~bzr-pqm/bzr/bzr.dev

« back to all changes in this revision

Viewing changes to bzrlib/tests/test_workingtree.py

  • Committer: Patch Queue Manager
  • Date: 2011-12-21 21:56:31 UTC
  • mfrom: (6393.2.4 907268-bazaar-DEFAULT)
  • Revision ID: pqm@pqm.ubuntu.com-20111221215631-coxvalt3phw8jaza
(vila) bzr config displays [DEFAULT] for bazaar.conf (Vincent Ladeuil)

Show diffs side-by-side

added added

removed removed

Lines of Context:
 
1
# Copyright (C) 2005-2011 Canonical Ltd
 
2
# Authors:  Robert Collins <robert.collins@canonical.com>
 
3
#
 
4
# This program is free software; you can redistribute it and/or modify
 
5
# it under the terms of the GNU General Public License as published by
 
6
# the Free Software Foundation; either version 2 of the License, or
 
7
# (at your option) any later version.
 
8
#
 
9
# This program is distributed in the hope that it will be useful,
 
10
# but WITHOUT ANY WARRANTY; without even the implied warranty of
 
11
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
12
# GNU General Public License for more details.
 
13
#
 
14
# You should have received a copy of the GNU General Public License
 
15
# along with this program; if not, write to the Free Software
 
16
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 
17
 
 
18
from bzrlib import (
 
19
    bzrdir,
 
20
    conflicts,
 
21
    errors,
 
22
    symbol_versioning,
 
23
    transport,
 
24
    workingtree,
 
25
    workingtree_3,
 
26
    workingtree_4,
 
27
    )
 
28
from bzrlib.lockdir import LockDir
 
29
from bzrlib.mutabletree import needs_tree_write_lock
 
30
from bzrlib.tests import TestCase, TestCaseWithTransport, TestSkipped
 
31
from bzrlib.workingtree import (
 
32
    TreeEntry,
 
33
    TreeDirectory,
 
34
    TreeFile,
 
35
    TreeLink,
 
36
    )
 
37
 
 
38
 
 
39
class TestTreeDirectory(TestCaseWithTransport):
 
40
 
 
41
    def test_kind_character(self):
 
42
        self.assertEqual(TreeDirectory().kind_character(), '/')
 
43
 
 
44
 
 
45
class TestTreeEntry(TestCaseWithTransport):
 
46
 
 
47
    def test_kind_character(self):
 
48
        self.assertEqual(TreeEntry().kind_character(), '???')
 
49
 
 
50
 
 
51
class TestTreeFile(TestCaseWithTransport):
 
52
 
 
53
    def test_kind_character(self):
 
54
        self.assertEqual(TreeFile().kind_character(), '')
 
55
 
 
56
 
 
57
class TestTreeLink(TestCaseWithTransport):
 
58
 
 
59
    def test_kind_character(self):
 
60
        self.assertEqual(TreeLink().kind_character(), '')
 
61
 
 
62
 
 
63
class TestDefaultFormat(TestCaseWithTransport):
 
64
 
 
65
    def test_get_set_default_format(self):
 
66
        old_format = workingtree.format_registry.get_default()
 
67
        # default is 6
 
68
        self.assertTrue(isinstance(old_format, workingtree_4.WorkingTreeFormat6))
 
69
        workingtree.format_registry.set_default(SampleTreeFormat())
 
70
        try:
 
71
            # the default branch format is used by the meta dir format
 
72
            # which is not the default bzrdir format at this point
 
73
            dir = bzrdir.BzrDirMetaFormat1().initialize('.')
 
74
            dir.create_repository()
 
75
            dir.create_branch()
 
76
            result = dir.create_workingtree()
 
77
            self.assertEqual(result, 'A tree')
 
78
        finally:
 
79
            workingtree.format_registry.set_default(old_format)
 
80
        self.assertEqual(old_format, workingtree.format_registry.get_default())
 
81
 
 
82
    def test_from_string(self):
 
83
        self.assertIsInstance(
 
84
            SampleTreeFormat.from_string("Sample tree format."),
 
85
            SampleTreeFormat)
 
86
        self.assertRaises(ValueError,
 
87
            SampleTreeFormat.from_string, "Different format string.")
 
88
 
 
89
    def test_get_set_default_format_by_key(self):
 
