-from collections.abc import MutableMapping
+import collections
+import contextlib
+import itertools
import json
+import math
import operator
import re
from .utils import (
+ NO_DEFAULT,
ExtractorError,
+ function_with_repr,
+ js_to_json,
remove_quotes,
+ truncate_string,
+ unified_timestamp,
+ write_string,
)
-_OPERATORS = [
- ('|', operator.or_),
- ('^', operator.xor),
- ('&', operator.and_),
- ('>>', operator.rshift),
- ('<<', operator.lshift),
- ('-', operator.sub),
- ('+', operator.add),
- ('%', operator.mod),
- ('/', operator.truediv),
- ('*', operator.mul),
-]
-_ASSIGN_OPERATORS = [(op + '=', opfunc) for op, opfunc in _OPERATORS]
-_ASSIGN_OPERATORS.append(('=', (lambda cur, right: right)))
-_NAME_RE = r'[a-zA-Z_$][a-zA-Z_$0-9]*'
+def _js_bit_op(op):
+ def zeroise(x):
+ if x in (None, JS_Undefined):
+ return 0
+ with contextlib.suppress(TypeError):
+ if math.isnan(x): # NB: NaN cannot be checked by membership
+ return 0
+ return x
-_MATCHING_PARENS = dict(zip('({[', ')}]'))
+ def wrapped(a, b):
+ return op(zeroise(a), zeroise(b)) & 0xffffffff
+
+ return wrapped
+
+
+def _js_arith_op(op):
+
+ def wrapped(a, b):
+ if JS_Undefined in (a, b):
+ return float('nan')
+ return op(a or 0, b or 0)
+
+ return wrapped
+
+
+def _js_div(a, b):
+ if JS_Undefined in (a, b) or not (a or b):
+ return float('nan')
+ return (a or 0) / b if b else float('inf')
+
+
+def _js_mod(a, b):
+ if JS_Undefined in (a, b) or not b:
+ return float('nan')
+ return (a or 0) % b
+
+
+def _js_exp(a, b):
+ if not b:
+ return 1 # even 0 ** 0 !!
+ elif JS_Undefined in (a, b):
+ return float('nan')
+ return (a or 0) ** b
+
+
+def _js_eq_op(op):
+
+ def wrapped(a, b):
+ if {a, b} <= {None, JS_Undefined}:
+ return op(a, a)
+ return op(a, b)
+
+ return wrapped
+
+
+def _js_comp_op(op):
+
+ def wrapped(a, b):
+ if JS_Undefined in (a, b):
+ return False
+ if isinstance(a, str) or isinstance(b, str):
+ return op(str(a or 0), str(b or 0))
+ return op(a or 0, b or 0)
+
+ return wrapped
+
+
+def _js_ternary(cndn, if_true=True, if_false=False):
+ """Simulate JS's ternary operator (cndn?if_true:if_false)"""
+ if cndn in (False, None, 0, '', JS_Undefined):
+ return if_false
+ with contextlib.suppress(TypeError):
+ if math.isnan(cndn): # NB: NaN cannot be checked by membership
+ return if_false
+ return if_true
+
+
+# Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence
+_OPERATORS = { # None => Defined in JSInterpreter._operator
+ '?': None,
+ '??': None,
+ '||': None,
+ '&&': None,
+
+ '|': _js_bit_op(operator.or_),
+ '^': _js_bit_op(operator.xor),
+ '&': _js_bit_op(operator.and_),
+
+ '===': operator.is_,
+ '!==': operator.is_not,
+ '==': _js_eq_op(operator.eq),
+ '!=': _js_eq_op(operator.ne),
+
+ '<=': _js_comp_op(operator.le),
+ '>=': _js_comp_op(operator.ge),
+ '<': _js_comp_op(operator.lt),
+ '>': _js_comp_op(operator.gt),
+
+ '>>': _js_bit_op(operator.rshift),
+ '<<': _js_bit_op(operator.lshift),
+
+ '+': _js_arith_op(operator.add),
+ '-': _js_arith_op(operator.sub),
+
+ '*': _js_arith_op(operator.mul),
+ '%': _js_mod,
+ '/': _js_div,
+ '**': _js_exp,
+}
+
+_COMP_OPERATORS = {'===', '!==', '==', '!=', '<=', '>=', '<', '>'}
+
+_NAME_RE = r'[a-zA-Z_$][\w$]*'
+_MATCHING_PARENS = dict(zip(*zip('()', '{}', '[]')))
+_QUOTES = '\'"/'
+
+
+class JS_Undefined:
+ pass
class JS_Break(ExtractorError):
ExtractorError.__init__(self, 'Invalid continue')
-class LocalNameSpace(MutableMapping):
- def __init__(self, *stack):
- self.stack = tuple(stack)
+class JS_Throw(ExtractorError):
+ def __init__(self, e):
+ self.error = e
+ ExtractorError.__init__(self, f'Uncaught exception {e}')
