '8843d7f92416211de9ebb963ff4ce28125932878', h2.hexdigest()
        )

    def test_init_hasher(self):
        h = self.hasher(b'initial string')
        self.assertEqual(
            b'\xc9y|n\x1f3S\xa4:\xbaJ\xca,\xc1\x1a\x9e\xb8\xd8\xdd\x86',
            h.digest(),
        )

    def test_bytes_like_types(self):
        h = self.hasher()
        h.update(bytearray(b'foo'))
        h.update(memoryview(b'baz'))
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )

        h = self.hasher(bytearray(b'foo'))
        h.update(b'baz')
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )

        h = self.hasher(memoryview(b'foo'))
        h.update(b'baz')
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )


class hashlibtests(unittest.TestCase, hashertestsbase):
    hasher = hashlib.sha1


if sha1dc:

    class sha1dctests(unittest.TestCase, hashertestsbase):
        hasher = sha1dc.sha1


if __name__ == '__main__':
    silenttestrunner.main(__name__)