tests/test-simplekeyvaluefile.py

copies: add config option for writing copy metadata to file and/or changset

This introduces a config option that lets you choose to write copy
metadata to the changeset extras instead of to filelog. There's also
an option to write it to both places. I imagine that may possibly be
useful when transitioning an existing repo.

The copy metadata is stored as two fields in extras: one for copies
since p1 and one for copies since p2.

I may need to add more information later in order to make copy tracing
faster. Specifically, I'm thinking out recording which files were
added or removed so that copies._chaincopies() doesn't have to look at
the manifest for that. But that would just be an optimization and that
can be added once we know if it's necessary.

I have also considered saving space by using replacing the destination
file path by an index into the "files" list, but that can also be
changed later (but before the feature is ready to release).

Differential Revision: https://phab.mercurial-scm.org/D6183

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__)