- def __getitem__(self, key):
- for scope in self.stack:
- if key in scope:
- return scope[key]
- raise KeyError(key)
+class LocalNameSpace(collections.ChainMap):
def __setitem__(self, key, value):
- for scope in self.stack:
+ for scope in self.maps:
if key in scope:
scope[key] = value
- break
- else:
- self.stack[0][key] = value
- return value
+ return
+ self.maps[0][key] = value
def __delitem__(self, key):
raise NotImplementedError('Deleting is not supported')
- def __iter__(self):
- for scope in self.stack:
- yield from scope
-
- def __len__(self, key):
- return len(iter(self))
- def __repr__(self):
- return f'LocalNameSpace{self.stack}'
+class Debugger:
+ import sys
+ ENABLED = False and 'pytest' in sys.modules
+ @staticmethod
+ def write(*args, level=100):
+ write_string(f'[debug] JS: {" " * (100 - level)}'
+ f'{" ".join(truncate_string(str(x), 50, 50) for x in args)}\n')
+
+ @classmethod
+ def wrap_interpreter(cls, f):
+ def interpret_statement(self, stmt, local_vars, allow_recursion, *args, **kwargs):
+ if cls.ENABLED and stmt.strip():
+ cls.write(stmt, level=allow_recursion)
+ try:
+ ret, should_ret = f(self, stmt, local_vars, allow_recursion, *args, **kwargs)
+ except Exception as e:
+ if cls.ENABLED:
+ if isinstance(e, ExtractorError):
+ e = e.orig_msg
+ cls.write('=> Raises:', e, '<-|', stmt, level=allow_recursion)
+ raise
+ if cls.ENABLED and stmt.strip():
+ if should_ret or repr(ret) != stmt:
+ cls.write(['->', '=>'][should_ret], repr(ret), '<-|', stmt, level=allow_recursion)
+ return ret, should_ret
+ return interpret_statement
+
+
+class JSInterpreter:
+ __named_object_counter = 0
+
+ _RE_FLAGS = {
+ # special knowledge: Python's re flags are bitmask values, current max 128
+ # invent new bitmask values well above that for literal parsing
+ # TODO: new pattern class to execute matches with these flags
+ 'd': 1024, # Generate indices for substring matches
+ 'g': 2048, # Global search
+ 'i': re.I, # Case-insensitive search
+ 'm': re.M, # Multi-line search
+ 's': re.S, # Allows . to match newline characters
+ 'u': re.U, # Treat a pattern as a sequence of unicode code points
+ 'y': 4096, # Perform a "sticky" search that matches starting at the current position in the target string
+ }
-class JSInterpreter(object):
def __init__(self, code, objects=None):
- if objects is None:
- objects = {}
- self.code = code
- self._functions = {}
- self._objects = objects
- self.__named_object_counter = 0
+ self.code, self._functions = code, {}
+ self._objects = {} if objects is None else objects
+
+ class Exception(ExtractorError): # noqa: A001
+ def __init__(self, msg, expr=None, *args, **kwargs):
+ if expr is not None:
+ msg = f'{msg.rstrip()} in: {truncate_string(expr, 50, 50)}'
+ super().__init__(msg, *args, **kwargs)
def _named_object(self, namespace, obj):
self.__named_object_counter += 1
name = f'__yt_dlp_jsinterp_obj{self.__named_object_counter}'
+ if callable(obj) and not isinstance(obj, function_with_repr):
+ obj = function_with_repr(obj, f'F<{self.__named_object_counter}>')
namespace[name] = obj
return name
+ @classmethod
+ def _regex_flags(cls, expr):
+ flags = 0
+ if not expr:
+ return flags, expr
+ for idx, ch in enumerate(expr): # noqa: B007
+ if ch not in cls._RE_FLAGS:
+ break
+ flags |= cls._RE_FLAGS[ch]
+ return flags, expr[idx + 1:]
+
@staticmethod
- def _seperate(expr, delim=',', max_split=None):
+ def _separate(expr, delim=',', max_split=None):
+ OP_CHARS = '+-*/%&|^=<>!,;{}:['
if not expr:
return
counters = {k: 0 for k in _MATCHING_PARENS.values()}
