tests/test-mdiff.py

tests: stabilize `test-split-legacy-inline-changelog.t` on Windows

The `tar` command is unable to process "C:\path\to\foo.tar" style paths, which
is how `$TESTDIR` is constructed.  It also didn't work with
`$TESTDIR_FORWARD_SLASH`- both failed with:

    tar: Cannot connect to C: resolve failed
    [128]

But `cat` can handle it if the path is quoted, and `tar` can read from stdin.

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__)