90
        old_format = workingtree.format_registry.get_default()
 
91
        # default is 6
 
92
        format = SampleTreeFormat()
 
93
        workingtree.format_registry.register(format)
 
94
        self.addCleanup(workingtree.format_registry.remove, format)
 
95
        self.assertTrue(isinstance(old_format, workingtree_4.WorkingTreeFormat6))
 
96
        workingtree.format_registry.set_default_key(format.get_format_string())
 
97
        try:
 
98
            # the default branch format is used by the meta dir format
 
99
            # which is not the default bzrdir format at this point
 
100
            dir = bzrdir.BzrDirMetaFormat1().initialize('.')
 
101
            dir.create_repository()
 
102
            dir.create_branch()
 
103
            result = dir.create_workingtree()
 
104
            self.assertEqual(result, 'A tree')
 
105
        finally:
 
106
            workingtree.format_registry.set_default_key(
 
107
                old_format.get_format_string())
 
108
        self.assertEqual(old_format, workingtree.format_registry.get_default())
 
109
 
 
110
    def test_open(self):
 
111
        tree = self.make_branch_and_tree('.')
 
112
        open_direct = workingtree.WorkingTree.open('.')
 
113
        self.assertEqual(tree.basedir, open_direct.basedir)
 
114
        open_no_args = workingtree.WorkingTree.open()
 
115
        self.assertEqual(tree.basedir, open_no_args.basedir)
 
116
 
 
117
    def test_open_containing(self):
 
118
        tree = self.make_branch_and_tree('.')
 
119
        open_direct, relpath = workingtree.WorkingTree.open_containing('.')
 
120
        self.assertEqual(tree.basedir, open_direct.basedir)
 
121
        self.assertEqual('', relpath)
 
122
        open_no_args, relpath = workingtree.WorkingTree.open_containing()
 
123
        self.assertEqual(tree.basedir, open_no_args.basedir)
 
124
        self.assertEqual('', relpath)
 
125
        open_subdir, relpath = workingtree.WorkingTree.open_containing('subdir')
 
126
        self.assertEqual(tree.basedir, open_subdir.basedir)
 
127
        self.assertEqual('subdir', relpath)
 
128
 
 
129
 
 
130
class SampleTreeFormat(workingtree.WorkingTreeFormatMetaDir):
 
131
    """A sample format
 
132
 
 
133
    this format is initializable, unsupported to aid in testing the
 
134
    open and open_downlevel routines.
 
135
    """
 
136
 
 
137
    @classmethod
 
138
    def get_format_string(cls):
 
139
        """See WorkingTreeFormat.get_format_string()."""
 
140
        return "Sample tree format."
 
141
 
 
142
    def initialize(self, a_bzrdir, revision_id=None, from_branch=None,
 
143
                   accelerator_tree=None, hardlink=False):
 
144
        """Sample branches cannot be created."""
 
145
        t = a_bzrdir.get_workingtree_transport(self)
 
146
        t.put_bytes('format', self.get_format_string())
 
147
        return 'A tree'
 
148
 
 
149
    def is_supported(self):
 
150
        return False
 
151
 
 
152
    def open(self, transport, _found=False):
 
153
        return "opened tree."
 
154
 
 
155
 
 
156
class SampleExtraTreeFormat(workingtree.WorkingTreeFormat):
 
157
    """A sample format that does not support use in a metadir.
 
158
 
 
159
    """
 
160
 
 
161
    def get_format_string(self):
 
162
        # Not usable in a metadir, so no format string
 
163
        return None
 
164
 
 
165
    def initialize(self, a_bzrdir, revision_id=None, from_branch=None,
 
166
                   accelerator_tree=None, hardlink=False):
 
167
        raise NotImplementedError(self.initialize)
 
168
 
 
169
    def is_supported(self):
 
170
        return False
 
171
 
 
172
    def open(self, transport, _found=False):
 
173
        raise NotImplementedError(self.open)
 
174
 
 
175
 
 
176
class TestWorkingTreeFormat(TestCaseWithTransport):
 
177
    """Tests for the WorkingTreeFormat facility."""
 
178
 
 
179
    def test_find_format_string(self):
 
180
        # is the right format object found for a working tree?
 
