[JSInterp] Add tests and relevant functionality from yt-dlp

* thx seproDev, bashonly: yt-dlp/yt-dlp#12760, yt-dlp/yt-dlp#12761: - Improve nested attribute support - Pass global stack when extracting objects - interpret_statement: Match attribute before indexing - Fix assignment to array elements with nested brackets - Add new signature tests - Invalidate JS function cache - Avoid testdata dupes now that we cache by URL * rework nsig function name search * fully fixes #33102 * update cache required versions * update program version
2025-04-04 12:53:28 +01:00 · 2025-04-04 12:53:28 +01:00 · c052a16f72
commit c052a16f72
--- a/test/test_jsinterp.py
+++ b/test/test_jsinterp.py
@ -180,6 +180,7 @@ class TestJSInterpreter(unittest.TestCase):
        self._test('function f(){var x = 20; x = 30 + 1; return x;}', 31)
        self._test('function f(){var x = 20; x += 30 + 1; return x;}', 51)
        self._test('function f(){var x = 20; x -= 30 + 1; return x;}', -11)
+        self._test('function f(){var x = 2; var y = ["a", "b"]; y[x%y["length"]]="z"; return y}', ['z', 'b'])

    def test_comments(self):
        self._test('''
@ -552,6 +553,8 @@ class TestJSInterpreter(unittest.TestCase):
        test_result = list('test')
        tests = [
            'function f(a, b){return a.split(b)}',
+            'function f(a, b){return a["split"](b)}',
+            'function f(a, b){let x = ["split"]; return a[x[0]](b)}',
            'function f(a, b){return String.prototype.split.call(a, b)}',
            'function f(a, b){return String.prototype.split.apply(a, [b])}',
        ]
@ -602,6 +605,9 @@ class TestJSInterpreter(unittest.TestCase):
        self._test('function f(){return "012345678".slice(-1, 1)}', '')
        self._test('function f(){return "012345678".slice(-3, -1)}', '67')

+    def test_splice(self):
+        self._test('function f(){var T = ["0", "1", "2"]; T["splice"](2, 1, "0")[0]; return T }', ['0', '1', '0'])
+
    def test_pop(self):
        # pop
        self._test('function f(){var a = [0, 1, 2, 3, 4, 5, 6, 7, 8]; return [a.pop(), a]}',
@ -636,6 +642,16 @@ class TestJSInterpreter(unittest.TestCase):
                   'return [ret.length, ret[0][0], ret[1][1], ret[0][2]]}',
                   [2, 4, 1, [4, 2]])

+    def test_extract_function(self):
+        jsi = JSInterpreter('function a(b) { return b + 1; }')
+        func = jsi.extract_function('a')
+        self.assertEqual(func([2]), 3)
+
+    def test_extract_function_with_global_stack(self):
+        jsi = JSInterpreter('function c(d) { return d + e + f + g; }')
+        func = jsi.extract_function('c', {'e': 10}, {'f': 100, 'g': 1000})
+        self.assertEqual(func([1]), 1111)
+

