test/test_traversal.py

   1 import http.cookies
   2 import re
   3 import xml.etree.ElementTree
   4
   5 import pytest
   6
   7 from yt_dlp.utils import dict_get, int_or_none, str_or_none
   8 from yt_dlp.utils.traversal import traverse_obj
   9
  10 _TEST_DATA = {
  11     100: 100,
  12     1.2: 1.2,
  13     'str': 'str',
  14     'None': None,
  15     '...': ...,
  16     'urls': [
  17         {'index': 0, 'url': 'https://www.example.com/0'},
  18         {'index': 1, 'url': 'https://www.example.com/1'},
  19     ],
  20     'data': (
  21         {'index': 2},
  22         {'index': 3},
  23     ),
  24     'dict': {},
  25 }
  26
  27
  28 class TestTraversal:
  29     def test_traversal_base(self):
  30         assert traverse_obj(_TEST_DATA, ('str',)) == 'str', \
  31             'allow tuple path'
  32         assert traverse_obj(_TEST_DATA, ['str']) == 'str', \
  33             'allow list path'
  34         assert traverse_obj(_TEST_DATA, (value for value in ('str',))) == 'str', \
  35             'allow iterable path'
  36         assert traverse_obj(_TEST_DATA, 'str') == 'str', \
  37             'single items should be treated as a path'
  38         assert traverse_obj(_TEST_DATA, 100) == 100, \
  39             'allow int path'
  40         assert traverse_obj(_TEST_DATA, 1.2) == 1.2, \
  41             'allow float path'
  42         assert traverse_obj(_TEST_DATA, None) == _TEST_DATA, \
  43             '`None` should not perform any modification'
  44
  45     def test_traversal_ellipsis(self):
  46         assert traverse_obj(_TEST_DATA, ...) == [x for x in _TEST_DATA.values() if x not in (None, {})], \
  47             '`...` should give all non discarded values'
  48         assert traverse_obj(_TEST_DATA, ('urls', 0, ...)) == list(_TEST_DATA['urls'][0].values()), \
  49             '`...` selection for dicts should select all values'
  50         assert traverse_obj(_TEST_DATA, (..., ..., 'url')) == ['https://www.example.com/0', 'https://www.example.com/1'], \
  51             'nested `...` queries should work'
  52         assert traverse_obj(_TEST_DATA, (..., ..., 'index')) == list(range(4)), \
  53             '`...` query result should be flattened'
  54         assert traverse_obj(iter(range(4)), ...) == list(range(4)), \
  55             '`...` should accept iterables'
  56
  57     def test_traversal_function(self):
  58         filter_func = lambda x, y: x == 'urls' and isinstance(y, list)
  59         assert traverse_obj(_TEST_DATA, filter_func) == [_TEST_DATA['urls']], \
  60             'function as query key should perform a filter based on (key, value)'
  61         assert traverse_obj(_TEST_DATA, lambda _, x: isinstance(x[0], str)) == ['str'], \
  62             'exceptions in the query function should be catched'
  63         assert traverse_obj(iter(range(4)), lambda _, x: x % 2 == 0) == [0, 2], \
  64             'function key should accept iterables'
  65         # Wrong function signature should raise (debug mode)
  66         with pytest.raises(Exception):
  67             traverse_obj(_TEST_DATA, lambda a: ...)
  68         with pytest.raises(Exception):
  69             traverse_obj(_TEST_DATA, lambda a, b, c: ...)
