test/test_jsinterp.py

@@ -490,52 +490,6 @@ class TestJSInterpreter(unittest.TestCase):
         self._test('function f() { var a = "test--"; return a; }', 'test--')
         self._test('function f() { var b = 1; var a = "b--"; return a; }', 'b--')
 
-    def test_nested_function_scoping(self):
-        self._test(R'''
-            function f() {
-                var g = function() {
-                    var P = 2;
-                    return P;
-                };
-                var P = 1;
-                g();
-                return P;
-            }
-        ''', 1)
-        self._test(R'''
-            function f() {
-                var x = function() {
-                    for (var w = 1, M = []; w < 2; w++) switch (w) {
-                        case 1:
-                            M.push("a");
-                        case 2:
-                            M.push("b");
-                    }
-                    return M
-                };
-                var w = "c";
-                var M = "d";
-                var y = x();
-                y.push(w);
-                y.push(M);
-                return y;
-            }
-        ''', ['a', 'b', 'c', 'd'])
-        self._test(R'''
-            function f() {
-                var P, Q;
-                var z = 100;
-                var g = function() {
-                    var P, Q; P = 2; Q = 15;
-                    z = 0;
-                    return P+Q;
-                };
-                P = 1; Q = 10;
-                var x = g(), y = 3;
-                return P+Q+x+y+z;
-            }
-        ''', 31)
-
 
 if __name__ == '__main__':
     unittest.main()

test/test_youtube_signature.py

@@ -333,46 +333,6 @@ _NSIG_TESTS = [
         'https://www.youtube.com/s/player/fc2a56a5/tv-player-ias.vflset/tv-player-ias.js',
         'qTKWg_Il804jd2kAC', 'OtUAm2W6gyzJjB9u',
     ),
-    (
-        'https://www.youtube.com/s/player/a74bf670/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', 'hQP7k1hA22OrNTnq',
-    ),
-    (
-        'https://www.youtube.com/s/player/6275f73c/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', '-I03XF0iyf6I_X0A',
-    ),
-    (
-        'https://www.youtube.com/s/player/20c72c18/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', '-I03XF0iyf6I_X0A',
-    ),
-    (
-        'https://www.youtube.com/s/player/9fe2e06e/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', '6r5ekNIiEMPutZy',
-    ),
-    (
-        'https://www.youtube.com/s/player/680f8c75/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', '0ml9caTwpa55Jf',
-    ),
-    (
-        'https://www.youtube.com/s/player/14397202/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', 'ozZFAN21okDdJTa',
-    ),
-    (
-        'https://www.youtube.com/s/player/5dcb2c1f/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', 'p7iTbRZDYAF',
-    ),
-    (
-        'https://www.youtube.com/s/player/a10d7fcc/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', '9Zue7DDHJSD',
-    ),
-    (
-        'https://www.youtube.com/s/player/8e20cb06/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', '5-4tTneTROTpMzba',
-    ),
-    (
-        'https://www.youtube.com/s/player/e12fbea4/player_ias_tce.vflset/en_US/base.js',
-        'kM5r52fugSZRAKHfo3', 'XkeRfXIPOkSwfg',
-    ),
 ]
 
 

yt_dlp/extractor/youtube/_video.py

@@ -26,7 +26,7 @@ from ._base import (
 from .pot._director import initialize_pot_director
 from .pot.provider import PoTokenContext, PoTokenRequest
 from ..openload import PhantomJSwrapper
-from ...jsinterp import JSInterpreter, LocalNameSpace
+from ...jsinterp import JSInterpreter
 from ...networking.exceptions import HTTPError
 from ...utils import (
     NO_DEFAULT,
@@ -1801,8 +1801,6 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
         'tablet': 'player-plasma-ias-tablet-en_US.vflset/base.js',
     }
     _INVERSE_PLAYER_JS_VARIANT_MAP = {v: k for k, v in _PLAYER_JS_VARIANT_MAP.items()}
-    _NSIG_FUNC_CACHE_ID = 'nsig func'
-    _DUMMY_STRING = 'dlp_wins'
 
     @classmethod
     def suitable(cls, url):
@@ -2206,7 +2204,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             self.to_screen(f'Extracted nsig function from {player_id}:\n{func_code[1]}\n')
 
         try:
-            extract_nsig = self._cached(self._extract_n_function_from_code, self._NSIG_FUNC_CACHE_ID, player_url)
+            extract_nsig = self._cached(self._extract_n_function_from_code, 'nsig func', player_url)
             ret = extract_nsig(jsi, func_code)(s)
         except JSInterpreter.Exception as e:
             try:
@@ -2314,18 +2312,16 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
 
         jsi = JSInterpreter(varcode)
         interpret_global_var = self._cached(jsi.interpret_expression, 'js global list', player_url)
-        return varname, interpret_global_var(varvalue, LocalNameSpace(), allow_recursion=10)
+        return varname, interpret_global_var(varvalue, {}, allow_recursion=10)
 
     def _fixup_n_function_code(self, argnames, nsig_code, jscode, player_url):
-        # Fixup global array
         varname, global_list = self._interpret_player_js_global_var(jscode, player_url)
         if varname and global_list:
             nsig_code = f'var {varname}={json.dumps(global_list)}; {nsig_code}'
         else:
-            varname = self._DUMMY_STRING
+            varname = 'dlp_wins'
             global_list = []
 