181
        branch = self.make_branch('branch')
 
182
        self.assertRaises(errors.NoWorkingTree,
 
183
            workingtree.WorkingTreeFormatMetaDir.find_format_string, branch.bzrdir)
 
184
        transport = branch.bzrdir.get_workingtree_transport(None)
 
185
        transport.mkdir('.')
 
186
        transport.put_bytes("format", "some format name")
 
187
        # The format does not have to be known by Bazaar,
 
188
        # find_format_string just retrieves the name
 
189
        self.assertEquals("some format name",
 
190
            workingtree.WorkingTreeFormatMetaDir.find_format_string(branch.bzrdir))
 
191
 
 
192
    def test_find_format(self):
 
193
        # is the right format object found for a working tree?
 
194
        # create a branch with a few known format objects.
 
195
        self.build_tree(["foo/", "bar/"])
 
196
        def check_format(format, url):
 
197
            dir = format._matchingbzrdir.initialize(url)
 
198
            dir.create_repository()
 
199
            dir.create_branch()
 
200
            format.initialize(dir)
 
201
            t = transport.get_transport(url)
 
202
            found_format = workingtree.WorkingTreeFormatMetaDir.find_format(dir)
 
203
            self.assertIsInstance(found_format, format.__class__)
 
204
        check_format(workingtree_3.WorkingTreeFormat3(), "bar")
 
205
 
 
206
    def test_find_format_no_tree(self):
 
207
        dir = bzrdir.BzrDirMetaFormat1().initialize('.')
 
208
        self.assertRaises(errors.NoWorkingTree,
 
209
                          workingtree.WorkingTreeFormatMetaDir.find_format,
 
210
                          dir)
 
211
 
 
212
    def test_find_format_unknown_format(self):
 
213
        dir = bzrdir.BzrDirMetaFormat1().initialize('.')
 
214
        dir.create_repository()
 
215
        dir.create_branch()
 
216
        SampleTreeFormat().initialize(dir)
 
217
        self.assertRaises(errors.UnknownFormatError,
 
218
                          workingtree.WorkingTreeFormatMetaDir.find_format,
 
219
                          dir)
 
220
 
 
221
    def test_register_unregister_format(self):
 
222
        format = SampleTreeFormat()
 
223
        # make a control dir
 
224
        dir = bzrdir.BzrDirMetaFormat1().initialize('.')
 
225
        dir.create_repository()
 
226
        dir.create_branch()
 
227
        # make a branch
 
228
        format.initialize(dir)
 
229
        # register a format for it.
 
230
        self.applyDeprecated(symbol_versioning.deprecated_in((2, 4, 0)),
 
231
            workingtree.WorkingTreeFormat.register_format, format)
 
232
        self.assertTrue(format in 
 
233
            self.applyDeprecated(symbol_versioning.deprecated_in((2, 4, 0)),
 
234
                workingtree.WorkingTreeFormat.get_formats))
 
235
        # which branch.Open will refuse (not supported)
 
236
        self.assertRaises(errors.UnsupportedFormatError, workingtree.WorkingTree.open, '.')
 
237
        # but open_downlevel will work
 
238
        self.assertEqual(format.open(dir), workingtree.WorkingTree.open_downlevel('.'))
 
239
        # unregister the format
 
240
        self.applyDeprecated(symbol_versioning.deprecated_in((2, 4, 0)),
 
241
            workingtree.WorkingTreeFormat.unregister_format, format)
 
242
        self.assertFalse(format in
 
243
            self.applyDeprecated(symbol_versioning.deprecated_in((2, 4, 0)),
 
244
                workingtree.WorkingTreeFormat.get_formats))
 
245
 
 
246
 
 
247
class TestWorkingTreeIterEntriesByDir_wSubtrees(TestCaseWithTransport):
 
248
 
 
249
    def make_simple_tree(self):
 
250
        tree = self.make_branch_and_tree('tree', format='development-subtree')
 
251
        self.build_tree(['tree/a/', 'tree/a/b/', 'tree/a/b/c'])
 
252
        tree.set_root_id('root-id')
 
253
        tree.add(['a', 'a/b', 'a/b/c'], ['a-id', 'b-id', 'c-id'])
 
254
        tree.commit('initial')
 
255
        return tree
 
256
 
 
257
    def test_just_directory(self):
 
258
        tree = self.make_simple_tree()
 