  70
  71     def test_traversal_set(self):
  72         # transformation/type, like `expected_type`
  73         assert traverse_obj(_TEST_DATA, (..., {str.upper})) == ['STR'], \
  74             'Function in set should be a transformation'
  75         assert traverse_obj(_TEST_DATA, (..., {str})) == ['str'], \
  76             'Type in set should be a type filter'
  77         assert traverse_obj(_TEST_DATA, (..., {str, int})) == [100, 'str'], \
  78             'Multiple types in set should be a type filter'
  79         assert traverse_obj(_TEST_DATA, {dict}) == _TEST_DATA, \
  80             'A single set should be wrapped into a path'
  81         assert traverse_obj(_TEST_DATA, (..., {str.upper})) == ['STR'], \
  82             'Transformation function should not raise'
  83         expected = [x for x in map(str_or_none, _TEST_DATA.values()) if x is not None]
  84         assert traverse_obj(_TEST_DATA, (..., {str_or_none})) == expected, \
  85             'Function in set should be a transformation'
  86         assert traverse_obj(_TEST_DATA, ('fail', {lambda _: 'const'})) == 'const', \
  87             'Function in set should always be called'
  88         # Sets with length < 1 or > 1 not including only types should raise
  89         with pytest.raises(Exception):
  90             traverse_obj(_TEST_DATA, set())
  91         with pytest.raises(Exception):
  92             traverse_obj(_TEST_DATA, {str.upper, str})
  93
  94     def test_traversal_slice(self):
  95         _SLICE_DATA = [0, 1, 2, 3, 4]
  96
  97         assert traverse_obj(_TEST_DATA, ('dict', slice(1))) is None, \
  98             'slice on a dictionary should not throw'
  99         assert traverse_obj(_SLICE_DATA, slice(1)) == _SLICE_DATA[:1], \
 100             'slice key should apply slice to sequence'
 101         assert traverse_obj(_SLICE_DATA, slice(1, 2)) == _SLICE_DATA[1:2], \
 102             'slice key should apply slice to sequence'
 103         assert traverse_obj(_SLICE_DATA, slice(1, 4, 2)) == _SLICE_DATA[1:4:2], \
 104             'slice key should apply slice to sequence'
 105
 106     def test_traversal_alternatives(self):
 107         assert traverse_obj(_TEST_DATA, 'fail', 'str') == 'str', \
 108             'multiple `paths` should be treated as alternative paths'
 109         assert traverse_obj(_TEST_DATA, 'str', 100) == 'str', \
 110             'alternatives should exit early'
 111         assert traverse_obj(_TEST_DATA, 'fail', 'fail') is None, \
 112             'alternatives should return `default` if exhausted'
 113         assert traverse_obj(_TEST_DATA, (..., 'fail'), 100) == 100, \
 114             'alternatives should track their own branching return'
 115         assert traverse_obj(_TEST_DATA, ('dict', ...), ('data', ...)) == list(_TEST_DATA['data']), \
 116             'alternatives on empty objects should search further'
 117
 118     def test_traversal_branching_nesting(self):
 119         assert traverse_obj(_TEST_DATA, ('urls', (3, 0), 'url')) == ['https://www.example.com/0'], \
 120             'tuple as key should be treated as branches'
 121         assert traverse_obj(_TEST_DATA, ('urls', [3, 0], 'url')) == ['https://www.example.com/0'], \
 122             'list as key should be treated as branches'
 123         assert traverse_obj(_TEST_DATA, ('urls', ((1, 'fail'), (0, 'url')))) == ['https://www.example.com/0'], \
 124             'double nesting in path should be treated as paths'
 125         assert traverse_obj(['0', [1, 2]], [(0, 1), 0]) == [1], \
 126             'do not fail early on branching'
 127         expected = ['https://www.example.com/0', 'https://www.example.com/1']
 128         assert traverse_obj(_TEST_DATA, ('urls', ((0, ('fail', 'url')), (1, 'url')))) == expected, \
 129             'tripple nesting in path should be treated as branches'
 130         assert traverse_obj(_TEST_DATA, ('urls', ('fail', (..., 'url')))) == expected, \
 131             'ellipsis as branch path start gets flattened'
 132
 133     def test_traversal_dict(self):
 134         assert traverse_obj(_TEST_DATA, {0: 100, 1: 1.2}) == {0: 100, 1: 1.2}, \
 135             'dict key should result in a dict with the same keys'
 136         expected = {0: 'https://www.example.com/0'}
 137         assert traverse_obj(_TEST_DATA, {0: ('urls', 0, 'url')}) == expected, \
 138             'dict key should allow paths'
 139         expected = {0: ['https://www.example.com/0']}
 140         assert traverse_obj(_TEST_DATA, {0: ('urls', (3, 0), 'url')}) == expected, \
 141             'tuple in dict path should be treated as branches'