start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1
+ in_quote, escaping, after_op, in_regex_char_group = None, False, True, False
for idx, char in enumerate(expr):
- if char in _MATCHING_PARENS:
+ if not in_quote and char in _MATCHING_PARENS:
counters[_MATCHING_PARENS[char]] += 1
- elif char in counters:
- counters[char] -= 1
- if char != delim[pos] or any(counters.values()):
+ elif not in_quote and char in counters:
+ # Something's wrong if we get negative, but ignore it anyway
+ if counters[char]:
+ counters[char] -= 1
+ elif not escaping:
+ if char in _QUOTES and in_quote in (char, None):
+ if in_quote or after_op or char != '/':
+ in_quote = None if in_quote and not in_regex_char_group else char
+ elif in_quote == '/' and char in '[]':
+ in_regex_char_group = char == '['
+ escaping = not escaping and in_quote and char == '\\'
+ in_unary_op = (not in_quote and not in_regex_char_group
+ and after_op not in (True, False) and char in '-+')
+ after_op = char if (not in_quote and char in OP_CHARS) else (char.isspace() and after_op)
+
+ if char != delim[pos] or any(counters.values()) or in_quote or in_unary_op:
pos = 0
continue
elif pos != delim_len:
break
yield expr[start:]
- @staticmethod
- def _seperate_at_paren(expr, delim):
- seperated = list(JSInterpreter._seperate(expr, delim, 1))
- if len(seperated) < 2:
- raise ExtractorError(f'No terminating paren {delim} in {expr}')
- return seperated[0][1:].strip(), seperated[1].strip()
+ @classmethod
+ def _separate_at_paren(cls, expr, delim=None):
+ if delim is None:
+ delim = expr and _MATCHING_PARENS[expr[0]]
+ separated = list(cls._separate(expr, delim, 1))
+ if len(separated) < 2:
+ raise cls.Exception(f'No terminating paren {delim}', expr)
+ return separated[0][1:].strip(), separated[1].strip()
+
+ def _operator(self, op, left_val, right_expr, expr, local_vars, allow_recursion):
+ if op in ('||', '&&'):
+ if (op == '&&') ^ _js_ternary(left_val):
+ return left_val # short circuiting
+ elif op == '??':
+ if left_val not in (None, JS_Undefined):
+ return left_val
+ elif op == '?':
+ right_expr = _js_ternary(left_val, *self._separate(right_expr, ':', 1))
+
+ right_val = self.interpret_expression(right_expr, local_vars, allow_recursion)
+ if not _OPERATORS.get(op):
+ return right_val
+
+ try:
+ return _OPERATORS[op](left_val, right_val)
+ except Exception as e:
+ raise self.Exception(f'Failed to evaluate {left_val!r} {op} {right_val!r}', expr, cause=e)
+
+ def _index(self, obj, idx, allow_undefined=False):
+ if idx == 'length':
+ return len(obj)
+ try:
+ return obj[int(idx)] if isinstance(obj, list) else obj[idx]
+ except Exception as e:
+ if allow_undefined:
+ return JS_Undefined
+ raise self.Exception(f'Cannot get index {idx}', repr(obj), cause=e)
+
+ def _dump(self, obj, namespace):
+ try:
+ return json.dumps(obj)
+ except TypeError:
+ return self._named_object(namespace, obj)
+ @Debugger.wrap_interpreter
def interpret_statement(self, stmt, local_vars, allow_recursion=100):
if allow_recursion < 0:
- raise ExtractorError('Recursion limit reached')
+ raise self.Exception('Recursion limit reached')
+ allow_recursion -= 1
+
+ should_return = False
+ sub_statements = list(self._separate(stmt, ';')) or ['']
+ expr = stmt = sub_statements.pop().strip()
- sub_statements = list(self._seperate(stmt, ';'))
- stmt = (sub_statements or ['']).pop()
for sub_stmt in sub_statements:
- ret, should_abort = self.interpret_statement(sub_stmt, local_vars, allow_recursion - 1)
- if should_abort:
- return ret
+ ret, should_return = self.interpret_statement(sub_stmt, local_vars, allow_recursion)