 if __name__ == '__main__':
    unittest.main()
--- a/test/test_youtube_signature.py
+++ b/test/test_youtube_signature.py
@ -94,11 +94,51 @@ _SIG_TESTS = [
        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
        '0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpz2ICs6EVdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
    ),
+    (
+        'https://www.youtube.com/s/player/363db69b/player_ias_tce.vflset/en_US/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        '0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpz2ICs6EVdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+    ),
    (
        'https://www.youtube.com/s/player/4fcd6e4a/player_ias.vflset/en_US/base.js',
        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
        'wAOAOq0QJ8ARAIgXmPlOPSBkkUs1bYFYlJCfe29xx8q7v1pDL0QwbdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJoOySqa0',
    ),
+    (
+        'https://www.youtube.com/s/player/4fcd6e4a/player_ias_tce.vflset/en_US/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        'wAOAOq0QJ8ARAIgXmPlOPSBkkUs1bYFYlJCfe29xx8q7v1pDL0QwbdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJoOySqa0',
+    ),
+    (
+        'https://www.youtube.com/s/player/20830619/player_ias.vflset/en_US/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        '7AOq0QJ8wRAIgXmPlOPSBkkAs1bYFYlJCfe29xx8jOv1pDL0Q2bdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJoOySqa0qaw',
+    ),
+    (
+        'https://www.youtube.com/s/player/20830619/player_ias_tce.vflset/en_US/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        '7AOq0QJ8wRAIgXmPlOPSBkkAs1bYFYlJCfe29xx8jOv1pDL0Q2bdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJoOySqa0qaw',
+    ),
+    (
+        'https://www.youtube.com/s/player/20830619/player-plasma-ias-phone-en_US.vflset/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        '7AOq0QJ8wRAIgXmPlOPSBkkAs1bYFYlJCfe29xx8jOv1pDL0Q2bdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJoOySqa0qaw',
+    ),
+    (
+        'https://www.youtube.com/s/player/20830619/player-plasma-ias-tablet-en_US.vflset/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        '7AOq0QJ8wRAIgXmPlOPSBkkAs1bYFYlJCfe29xx8jOv1pDL0Q2bdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_EMu-m37KtXJoOySqa0qaw',
+    ),
+    (
+        'https://www.youtube.com/s/player/8a8ac953/player_ias_tce.vflset/en_US/base.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        'IAOAOq0QJ8wRAAgXmPlOPSBkkUs1bYFYlJCfe29xx8j7v1pDL0QwbdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_E2u-m37KtXJoOySqa0',
+    ),
+    (
+        'https://www.youtube.com/s/player/8a8ac953/tv-player-es6.vflset/tv-player-es6.js',
+        '2aq0aqSyOoJXtK73m-uME_jv7-pT15gOFC02RFkGMqWpzEICs69VdbwQ0LDp1v7j8xx92efCJlYFYb1sUkkBSPOlPmXgIARw8JQ0qOAOAA',
+        'IAOAOq0QJ8wRAAgXmPlOPSBkkUs1bYFYlJCfe29xx8j7v1pDL0QwbdV96sCIEzpWqMGkFR20CFOg51Tp-7vj_E2u-m37KtXJoOySqa0',
+    ),
 ]

 _NSIG_TESTS = [
@ -272,7 +312,7 @@ _NSIG_TESTS = [
    ),
    (
        'https://www.youtube.com/s/player/643afba4/player_ias.vflset/en_US/base.js',
-        'W9HJZKktxuYoDTqW', 'larxUlagTRAcSw',
+        'ir9-V6cdbCiyKxhr', '2PL7ZDYAALMfmA',
    ),
    (
        'https://www.youtube.com/s/player/363db69b/player_ias.vflset/en_US/base.js',
@ -286,6 +326,26 @@ _NSIG_TESTS = [
        'https://www.youtube.com/s/player/4fcd6e4a/tv-player-ias.vflset/tv-player-ias.js',
        'o_L251jm8yhZkWtBW', 'lXoxI3XvToqn6A',
    ),
+    (
+        'https://www.youtube.com/s/player/20830619/tv-player-ias.vflset/tv-player-ias.js',
+        'ir9-V6cdbCiyKxhr', '9YE85kNjZiS4',
+    ),
+    (
+        'https://www.youtube.com/s/player/20830619/player-plasma-ias-phone-en_US.vflset/base.js',
+        'ir9-V6cdbCiyKxhr', '9YE85kNjZiS4',
+    ),
+    (
+        'https://www.youtube.com/s/player/20830619/player-plasma-ias-tablet-en_US.vflset/base.js',
+        'ir9-V6cdbCiyKxhr', '9YE85kNjZiS4',
+    ),
+    (
+        'https://www.youtube.com/s/player/8a8ac953/player_ias_tce.vflset/en_US/base.js',
+        'MiBYeXx_vRREbiCCmh', 'RtZYMVvmkE0JE',
+    ),
+    (
+        'https://www.youtube.com/s/player/8a8ac953/tv-player-es6.vflset/tv-player-es6.js',
+        'MiBYeXx_vRREbiCCmh', 'RtZYMVvmkE0JE',
+    ),
 ]


@ -335,7 +395,7 @@ def t_factory(name, sig_func, url_pattern):
        test_id = re.sub(r'[/.-]', '_', m.group('id') or m.group('compat_id'))

        def test_func(self):
-            basename = 'player-{0}-{1}.js'.format(name, test_id)
+            basename = 'player-{0}.js'.format(test_id)
            fn = os.path.join(self.TESTDATA_DIR, basename)

            if not os.path.exists(fn):
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@ -1652,7 +1652,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
        assert os.path.basename(func_id) == func_id

        self.write_debug('Extracting signature function {0}'.format(func_id))
-        cache_spec, code = self.cache.load('youtube-sigfuncs', func_id), None
+        cache_spec, code = self.cache.load('youtube-sigfuncs', func_id, min_ver='2025.04.07'), None