 142         assert traverse_obj(_TEST_DATA, {0: ('urls', ((1, 'fail'), (0, 'url')))}) == expected, \
 143             'double nesting in dict path should be treated as paths'
 144         expected = {0: ['https://www.example.com/1', 'https://www.example.com/0']}
 145         assert traverse_obj(_TEST_DATA, {0: ('urls', ((1, ('fail', 'url')), (0, 'url')))}) == expected, \
 146             'tripple nesting in dict path should be treated as branches'
 147         assert traverse_obj(_TEST_DATA, {0: 'fail'}) == {}, \
 148             'remove `None` values when top level dict key fails'
 149         assert traverse_obj(_TEST_DATA, {0: 'fail'}, default=...) == {0: ...}, \
 150             'use `default` if key fails and `default`'
 151         assert traverse_obj(_TEST_DATA, {0: 'dict'}) == {}, \
 152             'remove empty values when dict key'
 153         assert traverse_obj(_TEST_DATA, {0: 'dict'}, default=...) == {0: ...}, \
 154             'use `default` when dict key and `default`'
 155         assert traverse_obj(_TEST_DATA, {0: {0: 'fail'}}) == {}, \
 156             'remove empty values when nested dict key fails'
 157         assert traverse_obj(None, {0: 'fail'}) == {}, \
 158             'default to dict if pruned'
 159         assert traverse_obj(None, {0: 'fail'}, default=...) == {0: ...}, \
 160             'default to dict if pruned and default is given'
 161         assert traverse_obj(_TEST_DATA, {0: {0: 'fail'}}, default=...) == {0: {0: ...}}, \
 162             'use nested `default` when nested dict key fails and `default`'
 163         assert traverse_obj(_TEST_DATA, {0: ('dict', ...)}) == {}, \
 164             'remove key if branch in dict key not successful'
 165
 166     def test_traversal_default(self):
 167         _DEFAULT_DATA = {'None': None, 'int': 0, 'list': []}
 168
 169         assert traverse_obj(_DEFAULT_DATA, 'fail') is None, \
 170             'default value should be `None`'
 171         assert traverse_obj(_DEFAULT_DATA, 'fail', 'fail', default=...) == ..., \
 172             'chained fails should result in default'
 173         assert traverse_obj(_DEFAULT_DATA, 'None', 'int') == 0, \
 174             'should not short cirquit on `None`'
 175         assert traverse_obj(_DEFAULT_DATA, 'fail', default=1) == 1, \
 176             'invalid dict key should result in `default`'
 177         assert traverse_obj(_DEFAULT_DATA, 'None', default=1) == 1, \
 178             '`None` is a deliberate sentinel and should become `default`'
 179         assert traverse_obj(_DEFAULT_DATA, ('list', 10)) is None, \
 180             '`IndexError` should result in `default`'
 181         assert traverse_obj(_DEFAULT_DATA, (..., 'fail'), default=1) == 1, \
 182             'if branched but not successful return `default` if defined, not `[]`'
 183         assert traverse_obj(_DEFAULT_DATA, (..., 'fail'), default=None) is None, \
 184             'if branched but not successful return `default` even if `default` is `None`'
 185         assert traverse_obj(_DEFAULT_DATA, (..., 'fail')) == [], \
 186             'if branched but not successful return `[]`, not `default`'
 187         assert traverse_obj(_DEFAULT_DATA, ('list', ...)) == [], \
 188             'if branched but object is empty return `[]`, not `default`'
 189         assert traverse_obj(None, ...) == [], \
 190             'if branched but object is `None` return `[]`, not `default`'
 191         assert traverse_obj({0: None}, (0, ...)) == [], \
 192             'if branched but state is `None` return `[]`, not `default`'
 193
 194     @pytest.mark.parametrize('path', [
 195         ('fail', ...),
 196         (..., 'fail'),
 197         100 * ('fail',) + (...,),
 198         (...,) + 100 * ('fail',),
 199     ])
 200     def test_traversal_branching(self, path):
 201         assert traverse_obj({}, path) == [], \
 202             'if branched but state is `None`, return `[]` (not `default`)'
 203         assert traverse_obj({}, 'fail', path) == [], \
 204             'if branching in last alternative and previous did not match, return `[]` (not `default`)'
 205         assert traverse_obj({0: 'x'}, 0, path) == 'x', \
 206             'if branching in last alternative and previous did match, return single value'
 207         assert traverse_obj({0: 'x'}, path, 0) == 'x', \
 208             'if branching in first alternative and non-branching path does match, return single value'
 209         assert traverse_obj({}, path, 'fail') is None, \
 210             'if branching in first alternative and non-branching path does not match, return `default`'
 211
 212     def test_traversal_expected_type(self):
