view tests/test-bdiff.py @ 42920:a50661567f83

uncommit: drop the hyphen from --current-user and --current-date

I didn't pay enough attention to these long forms- graft, amend and MQ already
use the old style naming.  It's probably more important to be consistent than
modern.  The hypenated style came from evolve.

Yuya mentioned this naming discrepancy in 4145fd3569c3, but it didn't attract
any discussion[1].  There's also a bit of inconsistency in that the default
parameter for `currentdate` is `False` for graft, and `None` for the rest.

[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2019-January/126767.html

Differential Revision: https://phab.mercurial-scm.org/D6841

from __future__ import absolute_import, print_function
import collections
import struct
import unittest

from mercurial import (
    mdiff,
)

class diffreplace(
    collections.namedtuple('diffreplace', 'start end from_ to')):
    def __repr__(self):
        return 'diffreplace(%r, %r, %r, %r)' % self

class BdiffTests(unittest.TestCase):

    def assert_bdiff_applies(self, a, b):
        d = mdiff.textdiff(a, b)
        c = a
        if d:
            c = mdiff.patches(a, [d])
        self.assertEqual(
            c, b, ("bad diff+patch result from\n  %r to\n  "
                   "%r: \nbdiff: %r\npatched: %r" % (a, b, d, c[:200])))

    def assert_bdiff(self, a, b):
        self.assert_bdiff_applies(a, b)
        self.assert_bdiff_applies(b, a)

    def test_bdiff_basic(self):
        cases = [
            (b"a\nc\n\n\n\n", b"a\nb\n\n\n"),
            (b"a\nb\nc\n", b"a\nc\n"),
            (b"", b""),
            (b"a\nb\nc", b"a\nb\nc"),
            (b"a\nb\nc\nd\n", b"a\nd\n"),
            (b"a\nb\nc\nd\n", b"a\nc\ne\n"),
            (b"a\nb\nc\n", b"a\nc\n"),
            (b"a\n", b"c\na\nb\n"),
            (b"a\n", b""),
            (b"a\n", b"b\nc\n"),
            (b"a\n", b"c\na\n"),
            (b"", b"adjfkjdjksdhfksj"),
            (b"", b"ab"),
            (b"", b"abc"),
            (b"a", b"a"),
            (b"ab", b"ab"),
            (b"abc", b"abc"),
            (b"a\n", b"a\n"),
            (b"a\nb", b"a\nb"),
        ]
        for a, b in cases:
            self.assert_bdiff(a, b)

    def showdiff(self, a, b):
        bin = mdiff.textdiff(a, b)
        pos = 0
        q = 0
        actions = []
        while pos < len(bin):
            p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12])
            pos += 12
            if p1:
                actions.append(a[q:p1])
            actions.append(diffreplace(p1, p2, a[p1:p2], bin[pos:pos + l]))
            pos += l
            q = p2
        if q < len(a):
            actions.append(a[q:])
        return actions

    def test_issue1295(self):
        cases = [
            (b"x\n\nx\n\nx\n\nx\n\nz\n", b"x\n\nx\n\ny\n\nx\n\nx\n\nz\n",
             [b'x\n\nx\n\n',
              diffreplace(6, 6, b'', b'y\n\n'),
              b'x\n\nx\n\nz\n']),
            (b"x\n\nx\n\nx\n\nx\n\nz\n", b"x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n",
             [b'x\n\nx\n\n',
              diffreplace(6, 6, b'', b'y\n\n'),
              b'x\n\n',
              diffreplace(9, 9, b'', b'y\n\n'),
              b'x\n\nz\n']),
        ]
        for old, new, want in cases:
            self.assertEqual(self.showdiff(old, new), want)

    def test_issue1295_varies_on_pure(self):
            # we should pick up abbbc. rather than bc.de as the longest match
        got = self.showdiff(b"a\nb\nb\nb\nc\n.\nd\ne\n.\nf\n",
                            b"a\nb\nb\na\nb\nb\nb\nc\n.\nb\nc\n.\nd\ne\nf\n")
        want_c = [b'a\nb\nb\n',
                  diffreplace(6, 6, b'', b'a\nb\nb\nb\nc\n.\n'),
                  b'b\nc\n.\nd\ne\n',
                  diffreplace(16, 18, b'.\n', b''),
                  b'f\n']
        want_pure = [diffreplace(0, 0, b'', b'a\nb\nb\n'),
                     b'a\nb\nb\nb\nc\n.\n',
                     diffreplace(12, 12, b'', b'b\nc\n.\n'),
                     b'd\ne\n',
                     diffreplace(16, 18, b'.\n', b''), b'f\n']
        self.assertTrue(got in (want_c, want_pure),
                        'got: %r, wanted either %r or %r' % (
                            got, want_c, want_pure))

    def test_fixws(self):
        cases = [
            (b" \ta\r b\t\n", b"ab\n", 1),
            (b" \ta\r b\t\n", b" a b\n", 0),
            (b"", b"", 1),
            (b"", b"", 0),
        ]
        for a, b, allws in cases:
            c = mdiff.fixws(a, allws)
            self.assertEqual(
                c, b, 'fixws(%r) want %r got %r (allws=%r)' % (a, b, c, allws))

    def test_nice_diff_for_trivial_change(self):
        self.assertEqual(self.showdiff(
            b''.join(b'<%d\n-\n' % i for i in range(5)),
            b''.join(b'>%d\n-\n' % i for i in range(5))),
                         [diffreplace(0, 3, b'<0\n', b'>0\n'),
                          b'-\n',
                          diffreplace(5, 8, b'<1\n', b'>1\n'),
                          b'-\n',
                          diffreplace(10, 13, b'<2\n', b'>2\n'),
                          b'-\n',
                          diffreplace(15, 18, b'<3\n', b'>3\n'),
                          b'-\n',
                          diffreplace(20, 23, b'<4\n', b'>4\n'),
                          b'-\n'])

    def test_prefer_appending(self):
        # 1 line to 3 lines
        self.assertEqual(self.showdiff(b'a\n', b'a\n' * 3),
                         [b'a\n', diffreplace(2, 2, b'', b'a\na\n')])
        # 1 line to 5 lines
        self.assertEqual(self.showdiff(b'a\n', b'a\n' * 5),
                         [b'a\n', diffreplace(2, 2, b'', b'a\na\na\na\n')])

    def test_prefer_removing_trailing(self):
        # 3 lines to 1 line
        self.assertEqual(self.showdiff(b'a\n' * 3, b'a\n'),
                         [b'a\n', diffreplace(2, 6, b'a\na\n', b'')])
        # 5 lines to 1 line
        self.assertEqual(self.showdiff(b'a\n' * 5, b'a\n'),
                         [b'a\n', diffreplace(2, 10, b'a\na\na\na\n', b'')])

if __name__ == '__main__':
    import silenttestrunner
    silenttestrunner.main(__name__)