        if not cache_spec:
            code = self._load_player(video_id, player_url, player_id)
@ -1813,6 +1813,10 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
        return ret

    def _extract_n_function_name(self, jscode):
+        func_name, idx = None, None
+        # these special cases are redundant and probably obsolete (2025-04):
+        # they make the tests run ~10% faster without fallback warnings
+        r"""
        func_name, idx = self._search_regex(
            # (y=NuD(),Mw(k),q=k.Z[y]||null)&&(q=narray[idx](q),k.set(y,q),k.V||NuD(''))}};
            # (R="nn"[+J.Z],mW(J),N=J.K[R]||null)&&(N=narray[idx](N),J.set(R,N))}};
@ -1839,9 +1843,28 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                    \(\s*[\w$]+\s*\)
            ''', jscode, 'Initial JS player n function name', group=('nfunc', 'idx'),
            default=(None, None))
+        """
+
+        if not func_name:
+            # nfunc=function(x){...}|function nfunc(x); ...
+            # ... var y=[nfunc]|y[idx]=nfunc);
+            # obvious REs hang, so use a two-stage tactic
+            for m in re.finditer(r'''(?x)
+                    [\n;]var\s(?:(?:(?!,).)+,|\s)*?(?!\d)[\w$]+(?:\[(?P<idx>\d+)\])?\s*=\s*
+                        (?(idx)|\[\s*)(?P<nfunc>(?!\d)[\w$]+)(?(idx)|\s*\])
+                    \s*?[;\n]
+                    ''', jscode):
+                func_name = self._search_regex(
+                    r'[;,]\s*(function\s+)?({0})(?(1)|\s*=\s*function)\s*\((?!\d)[\w$]+\)\s*\{1}(?!\s*return\s)'.format(
+                        re.escape(m.group('nfunc')), '{'),
+                    jscode, 'Initial JS player n function name (2)', group=2, default=None)
+                if func_name:
+                    idx = m.group('idx')
+                    break
+
        # thx bashonly: yt-dlp/yt-dlp/pull/10611
        if not func_name:
-            self.report_warning('Falling back to generic n function search')
+            self.report_warning('Falling back to generic n function search', only_once=True)
            return self._search_regex(
                r'''(?xs)
                    (?:(?<=[^\w$])|^)       # instead of \b, which ignores $
@ -1855,14 +1878,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
            return func_name

        return self._search_json(
-            r'var\s+{0}\s*='.format(re.escape(func_name)), jscode,
+            r'(?<![\w-])var\s(?:(?:(?!,).)+,|\s)*?{0}\s*='.format(re.escape(func_name)), jscode,
            'Initial JS player n function list ({0}.{1})'.format(func_name, idx),
-            func_name, contains_pattern=r'\[[\s\S]+\]', end_pattern='[,;]',
+            func_name, contains_pattern=r'\[.+\]', end_pattern='[,;]',
            transform_source=js_to_json)[int(idx)]

    def _extract_n_function_code(self, video_id, player_url):
        player_id = self._extract_player_info(player_url)
-        func_code = self.cache.load('youtube-nsig', player_id)
+        func_code = self.cache.load('youtube-nsig', player_id, min_ver='2025.04.07')
        jscode = func_code or self._load_player(video_id, player_url)
        jsi = JSInterpreter(jscode)

--- a/youtube_dl/jsinterp.py
+++ b/youtube_dl/jsinterp.py
@ -303,8 +303,6 @@ _UNARY_OPERATORS_X = (
    ('!', _js_unary_op(lambda x: _js_ternary(x, if_true=False, if_false=True))),
 )

-_OPERATOR_RE = '|'.join(map(lambda x: re.escape(x[0]), _OPERATORS + _LOG_OPERATORS))
-
 _COMP_OPERATORS = (
    ('===', _js_id_op(operator.is_)),
    ('!==', _js_id_op(operator.is_not)),
@ -316,9 +314,12 @@ _COMP_OPERATORS = (
    ('>', _js_comp_op(operator.gt)),
 )

+_OPERATOR_RE = '|'.join(map(lambda x: re.escape(x[0]), _OPERATORS + _LOG_OPERATORS + _SC_OPERATORS))
+
 _NAME_RE = r'[a-zA-Z_$][\w$]*'
 _MATCHING_PARENS = dict(zip(*zip('()', '{}', '[]')))
 _QUOTES = '\'"/'
+_NESTED_BRACKETS = r'[^[\]]+(?:\[[^[\]]+(?:\[[^\]]+\])?\])?'