 213         _EXPECTED_TYPE_DATA = {'str': 'str', 'int': 0}
 214
 215         assert traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=str) == 'str', \
 216             'accept matching `expected_type` type'
 217         assert traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=int) is None, \
 218             'reject non matching `expected_type` type'
 219         assert traverse_obj(_EXPECTED_TYPE_DATA, 'int', expected_type=lambda x: str(x)) == '0', \
 220             'transform type using type function'
 221         assert traverse_obj(_EXPECTED_TYPE_DATA, 'str', expected_type=lambda _: 1 / 0) is None, \
 222             'wrap expected_type fuction in try_call'
 223         assert traverse_obj(_EXPECTED_TYPE_DATA, ..., expected_type=str) == ['str'], \
 224             'eliminate items that expected_type fails on'
 225         assert traverse_obj(_TEST_DATA, {0: 100, 1: 1.2}, expected_type=int) == {0: 100}, \
 226             'type as expected_type should filter dict values'
 227         assert traverse_obj(_TEST_DATA, {0: 100, 1: 1.2, 2: 'None'}, expected_type=str_or_none) == {0: '100', 1: '1.2'}, \
 228             'function as expected_type should transform dict values'
 229         assert traverse_obj(_TEST_DATA, ({0: 1.2}, 0, {int_or_none}), expected_type=int) == 1, \
 230             'expected_type should not filter non final dict values'
 231         assert traverse_obj(_TEST_DATA, {0: {0: 100, 1: 'str'}}, expected_type=int) == {0: {0: 100}}, \
 232             'expected_type should transform deep dict values'
 233         assert traverse_obj(_TEST_DATA, [({0: '...'}, {0: '...'})], expected_type=type(...)) == [{0: ...}, {0: ...}], \
 234             'expected_type should transform branched dict values'
 235         assert traverse_obj({1: {3: 4}}, [(1, 2), 3], expected_type=int) == [4], \
 236             'expected_type regression for type matching in tuple branching'
 237         assert traverse_obj(_TEST_DATA, ['data', ...], expected_type=int) == [], \
 238             'expected_type regression for type matching in dict result'
 239
 240     def test_traversal_get_all(self):
 241         _GET_ALL_DATA = {'key': [0, 1, 2]}
 242
 243         assert traverse_obj(_GET_ALL_DATA, ('key', ...), get_all=False) == 0, \
 244             'if not `get_all`, return only first matching value'
 245         assert traverse_obj(_GET_ALL_DATA, ..., get_all=False) == [0, 1, 2], \
 246             'do not overflatten if not `get_all`'
 247
 248     def test_traversal_casesense(self):
 249         _CASESENSE_DATA = {
 250             'KeY': 'value0',
 251             0: {
 252                 'KeY': 'value1',
 253                 0: {'KeY': 'value2'},
 254             },
 255         }
 256
 257         assert traverse_obj(_CASESENSE_DATA, 'key') is None, \
 258             'dict keys should be case sensitive unless `casesense`'
 259         assert traverse_obj(_CASESENSE_DATA, 'keY', casesense=False) == 'value0', \
 260             'allow non matching key case if `casesense`'
 261         assert traverse_obj(_CASESENSE_DATA, [0, ('keY',)], casesense=False) == ['value1'], \
 262             'allow non matching key case in branch if `casesense`'
 263         assert traverse_obj(_CASESENSE_DATA, [0, ([0, 'keY'],)], casesense=False) == ['value2'], \
 264             'allow non matching key case in branch path if `casesense`'
 265
 266     def test_traversal_traverse_string(self):
 267         _TRAVERSE_STRING_DATA = {'str': 'str', 1.2: 1.2}
 268
 269         assert traverse_obj(_TRAVERSE_STRING_DATA, ('str', 0)) is None, \
 270             'do not traverse into string if not `traverse_string`'
 271         assert traverse_obj(_TRAVERSE_STRING_DATA, ('str', 0), traverse_string=True) == 's', \
 272             'traverse into string if `traverse_string`'
 273         assert traverse_obj(_TRAVERSE_STRING_DATA, (1.2, 1), traverse_string=True) == '.', \
 274             'traverse into converted data if `traverse_string`'
 275         assert traverse_obj(_TRAVERSE_STRING_DATA, ('str', ...), traverse_string=True) == 'str', \
 276             '`...` should result in string (same value) if `traverse_string`'
 277         assert traverse_obj(_TRAVERSE_STRING_DATA, ('str', slice(0, None, 2)), traverse_string=True) == 'sr', \
 278             '`slice` should result in string if `traverse_string`'
 279         assert traverse_obj(_TRAVERSE_STRING_DATA, ('str', lambda i, v: i or v == 's'), traverse_string=True) == 'str', \
 280             'function should result in string if `traverse_string`'
 281         assert traverse_obj(_TRAVERSE_STRING_DATA, ('str', (0, 2)), traverse_string=True) == ['s', 'r'], \
