contrib/python-zstandard/tests/test_buffer_util.py

scmutil: make cleanupnodes optionally also fix the phase

We have had multiple bugs where the phase wasn't correctly carried
forward to a rewritten changeset (for example: phabricator, split,
evolve, fix). Handling the phase update in cleanupnodes() makes it
less likely to happen again, especially once we have made it fix the
phase by default (perhaps in the next release cycle).

This patch also updates all applicable callers so we get some testing
of it.

Note that rebase and histedit can't be fixed yet because they call
cleanupnodes() only at the end and the phase may have been changed by
the user when the rebase/histedit was interrupted (due to merge
conflicts). I think we should make them write one commit at a time (as
it already does), along with associated obsmarkers, bookmark moves,
etc. When that's done, we can switch them over to cleanupnodes().

Differential Revision: https://phab.mercurial-scm.org/D3818

import struct
import unittest

import zstandard as zstd

ss = struct.Struct('=QQ')


class TestBufferWithSegments(unittest.TestCase):
    def test_arguments(self):
        with self.assertRaises(TypeError):
            zstd.BufferWithSegments()

        with self.assertRaises(TypeError):
            zstd.BufferWithSegments(b'foo')

        # Segments data should be a multiple of 16.
        with self.assertRaisesRegexp(ValueError, 'segments array size is not a multiple of 16'):
            zstd.BufferWithSegments(b'foo', b'\x00\x00')

    def test_invalid_offset(self):
        with self.assertRaisesRegexp(ValueError, 'offset within segments array references memory'):
            zstd.BufferWithSegments(b'foo', ss.pack(0, 4))

    def test_invalid_getitem(self):
        b = zstd.BufferWithSegments(b'foo', ss.pack(0, 3))

        with self.assertRaisesRegexp(IndexError, 'offset must be non-negative'):
            test = b[-10]

        with self.assertRaisesRegexp(IndexError, 'offset must be less than 1'):
            test = b[1]

        with self.assertRaisesRegexp(IndexError, 'offset must be less than 1'):
            test = b[2]

    def test_single(self):
        b = zstd.BufferWithSegments(b'foo', ss.pack(0, 3))
        self.assertEqual(len(b), 1)
        self.assertEqual(b.size, 3)
        self.assertEqual(b.tobytes(), b'foo')

        self.assertEqual(len(b[0]), 3)
        self.assertEqual(b[0].offset, 0)
        self.assertEqual(b[0].tobytes(), b'foo')

    def test_multiple(self):
        b = zstd.BufferWithSegments(b'foofooxfooxy', b''.join([ss.pack(0, 3),
                                                               ss.pack(3, 4),
                                                               ss.pack(7, 5)]))
        self.assertEqual(len(b), 3)
        self.assertEqual(b.size, 12)
        self.assertEqual(b.tobytes(), b'foofooxfooxy')

        self.assertEqual(b[0].tobytes(), b'foo')
        self.assertEqual(b[1].tobytes(), b'foox')
        self.assertEqual(b[2].tobytes(), b'fooxy')


class TestBufferWithSegmentsCollection(unittest.TestCase):
    def test_empty_constructor(self):
        with self.assertRaisesRegexp(ValueError, 'must pass at least 1 argument'):
            zstd.BufferWithSegmentsCollection()

    def test_argument_validation(self):
        with self.assertRaisesRegexp(TypeError, 'arguments must be BufferWithSegments'):
            zstd.BufferWithSegmentsCollection(None)

        with self.assertRaisesRegexp(TypeError, 'arguments must be BufferWithSegments'):
            zstd.BufferWithSegmentsCollection(zstd.BufferWithSegments(b'foo', ss.pack(0, 3)),
                                              None)

        with self.assertRaisesRegexp(ValueError, 'ZstdBufferWithSegments cannot be empty'):
            zstd.BufferWithSegmentsCollection(zstd.BufferWithSegments(b'', b''))

    def test_length(self):
        b1 = zstd.BufferWithSegments(b'foo', ss.pack(0, 3))
        b2 = zstd.BufferWithSegments(b'barbaz', b''.join([ss.pack(0, 3),
                                                          ss.pack(3, 3)]))

        c = zstd.BufferWithSegmentsCollection(b1)
        self.assertEqual(len(c), 1)
        self.assertEqual(c.size(), 3)

        c = zstd.BufferWithSegmentsCollection(b2)
        self.assertEqual(len(c), 2)
        self.assertEqual(c.size(), 6)

        c = zstd.BufferWithSegmentsCollection(b1, b2)
        self.assertEqual(len(c), 3)
        self.assertEqual(c.size(), 9)

    def test_getitem(self):
        b1 = zstd.BufferWithSegments(b'foo', ss.pack(0, 3))
        b2 = zstd.BufferWithSegments(b'barbaz', b''.join([ss.pack(0, 3),
                                                          ss.pack(3, 3)]))

        c = zstd.BufferWithSegmentsCollection(b1, b2)

        with self.assertRaisesRegexp(IndexError, 'offset must be less than 3'):
            c[3]

        with self.assertRaisesRegexp(IndexError, 'offset must be less than 3'):
            c[4]

        self.assertEqual(c[0].tobytes(), b'foo')
        self.assertEqual(c[1].tobytes(), b'bar')
        self.assertEqual(c[2].tobytes(), b'baz')