 class JS_Break(ExtractorError):
@ -1088,15 +1089,18 @@ class JSInterpreter(object):

        m = re.match(r'''(?x)
            (?P<assign>
-                (?P<out>{_NAME_RE})(?:\[(?P<out_idx>(?:.+?\]\s*\[)*.+?)\])?\s*
+                (?P<out>{_NAME_RE})(?P<out_idx>(?:\[{_NESTED_BRACKETS}\])+)?\s*
                (?P<op>{_OPERATOR_RE})?
                =(?!=)(?P<expr>.*)$
            )|(?P<return>
                (?!if|return|true|false|null|undefined|NaN|Infinity)(?P<name>{_NAME_RE})$
-            )|(?P<indexing>
-                (?P<in>{_NAME_RE})\[(?P<in_idx>(?:.+?\]\s*\[)*.+?)\]$
            )|(?P<attribute>
-                (?P<var>{_NAME_RE})(?:(?P<nullish>\?)?\.(?P<member>[^(]+)|\[(?P<member2>[^\]]+)\])\s*
+                (?P<var>{_NAME_RE})(?:
+                    (?P<nullish>\?)?\.(?P<member>[^(]+)|
+                    \[(?P<member2>{_NESTED_BRACKETS})\]
+                )\s*
+            )|(?P<indexing>
+                (?P<in>{_NAME_RE})(?P<in_idx>\[.+\])$
            )|(?P<function>
                (?P<fname>{_NAME_RE})\((?P<args>.*)\)$
            )'''.format(**globals()), expr)
@ -1111,10 +1115,11 @@ class JSInterpreter(object):
            elif left_val in (None, JS_Undefined):
                raise self.Exception('Cannot index undefined variable ' + m.group('out'), expr=expr)

-            indexes = re.split(r'\]\s*\[', m.group('out_idx'))
-            for i, idx in enumerate(indexes, 1):
+            indexes = md['out_idx']
+            while indexes:
+                idx, indexes = self._separate_at_paren(indexes)
                idx = self.interpret_expression(idx, local_vars, allow_recursion)
-                if i < len(indexes):
+                if indexes:
                    left_val = self._index(left_val, idx)
            if isinstance(idx, float):
                idx = int(idx)
@ -1159,7 +1164,9 @@ class JSInterpreter(object):

        if md.get('indexing'):
            val = local_vars[m.group('in')]
-            for idx in re.split(r'\]\s*\[', m.group('in_idx')):
+            indexes = m.group('in_idx')
+            while indexes:
+                idx, indexes = self._separate_at_paren(indexes)
                idx = self.interpret_expression(idx, local_vars, allow_recursion)
                val = self._index(val, idx)
            return val, should_return
@ -1204,7 +1211,7 @@ class JSInterpreter(object):
                if obj is JS_Undefined:
                    try:
                        if variable not in self._objects:
-                            self._objects[variable] = self.extract_object(variable)
+                            self._objects[variable] = self.extract_object(variable, local_vars)
                        obj = self._objects[variable]
                    except self.Exception:
                        if not nullish:
@ -1215,7 +1222,7 @@ class JSInterpreter(object):

                # Member access
                if arg_str is None:
-                    return self._index(obj, member)
+                    return self._index(obj, member, nullish)

                # Function call
                argvals = [
@ -1400,7 +1407,7 @@ class JSInterpreter(object):
        for v in self._separate(list_txt):
            yield self.interpret_expression(v, local_vars, allow_recursion)

-    def extract_object(self, objname):
+    def extract_object(self, objname, *global_stack):
        _FUNC_NAME_RE = r'''(?:{n}|"{n}"|'{n}')'''.format(n=_NAME_RE)
        obj = {}
        fields = next(filter(None, (
@ -1421,7 +1428,8 @@ class JSInterpreter(object):
                fields):
            argnames = self.build_arglist(f.group('args'))
            name = remove_quotes(f.group('key'))
-            obj[name] = function_with_repr(self.build_function(argnames, f.group('code')), 'F<{0}>'.format(name))
+            obj[name] = function_with_repr(
+                self.build_function(argnames, f.group('code'), *global_stack), 'F<{0}>'.format(name))

        return obj

--- a/youtube_dl/version.py
+++ b/youtube_dl/version.py
@ -1,3 +1,3 @@
 from __future__ import unicode_literals

-__version__ = '2021.12.17'
+__version__ = '2025.04.07'