 282             'branching should result in list if `traverse_string`'
 283         assert traverse_obj({}, (0, ...), traverse_string=True) == [], \
 284             'branching should result in list if `traverse_string`'
 285         assert traverse_obj({}, (0, lambda x, y: True), traverse_string=True) == [], \
 286             'branching should result in list if `traverse_string`'
 287         assert traverse_obj({}, (0, slice(1)), traverse_string=True) == [], \
 288             'branching should result in list if `traverse_string`'
 289
 290     def test_traversal_re(self):
 291         mobj = re.fullmatch(r'0(12)(?P<group>3)(4)?', '0123')
 292         assert traverse_obj(mobj, ...) == [x for x in mobj.groups() if x is not None], \
 293             '`...` on a `re.Match` should give its `groups()`'
 294         assert traverse_obj(mobj, lambda k, _: k in (0, 2)) == ['0123', '3'], \
 295             'function on a `re.Match` should give groupno, value starting at 0'
 296         assert traverse_obj(mobj, 'group') == '3', \
 297             'str key on a `re.Match` should give group with that name'
 298         assert traverse_obj(mobj, 2) == '3', \
 299             'int key on a `re.Match` should give group with that name'
 300         assert traverse_obj(mobj, 'gRoUp', casesense=False) == '3', \
 301             'str key on a `re.Match` should respect casesense'
 302         assert traverse_obj(mobj, 'fail') is None, \
 303             'failing str key on a `re.Match` should return `default`'
 304         assert traverse_obj(mobj, 'gRoUpS', casesense=False) is None, \
 305             'failing str key on a `re.Match` should return `default`'
 306         assert traverse_obj(mobj, 8) is None, \
 307             'failing int key on a `re.Match` should return `default`'
 308         assert traverse_obj(mobj, lambda k, _: k in (0, 'group')) == ['0123', '3'], \
 309             'function on a `re.Match` should give group name as well'
 310
 311     def test_traversal_xml_etree(self):
 312         etree = xml.etree.ElementTree.fromstring('''<?xml version="1.0"?>
 313         <data>
 314             <country name="Liechtenstein">
 315                 <rank>1</rank>
 316                 <year>2008</year>
 317                 <gdppc>141100</gdppc>
 318                 <neighbor name="Austria" direction="E"/>
 319                 <neighbor name="Switzerland" direction="W"/>
 320             </country>
 321             <country name="Singapore">
 322                 <rank>4</rank>
 323                 <year>2011</year>
 324                 <gdppc>59900</gdppc>
 325                 <neighbor name="Malaysia" direction="N"/>
 326             </country>
 327             <country name="Panama">
 328                 <rank>68</rank>
 329                 <year>2011</year>
 330                 <gdppc>13600</gdppc>
 331                 <neighbor name="Costa Rica" direction="W"/>
 332                 <neighbor name="Colombia" direction="E"/>
 333             </country>
 334         </data>''')
 335         assert traverse_obj(etree, '') == etree, \
 336             'empty str key should return the element itself'
 337         assert traverse_obj(etree, 'country') == list(etree), \
 338             'str key should lead all children with that tag name'
 339         assert traverse_obj(etree, ...) == list(etree), \
 340             '`...` as key should return all children'
 341         assert traverse_obj(etree, lambda _, x: x[0].text == '4') == [etree[1]], \
 342             'function as key should get element as value'
 343         assert traverse_obj(etree, lambda i, _: i == 1) == [etree[1]], \
 344             'function as key should get index as key'
 345         assert traverse_obj(etree, 0) == etree[0], \
 346             'int key should return the nth child'
 347         expected = ['Austria', 'Switzerland', 'Malaysia', 'Costa Rica', 'Colombia']
 348         assert traverse_obj(etree, './/neighbor/@name') == expected, \
 349             '`@<attribute>` at end of path should give that attribute'
 350         assert traverse_obj(etree, '//neighbor/@fail') == [None, None, None, None, None], \
 351             '`@<nonexistant>` at end of path should give `None`'
 352         assert traverse_obj(etree, ('//neighbor/@', 2)) == {'name': 'Malaysia', 'direction': 'N'}, \
 353             '`@` should give the full attribute dict'
 354         assert traverse_obj(etree, '//year/text()') == ['2008', '2011', '2011'], \
 355             '`text()` at end of path should give the inner text'
 356         assert traverse_obj(etree, '//*[@direction]/@direction') == ['E', 'W', 'N', 'W', 'E'], \