259
        self.assertEqual([('directory', 'root-id'),
 
260
                          ('directory', 'a-id'),
 
261
                          ('directory', 'b-id'),
 
262
                          ('file', 'c-id')],
 
263
                         [(ie.kind, ie.file_id)
 
264
                          for path, ie in tree.iter_entries_by_dir()])
 
265
        subtree = self.make_branch_and_tree('tree/a/b')
 
266
        self.assertEqual([('tree-reference', 'b-id')],
 
267
                         [(ie.kind, ie.file_id)
 
268
                          for path, ie in tree.iter_entries_by_dir(['b-id'])])
 
269
 
 
270
    def test_direct_subtree(self):
 
271
        tree = self.make_simple_tree()
 
272
        subtree = self.make_branch_and_tree('tree/a/b')
 
273
        self.assertEqual([('directory', 'root-id'),
 
274
                          ('directory', 'a-id'),
 
275
                          ('tree-reference', 'b-id')],
 
276
                         [(ie.kind, ie.file_id)
 
277
                          for path, ie in tree.iter_entries_by_dir()])
 
278
 
 
279
    def test_indirect_subtree(self):
 
280
        tree = self.make_simple_tree()
 
281
        subtree = self.make_branch_and_tree('tree/a')
 
282
        self.assertEqual([('directory', 'root-id'),
 
283
                          ('tree-reference', 'a-id')],
 
284
                         [(ie.kind, ie.file_id)
 
285
                          for path, ie in tree.iter_entries_by_dir()])
 
286
 
 
287
 
 
288
class TestWorkingTreeFormatRegistry(TestCase):
 
289
 
 
290
    def setUp(self):
 
291
        super(TestWorkingTreeFormatRegistry, self).setUp()
 
292
        self.registry = workingtree.WorkingTreeFormatRegistry()
 
293
 
 
294
    def test_register_unregister_format(self):
 
295
        format = SampleTreeFormat()
 
296
        self.registry.register(format)
 
297
        self.assertEquals(format, self.registry.get("Sample tree format."))
 
298
        self.registry.remove(format)
 
299
        self.assertRaises(KeyError, self.registry.get, "Sample tree format.")
 
300
 
 
301
    def test_get_all(self):
 
302
        format = SampleTreeFormat()
 
303
        self.assertEquals([], self.registry._get_all())
 
304
        self.registry.register(format)
 
305
        self.assertEquals([format], self.registry._get_all())
 
306
 
 
307
    def test_register_extra(self):
 
308
        format = SampleExtraTreeFormat()
 
309
        self.assertEquals([], self.registry._get_all())
 
310
        self.registry.register_extra(format)
 
311
        self.assertEquals([format], self.registry._get_all())
 
312
 
 
313
    def test_register_extra_lazy(self):
 
314
        self.assertEquals([], self.registry._get_all())
 
315
        self.registry.register_extra_lazy("bzrlib.tests.test_workingtree",
 
316
            "SampleExtraTreeFormat")
 
317
        formats = self.registry._get_all()
 
318
        self.assertEquals(1, len(formats))
 
319
        self.assertIsInstance(formats[0], SampleExtraTreeFormat)
 
320
 
 
321
 
 
322
class TestWorkingTreeFormat3(TestCaseWithTransport):
 
323
    """Tests specific to WorkingTreeFormat3."""
 
324
 
 
325
    def test_disk_layout(self):
 
326
        control = bzrdir.BzrDirMetaFormat1().initialize(self.get_url())
 
327
        control.create_repository()
 
328
        control.create_branch()
 
329
        tree = workingtree_3.WorkingTreeFormat3().initialize(control)
 
330
        # we want:
 
331
        # format 'Bazaar-NG Working Tree format 3'
 
332
        # inventory = blank inventory
 
333
        # pending-merges = ''
 
334
        # stat-cache = ??
 
