view tests/test-simplekeyvaluefile.py @ 44985:1ca0047fd7e1

absorb: preserve changesets which were already empty

Most commands in Mercurial (commit, rebase, absorb itself) don’t create empty
changesets or drop them if they become empty. If there’s a changeset that’s
empty, it must be a deliberate choice of the user. At least it shouldn’t be
absorb’s responsibility to prune them. The fact that changesets that became
empty during absorb are pruned, is unaffected by this.

This case was found while writing patches which make it possible to configure
absorb and rebase to not drop empty changesets. Even without having such config
set, I think it’s valuable to preserve changesets which were already empty.

from __future__ import absolute_import

import unittest
import silenttestrunner

from mercurial import (
    error,
    scmutil,
)


class mockfile(object):
    def __init__(self, name, fs):
        self.name = name
        self.fs = fs

    def __enter__(self):
        return self

    def __exit__(self, *args, **kwargs):
        pass

    def write(self, text):
        self.fs.contents[self.name] = text

    def read(self):
        return self.fs.contents[self.name]


class mockvfs(object):
    def __init__(self):
        self.contents = {}

    def read(self, path):
        return mockfile(path, self).read()

    def readlines(self, path):
        # lines need to contain the trailing '\n' to mock the real readlines
        return [l for l in mockfile(path, self).read().splitlines(True)]

    def __call__(self, path, mode, atomictemp):
        return mockfile(path, self)


class testsimplekeyvaluefile(unittest.TestCase):
    def setUp(self):
        self.vfs = mockvfs()

    def testbasicwritingiandreading(self):
        dw = {b'key1': b'value1', b'Key2': b'value2'}
        scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(dw)
        self.assertEqual(
            sorted(self.vfs.read(b'kvfile').split(b'\n')),
            [b'', b'Key2=value2', b'key1=value1'],
        )
        dr = scmutil.simplekeyvaluefile(self.vfs, b'kvfile').read()
        self.assertEqual(dr, dw)

    if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
        # Python 3.7 deprecates the regex*p* version, but 2.7 lacks
        # the regex version.
        assertRaisesRegex = (  # camelcase-required
            unittest.TestCase.assertRaisesRegexp
        )

    def testinvalidkeys(self):
        d = {b'0key1': b'value1', b'Key2': b'value2'}
        with self.assertRaisesRegex(
            error.ProgrammingError, 'keys must start with a letter.*'
        ):
            scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)

        d = {b'key1@': b'value1', b'Key2': b'value2'}
        with self.assertRaisesRegex(error.ProgrammingError, 'invalid key.*'):
            scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)

    def testinvalidvalues(self):
        d = {b'key1': b'value1', b'Key2': b'value2\n'}
        with self.assertRaisesRegex(error.ProgrammingError, 'invalid val.*'):
            scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)

    def testcorruptedfile(self):
        self.vfs.contents[b'badfile'] = b'ababagalamaga\n'
        with self.assertRaisesRegex(
            error.CorruptedState, 'dictionary.*element.*'
        ):
            scmutil.simplekeyvaluefile(self.vfs, b'badfile').read()

    def testfirstline(self):
        dw = {b'key1': b'value1'}
        scmutil.simplekeyvaluefile(self.vfs, b'fl').write(dw, firstline=b'1.0')
        self.assertEqual(self.vfs.read(b'fl'), b'1.0\nkey1=value1\n')
        dr = scmutil.simplekeyvaluefile(self.vfs, b'fl').read(
            firstlinenonkeyval=True
        )
        self.assertEqual(dr, {b'__firstline': b'1.0', b'key1': b'value1'})


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