 357             'full Python xpath features should be supported'
 358         assert traverse_obj(etree, (0, '@name')) == 'Liechtenstein', \
 359             'special transformations should act on current element'
 360         assert traverse_obj(etree, ('country', 0, ..., 'text()', {int_or_none})) == [1, 2008, 141100], \
 361             'special transformations should act on current element'
 362
 363     def test_traversal_unbranching(self):
 364         assert traverse_obj(_TEST_DATA, [(100, 1.2), all]) == [100, 1.2], \
 365             '`all` should give all results as list'
 366         assert traverse_obj(_TEST_DATA, [(100, 1.2), any]) == 100, \
 367             '`any` should give the first result'
 368         assert traverse_obj(_TEST_DATA, [100, all]) == [100], \
 369             '`all` should give list if non branching'
 370         assert traverse_obj(_TEST_DATA, [100, any]) == 100, \
 371             '`any` should give single item if non branching'
 372         assert traverse_obj(_TEST_DATA, [('dict', 'None', 100), all]) == [100], \
 373             '`all` should filter `None` and empty dict'
 374         assert traverse_obj(_TEST_DATA, [('dict', 'None', 100), any]) == 100, \
 375             '`any` should filter `None` and empty dict'
 376         assert traverse_obj(_TEST_DATA, [{
 377             'all': [('dict', 'None', 100, 1.2), all],
 378             'any': [('dict', 'None', 100, 1.2), any],
 379         }]) == {'all': [100, 1.2], 'any': 100}, \
 380             '`all`/`any` should apply to each dict path separately'
 381         assert traverse_obj(_TEST_DATA, [{
 382             'all': [('dict', 'None', 100, 1.2), all],
 383             'any': [('dict', 'None', 100, 1.2), any],
 384         }], get_all=False) == {'all': [100, 1.2], 'any': 100}, \
 385             '`all`/`any` should apply to dict regardless of `get_all`'
 386         assert traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), all, {float}]) is None, \
 387             '`all` should reset branching status'
 388         assert traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), any, {float}]) is None, \
 389             '`any` should reset branching status'
 390         assert traverse_obj(_TEST_DATA, [('dict', 'None', 100, 1.2), all, ..., {float}]) == [1.2], \
 391             '`all` should allow further branching'
 392         assert traverse_obj(_TEST_DATA, [('dict', 'None', 'urls', 'data'), any, ..., 'index']) == [0, 1], \
 393             '`any` should allow further branching'
 394
 395     def test_traversal_morsel(self):
 396         values = {
 397             'expires': 'a',
 398             'path': 'b',
 399             'comment': 'c',
 400             'domain': 'd',
 401             'max-age': 'e',
 402             'secure': 'f',
 403             'httponly': 'g',
 404             'version': 'h',
 405             'samesite': 'i',
 406         }
 407         morsel = http.cookies.Morsel()
 408         morsel.set('item_key', 'item_value', 'coded_value')
 409         morsel.update(values)
 410         values['key'] = 'item_key'
 411         values['value'] = 'item_value'
 412
 413         for key, value in values.items():
 414             assert traverse_obj(morsel, key) == value, \
 415                 'Morsel should provide access to all values'
 416         assert traverse_obj(morsel, ...) == list(values.values()), \
 417             '`...` should yield all values'
 418         assert traverse_obj(morsel, lambda k, v: True) == list(values.values()), \
 419             'function key should yield all values'
 420         assert traverse_obj(morsel, [(None,), any]) == morsel, \
 421             'Morsel should not be implicitly changed to dict on usage'
 422
 423
 424 class TestDictGet:
 425     def test_dict_get(self):
 426         FALSE_VALUES = {
 427             'none': None,
 428             'false': False,
 429             'zero': 0,
 430             'empty_string': '',
 431             'empty_list': [],
 432         }
 433         d = {**FALSE_VALUES, 'a': 42}
 434         assert dict_get(d, 'a') == 42
 435         assert dict_get(d, 'b') is None
 436         assert dict_get(d, 'b', 42) == 42
 437         assert dict_get(d, ('a',)) == 42
 438         assert dict_get(d, ('b', 'a')) == 42
 439         assert dict_get(d, ('b', 'c', 'a', 'd')) == 42
 440         assert dict_get(d, ('b', 'c')) is None
 441         assert dict_get(d, ('b', 'c'), 42) == 42
 442         for key, false_value in FALSE_VALUES.items():
 443             assert dict_get(d, ('b', 'c', key)) is None
 444             assert dict_get(d, ('b', 'c', key), skip_false_values=False) == false_value