tests/test-mdiff.py

nodemap: add a test about racy commit during stream clone

That test show that the resulting client nodemap is different from the server
one. This happens because the server one transferred a corrupted node map. The
data file match the pre-commit content while the docket has post commit content.
As the result the nodemap was detected invalid and recomputed.

When running without the rust implementation, the code is also generating a new
datafile unconditionally, This mean the older file is no longer there are
transfer time, resulting in a crash.

We will fix this issue later, but we start with writing tests highlighting the
issue.

Differential Revision: https://phab.mercurial-scm.org/D10479

from __future__ import absolute_import
from __future__ import print_function

import unittest

from mercurial import mdiff


class splitnewlinesTests(unittest.TestCase):
    def test_splitnewlines(self):
        cases = {
            b'a\nb\nc\n': [b'a\n', b'b\n', b'c\n'],
            b'a\nb\nc': [b'a\n', b'b\n', b'c'],
            b'a\nb\nc\n\n': [b'a\n', b'b\n', b'c\n', b'\n'],
            b'': [],
            b'abcabc': [b'abcabc'],
        }
        for inp, want in cases.items():
            self.assertEqual(mdiff.splitnewlines(inp), want)


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)