~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 by Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Test reweave code.

Reweave takes two weaves containing a partial view of history and combines

them into a single weave containing all the information.  This can include 

 - versions recorded in only one file

 - versions with different (but not contradictory) lists of parent 

   revisions

It is an error if either of these conditions occur:

 - contradictory ancestry graphs, e.g.

   - v1 is an ancestor of v2 in one weave, and vice versa in the other

   - different text for any version 

"""

import os

import sys

from bzrlib.tests import TestCase

from bzrlib.weave import Weave, reweave

from bzrlib.errors import WeaveParentMismatch

class TestReweave(TestCase):

    def test_reweave_add_parents(self):

        """Reweave inserting new parents

        The new version must have the right parent list and must identify

        lines originating in another parent.

        """

        w1 = Weave('w1')

        w2 = Weave('w2')

        w1.add('v-1', [], ['line 1\n'])

        w2.add('v-2', [], ['line 2\n'])

        w1.add('v-3', ['v-1'], ['line 1\n'])

        w2.add('v-3', ['v-2'], ['line 1\n'])

        w3 = reweave(w1, w2)

        self.assertEqual(sorted(w3.names()),

                         'v-1 v-2 v-3'.split())

        self.assertEqualDiff(w3.get_text('v-3'),

                'line 1\n')

        self.assertEqual(sorted(w3.parent_names('v-3')),

                ['v-1', 'v-2'])

        ann = list(w3.annotate('v-3'))

        self.assertEqual(len(ann), 1)

        self.assertEqual(w3.idx_to_name(ann[0][0]), 'v-1')

        self.assertEqual(ann[0][1], 'line 1\n')

    def build_weave1(self):

        weave1 = Weave()

        self.lines1 = ['hello\n']

        self.lines3 = ['hello\n', 'cruel\n', 'world\n']

        weave1.add('v1', [], self.lines1)

        weave1.add('v2', [0], ['hello\n', 'world\n'])

        weave1.add('v3', [1], self.lines3)

        return weave1

    def test_reweave_with_empty(self):

        """Reweave adding empty weave"""

        wb = Weave()

        w1 = self.build_weave1()

        wr = reweave(w1, wb)

        eq = self.assertEquals

        eq(sorted(wr.iter_names()), ['v1', 'v2', 'v3'])

        eq(wr.get_lines('v3'), ['hello\n', 'cruel\n', 'world\n'])

        self.assertEquals(wr, w1)

    def test_join_with_ghosts_raises_parent_mismatch(self):

        """Join weave traps parent mismatch"""

        wa = self.build_weave1()

        wb = Weave()

        wb.add('x1', [], ['line from x1\n'])

        wb.add('v1', [], ['hello\n'])

        wb.add('v2', ['v1', 'x1'], ['hello\n', 'world\n'])

        self.assertRaises(WeaveParentMismatch, wa.join, wb)

    def test_reweave_with_ghosts(self):

        """Join that inserts parents of an existing revision.

        This can happen when merging from another branch who

        knows about revisions the destination does not.  In 

        this test the second weave knows of an additional parent of 

        v2.  Any revisions which are in common still have to have the 

        same text.

        """

        w1 = self.build_weave1()

        wa = w1.copy()

        wb = Weave()

        wb.add('x1', [], ['line from x1\n'])

        wb.add('v1', [], ['hello\n'])

        wb.add('v2', ['v1', 'x1'], ['hello\n', 'world\n'])

        wc = reweave(wa, wb)

        eq = self.assertEquals

        eq(sorted(wc.iter_names()), ['v1', 'v2', 'v3', 'x1',])

        eq(wc.get_text('x1'), 'line from x1\n')

        eq(wc.get_lines('v2'), ['hello\n', 'world\n'])

        eq(wc.parent_names('v2'), ['v1', 'x1'])

        w1.reweave(wb)

        self.assertEquals(wc, w1)

    def build_empty_weave(self, *pattern):

        w = Weave()

        for version, parents in pattern:

            w.add(version, parents, [])

        return w

    def test_reweave_reorder(self):

        """Reweave requiring reordering of versions.

        Weaves must be stored such that parents come before children.  When

        reweaving, we may add new parents to some children, but it is required

        that there must be *some* valid order that can be found, otherwise the

        ancestries are contradictory.  (For the specific case of inserting

        ghost revisions there will be no disagreement, only partial knowledge

        of the history.)

        Note that the weaves are only partially ordered: when there are two

        versions where neither is an ancestor of the other the order in which

        they occur is unconstrained.  When we reweave those versions into

        another weave, they may become more constrained and it may be

        necessary to change their order.

        One simple case of this is 

        w1: (c[], a[], b[a])

        w2: (b[], c[b], a[])

        We need to recognize that the final weave must show the ordering

        a[], b[a], c[b].  The version that must be first in the result is 

        not first in either of the input weaves.

        """

        w1 = self.build_empty_weave(('c', []), ('a', []), ('b', ['a']))

        w2 = self.build_empty_weave(('b', []), ('c', ['b']), ('a', []))

        w3 = reweave(w1, w2)