+ if should_return:
+ return ret, should_return
- should_abort = False
- stmt = stmt.lstrip()
- stmt_m = re.match(r'var\s', stmt)
- if stmt_m:
- expr = stmt[len(stmt_m.group(0)):]
- else:
- return_m = re.match(r'return(?:\s+|$)', stmt)
- if return_m:
- expr = stmt[len(return_m.group(0)):]
- should_abort = True
+ m = re.match(r'(?P<var>(?:var|const|let)\s)|return(?:\s+|(?=["\'])|$)|(?P<throw>throw\s+)', stmt)
+ if m:
+ expr = stmt[len(m.group(0)):].strip()
+ if m.group('throw'):
+ raise JS_Throw(self.interpret_expression(expr, local_vars, allow_recursion))
+ should_return = not m.group('var')
+ if not expr:
+ return None, should_return
+
+ if expr[0] in _QUOTES:
+ inner, outer = self._separate(expr, expr[0], 1)
+ if expr[0] == '/':
+ flags, outer = self._regex_flags(outer)
+ # We don't support regex methods yet, so no point compiling it
+ inner = f'{inner}/{flags}'
+ # Avoid https://github.com/python/cpython/issues/74534
+ # inner = re.compile(inner[1:].replace('[[', r'[\['), flags=flags)
else:
- # Try interpreting it as an expression
- expr = stmt
-
- v = self.interpret_expression(expr, local_vars, allow_recursion)
- return v, should_abort
+ inner = json.loads(js_to_json(f'{inner}{expr[0]}', strict=True))
+ if not outer:
+ return inner, should_return
+ expr = self._named_object(local_vars, inner) + outer
+
+ if expr.startswith('new '):
+ obj = expr[4:]
+ if obj.startswith('Date('):
+ left, right = self._separate_at_paren(obj[4:])
+ date = unified_timestamp(
+ self.interpret_expression(left, local_vars, allow_recursion), False)
+ if date is None:
+ raise self.Exception(f'Failed to parse date {left!r}', expr)
+ expr = self._dump(int(date * 1000), local_vars) + right
+ else:
+ raise self.Exception(f'Unsupported object {obj}', expr)
- def interpret_expression(self, expr, local_vars, allow_recursion):
- expr = expr.strip()
- if expr == '': # Empty expression
- return None
+ if expr.startswith('void '):
+ left = self.interpret_expression(expr[5:], local_vars, allow_recursion)
+ return None, should_return
if expr.startswith('{'):
- inner, outer = self._seperate_at_paren(expr, '}')
- inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion - 1)
+ inner, outer = self._separate_at_paren(expr)
+ # try for object expression (Map)
+ sub_expressions = [list(self._separate(sub_expr.strip(), ':', 1)) for sub_expr in self._separate(inner)]
+ if all(len(sub_expr) == 2 for sub_expr in sub_expressions):
+ def dict_item(key, val):
+ val = self.interpret_expression(val, local_vars, allow_recursion)
+ if re.match(_NAME_RE, key):
+ return key, val
+ return self.interpret_expression(key, local_vars, allow_recursion), val
+
+ return dict(dict_item(k, v) for k, v in sub_expressions), should_return
+
+ inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion)
if not outer or should_abort:
- return inner
+ return inner, should_abort or should_return
else:
- expr = json.dumps(inner) + outer
+ expr = self._dump(inner, local_vars) + outer
if expr.startswith('('):
- inner, outer = self._seperate_at_paren(expr, ')')
- inner = self.interpret_expression(inner, local_vars, allow_recursion)
- if not outer:
- return inner
+ inner, outer = self._separate_at_paren(expr)
+ inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion)
+ if not outer or should_abort:
+ return inner, should_abort or should_return
else:
- expr = json.dumps(inner) + outer
+ expr = self._dump(inner, local_vars) + outer
if expr.startswith('['):
- inner, outer = self._seperate_at_paren(expr, ']')
+ inner, outer = self._separate_at_paren(expr)
name = self._named_object(local_vars, [