335
        # no inventory.basis yet
 
336
        t = control.get_workingtree_transport(None)
 
337
        self.assertEqualDiff('Bazaar-NG Working Tree format 3',
 
338
                             t.get('format').read())
 
339
        self.assertEqualDiff(t.get('inventory').read(),
 
340
                              '<inventory format="5">\n'
 
341
                              '</inventory>\n',
 
342
                             )
 
343
        self.assertEqualDiff('### bzr hashcache v5\n',
 
344
                             t.get('stat-cache').read())
 
345
        self.assertFalse(t.has('inventory.basis'))
 
346
        # no last-revision file means 'None' or 'NULLREVISION'
 
347
        self.assertFalse(t.has('last-revision'))
 
348
        # TODO RBC 20060210 do a commit, check the inventory.basis is created
 
349
        # correctly and last-revision file becomes present.
 
350
 
 
351
    def test_uses_lockdir(self):
 
352
        """WorkingTreeFormat3 uses its own LockDir:
 
353
 
 
354
            - lock is a directory
 
355
            - when the WorkingTree is locked, LockDir can see that
 
356
        """
 
357
        t = self.get_transport()
 
358
        url = self.get_url()
 
359
        dir = bzrdir.BzrDirMetaFormat1().initialize(url)
 
360
        repo = dir.create_repository()
 
361
        branch = dir.create_branch()
 
362
        try:
 
363
            tree = workingtree_3.WorkingTreeFormat3().initialize(dir)
 
364
        except errors.NotLocalUrl:
 
365
            raise TestSkipped('Not a local URL')
 
366
        self.assertIsDirectory('.bzr', t)
 
367
        self.assertIsDirectory('.bzr/checkout', t)
 
368
        self.assertIsDirectory('.bzr/checkout/lock', t)
 
369
        our_lock = LockDir(t, '.bzr/checkout/lock')
 
370
        self.assertEquals(our_lock.peek(), None)
 
371
        tree.lock_write()
 
372
        self.assertTrue(our_lock.peek())
 
373
        tree.unlock()
 
374
        self.assertEquals(our_lock.peek(), None)
 
375
 
 
376
    def test_missing_pending_merges(self):
 
377
        control = bzrdir.BzrDirMetaFormat1().initialize(self.get_url())
 
378
        control.create_repository()
 
379
        control.create_branch()
 
380
        tree = workingtree_3.WorkingTreeFormat3().initialize(control)
 
381
        tree._transport.delete("pending-merges")
 
382
        self.assertEqual([], tree.get_parent_ids())
 
383
 
 
384
 
 
385
class InstrumentedTree(object):
 
386
    """A instrumented tree to check the needs_tree_write_lock decorator."""
 
387
 
 
388
    def __init__(self):
 
389
        self._locks = []
 
390
 
 
391
    def lock_tree_write(self):
 
392
        self._locks.append('t')
 
393
 
 
394
    @needs_tree_write_lock
 
395
    def method_with_tree_write_lock(self, *args, **kwargs):
 
396
        """A lock_tree_write decorated method that returns its arguments."""
 
397
        return args, kwargs
 
398
 
 
399
    @needs_tree_write_lock
 
400
    def method_that_raises(self):
 
401
        """This method causes an exception when called with parameters.
 
402
 
 
403
        This allows the decorator code to be checked - it should still call
 
404
        unlock.
 
405
        """
 
406
 
 
407
    def unlock(self):
 
408
        self._locks.append('u')
 
409
 
 
410
 
 
411
class TestInstrumentedTree(TestCase):
 
412
 
 
413
    def test_needs_tree_write_lock(self):
 
414
        """@needs_tree_write_lock should be semantically transparent."""
 
415
        tree = InstrumentedTree()
 
416
        self.assertEqual(
 
417
            'method_with_tree_write_lock',
 
418
            tree.method_with_tree_write_lock.__name__)
 
419
        self.assertDocstring(
 
420
            "A lock_tree_write decorated method that returns its arguments.",
 
421
            tree.method_with_tree_write_lock)
 
422
        args = (1, 2, 3)
 
423
        kwargs = {'a':'b'}
 
424
        result = tree.method_with_tree_write_lock(1,2,3, a='b')
 
425
        self.assertEqual((args, kwargs), result)
 
426
        self.assertEqual(['t', 'u'], tree._locks)
 
427
        self.assertRaises(TypeError, tree.method_that_raises, 'foo')
 
428
        self.assertEqual(['t', 'u', 't', 'u'], tree._locks)
 
429
 
 
430
 
 
431
class TestRevert(TestCaseWithTransport):
 
432
 
 
433
    def test_revert_conflicts_recursive(self):
 