-        # Fixup typeof check
         undefined_idx = global_list.index('undefined') if 'undefined' in global_list else r'\d+'
         fixed_code = re.sub(
             fr'''(?x)
@@ -2338,32 +2334,6 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             self.write_debug(join_nonempty(
                 'No typeof statement found in nsig function code',
                 player_url and f'        player = {player_url}', delim='\n'), only_once=True)
-
-        # Fixup global funcs
-        jsi = JSInterpreter(fixed_code)
-        cache_id = (self._NSIG_FUNC_CACHE_ID, player_url)
-        try:
-            self._cached(
-                self._extract_n_function_from_code, *cache_id)(jsi, (argnames, fixed_code))(self._DUMMY_STRING)
-        except JSInterpreter.Exception:
-            self._player_cache.pop(cache_id, None)
-
-        global_funcnames = jsi._undefined_varnames
-        debug_names = []
-        jsi = JSInterpreter(jscode)
-        for func_name in global_funcnames:
-            try:
-                func_args, func_code = jsi.extract_function_code(func_name)
-                fixed_code = f'var {func_name} = function({", ".join(func_args)}) {{ {func_code} }}; {fixed_code}'
-                debug_names.append(func_name)
-            except Exception:
-                self.report_warning(join_nonempty(
-                    f'Unable to extract global nsig function {func_name} from player JS',
-                    player_url and f'        player = {player_url}', delim='\n'), only_once=True)
-
-        if debug_names:
-            self.write_debug(f'Extracted global nsig functions: {", ".join(debug_names)}')
-
         return argnames, fixed_code
 
     def _extract_n_function_code(self, video_id, player_url):
@@ -2377,7 +2347,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
 
         func_name = self._extract_n_function_name(jscode, player_url=player_url)
 
-        # XXX: Work around (a) global array variable, (b) `typeof` short-circuit, (c) global functions
+        # XXX: Workaround for the global array variable and lack of `typeof` implementation
         func_code = self._fixup_n_function_code(*jsi.extract_function_code(func_name), jscode, player_url)
 
         return jsi, player_id, func_code

yt_dlp/jsinterp.py

@@ -222,14 +222,6 @@ class LocalNameSpace(collections.ChainMap):
     def __delitem__(self, key):
         raise NotImplementedError('Deleting is not supported')
 
-    def set_local(self, key, value):
-        self.maps[0][key] = value
-
-    def get_local(self, key):
-        if key in self.maps[0]:
-            return self.maps[0][key]
-        return JS_Undefined
-
 
 class Debugger:
     import sys
@@ -279,7 +271,6 @@ class JSInterpreter:
     def __init__(self, code, objects=None):
         self.code, self._functions = code, {}
         self._objects = {} if objects is None else objects
-        self._undefined_varnames = set()
 
     class Exception(ExtractorError):  # noqa: A001
         def __init__(self, msg, expr=None, *args, **kwargs):
@@ -390,7 +381,7 @@ class JSInterpreter:
             return self._named_object(namespace, obj)
 
     @Debugger.wrap_interpreter
-    def interpret_statement(self, stmt, local_vars, allow_recursion=100, _is_var_declaration=False):
+    def interpret_statement(self, stmt, local_vars, allow_recursion=100):
         if allow_recursion < 0:
             raise self.Exception('Recursion limit reached')
         allow_recursion -= 1
@@ -410,7 +401,6 @@ class JSInterpreter:
             if m.group('throw'):
                 raise JS_Throw(self.interpret_expression(expr, local_vars, allow_recursion))
             should_return = not m.group('var')
-            _is_var_declaration = _is_var_declaration or bool(m.group('var'))
         if not expr:
             return None, should_return
 
@@ -595,8 +585,7 @@ class JSInterpreter:
         sub_expressions = list(self._separate(expr))
         if len(sub_expressions) > 1:
             for sub_expr in sub_expressions:
-                ret, should_abort = self.interpret_statement(
+                ret, should_abort = self.interpret_statement(sub_expr, local_vars, allow_recursion)
-                    sub_expr, local_vars, allow_recursion, _is_var_declaration=_is_var_declaration)
                 if should_abort:
                     return ret, True
             return ret, False
@@ -610,12 +599,8 @@ class JSInterpreter:
             left_val = local_vars.get(m.group('out'))
 
             if not m.group('index'):
-                eval_result = self._operator(
+                local_vars[m.group('out')] = self._operator(
                     m.group('op'), left_val, m.group('expr'), expr, local_vars, allow_recursion)
-                if _is_var_declaration:
-                    local_vars.set_local(m.group('out'), eval_result)
-                else:
-                    local_vars[m.group('out')] = eval_result
                 return local_vars[m.group('out')], should_return
             elif left_val in (None, JS_Undefined):
                 raise self.Exception(f'Cannot index undefined variable {m.group("out")}', expr)
@@ -669,18 +654,7 @@ class JSInterpreter:
             return float('NaN'), should_return
 
         elif m and m.group('return'):
-            var = m.group('name')
+            return local_vars.get(m.group('name'), JS_Undefined), should_return
-            # Declared variables
-            if _is_var_declaration:
-                ret = local_vars.get_local(var)
-                # Register varname in local namespace
-                # Set value as JS_Undefined or its pre-existing value
-                local_vars.set_local(var, ret)
-            else:
-                ret = local_vars.get(var, JS_Undefined)
-                if ret is JS_Undefined:
-                    self._undefined_varnames.add(var)
-            return ret, should_return
 
         with contextlib.suppress(ValueError):
             return json.loads(js_to_json(expr, strict=True)), should_return