434
        this_tree = self.make_branch_and_tree('this-tree')
 
435
        self.build_tree_contents([('this-tree/foo/',),
 
436
                                  ('this-tree/foo/bar', 'bar')])
 
437
        this_tree.add(['foo', 'foo/bar'])
 
438
        this_tree.commit('created foo/bar')
 
439
        other_tree = this_tree.bzrdir.sprout('other-tree').open_workingtree()
 
440
        self.build_tree_contents([('other-tree/foo/bar', 'baz')])
 
441
        other_tree.commit('changed bar')
 
442
        self.build_tree_contents([('this-tree/foo/bar', 'qux')])
 
443
        this_tree.commit('changed qux')
 
444
        this_tree.merge_from_branch(other_tree.branch)
 
445
        self.assertEqual(1, len(this_tree.conflicts()))
 
446
        this_tree.revert(['foo'])
 
447
        self.assertEqual(0, len(this_tree.conflicts()))
 
448
 
 
449
 
 
450
class TestAutoResolve(TestCaseWithTransport):
 
451
 
 
452
    def test_auto_resolve(self):
 
453
        base = self.make_branch_and_tree('base')
 
454
        self.build_tree_contents([('base/hello', 'Hello')])
 
455
        base.add('hello', 'hello_id')
 
456
        base.commit('Hello')
 
457
        other = base.bzrdir.sprout('other').open_workingtree()
 
458
        self.build_tree_contents([('other/hello', 'hELLO')])
 
459
        other.commit('Case switch')
 
460
        this = base.bzrdir.sprout('this').open_workingtree()
 
461
        self.assertPathExists('this/hello')
 
462
        self.build_tree_contents([('this/hello', 'Hello World')])
 
463
        this.commit('Add World')
 
464
        this.merge_from_branch(other.branch)
 
465
        self.assertEqual([conflicts.TextConflict('hello', 'hello_id')],
 
466
                         this.conflicts())
 
467
        this.auto_resolve()
 
468
        self.assertEqual([conflicts.TextConflict('hello', 'hello_id')],
 
469
                         this.conflicts())
 
470
        self.build_tree_contents([('this/hello', '<<<<<<<')])
 
471
        this.auto_resolve()
 
472
        self.assertEqual([conflicts.TextConflict('hello', 'hello_id')],
 
473
                         this.conflicts())
 
474
        self.build_tree_contents([('this/hello', '=======')])
 
475
        this.auto_resolve()
 
476
        self.assertEqual([conflicts.TextConflict('hello', 'hello_id')],
 
477
                         this.conflicts())
 
478
        self.build_tree_contents([('this/hello', '\n>>>>>>>')])
 
479
        remaining, resolved = this.auto_resolve()
 
480
        self.assertEqual([conflicts.TextConflict('hello', 'hello_id')],
 
481
                         this.conflicts())
 
482
        self.assertEqual([], resolved)
 
483
        self.build_tree_contents([('this/hello', 'hELLO wORLD')])
 
484
        remaining, resolved = this.auto_resolve()
 
485
        self.assertEqual([], this.conflicts())
 
486
        self.assertEqual([conflicts.TextConflict('hello', 'hello_id')],
 
487
                         resolved)
 
488
        self.assertPathDoesNotExist('this/hello.BASE')
 
489
 
 
490
    def test_auto_resolve_dir(self):
 
491
        tree = self.make_branch_and_tree('tree')
 
492
        self.build_tree(['tree/hello/'])
 
493
        tree.add('hello', 'hello-id')
 
494
        file_conflict = conflicts.TextConflict('file', 'hello-id')
 
495
        tree.set_conflicts(conflicts.ConflictList([file_conflict]))
 
496
        tree.auto_resolve()
 
497
 
 
498
 
 
499
class TestFindTrees(TestCaseWithTransport):
 
500
 
 
501
    def test_find_trees(self):
 
502
        self.make_branch_and_tree('foo')
 
503
        self.make_branch_and_tree('foo/bar')
 
504
        # Sticking a tree inside a control dir is heinous, so let's skip it
 
505
        self.make_branch_and_tree('foo/.bzr/baz')
 
506
        self.make_branch('qux')
 
507
        trees = workingtree.WorkingTree.find_trees('.')
 
508
        self.assertEqual(2, len(list(trees)))