self.interpret_expression(item, local_vars, allow_recursion)
- for item in self._seperate(inner)])
+ for item in self._separate(inner)])
expr = name + outer
- m = re.match(r'try\s*', expr)
- if m:
- if expr[m.end()] == '{':
- try_expr, expr = self._seperate_at_paren(expr[m.end():], '}')
- else:
- try_expr, expr = expr[m.end() - 1:], ''
- ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion - 1)
+ m = re.match(r'''(?x)
+ (?P<try>try)\s*\{|
+ (?P<if>if)\s*\(|
+ (?P<switch>switch)\s*\(|
+ (?P<for>for)\s*\(
+ ''', expr)
+ md = m.groupdict() if m else {}
+ if md.get('if'):
+ cndn, expr = self._separate_at_paren(expr[m.end() - 1:])
+ if_expr, expr = self._separate_at_paren(expr.lstrip())
+ # TODO: "else if" is not handled
+ else_expr = None
+ m = re.match(r'else\s*{', expr)
+ if m:
+ else_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
+ cndn = _js_ternary(self.interpret_expression(cndn, local_vars, allow_recursion))
+ ret, should_abort = self.interpret_statement(
+ if_expr if cndn else else_expr, local_vars, allow_recursion)
if should_abort:
- return ret
- return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
+ return ret, True
- m = re.match(r'catch\s*\(', expr)
- if m:
- # We ignore the catch block
- _, expr = self._seperate_at_paren(expr, '}')
- return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
+ if md.get('try'):
+ try_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
+ err = None
+ try:
+ ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion)
+ if should_abort:
+ return ret, True
+ except Exception as e:
+ # XXX: This works for now, but makes debugging future issues very hard
+ err = e
+
+ pending = (None, False)
+ m = re.match(fr'catch\s*(?P<err>\(\s*{_NAME_RE}\s*\))?\{{', expr)
+ if m:
+ sub_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
+ if err:
+ catch_vars = {}
+ if m.group('err'):
+ catch_vars[m.group('err')] = err.error if isinstance(err, JS_Throw) else err
+ catch_vars = local_vars.new_child(catch_vars)
+ err, pending = None, self.interpret_statement(sub_expr, catch_vars, allow_recursion)
+
+ m = re.match(r'finally\s*\{', expr)
+ if m:
+ sub_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
+ ret, should_abort = self.interpret_statement(sub_expr, local_vars, allow_recursion)
+ if should_abort:
+ return ret, True
- m = re.match(r'for\s*\(', expr)
- if m:
- constructor, remaining = self._seperate_at_paren(expr[m.end() - 1:], ')')
+ ret, should_abort = pending
+ if should_abort:
+ return ret, True
+
+ if err:
+ raise err
+
+ elif md.get('for'):
+ constructor, remaining = self._separate_at_paren(expr[m.end() - 1:])
if remaining.startswith('{'):
- body, expr = self._seperate_at_paren(remaining, '}')
+ body, expr = self._separate_at_paren(remaining)
else:
- m = re.match(r'switch\s*\(', remaining) # FIXME
- if m:
- switch_val, remaining = self._seperate_at_paren(remaining[m.end() - 1:], ')')
- body, expr = self._seperate_at_paren(remaining, '}')
+ switch_m = re.match(r'switch\s*\(', remaining) # FIXME: ?
+ if switch_m:
+ switch_val, remaining = self._separate_at_paren(remaining[switch_m.end() - 1:])
+ body, expr = self._separate_at_paren(remaining, '}')
body = 'switch(%s){%s}' % (switch_val, body)
else:
body, expr = remaining, ''
- start, cndn, increment = self._seperate(constructor, ';')
- if self.interpret_statement(start, local_vars, allow_recursion - 1)[1]:
- raise ExtractorError(
- f'Premature return in the initialization of a for loop in {constructor!r}')
+ start, cndn, increment = self._separate(constructor, ';')
+ self.interpret_expression(start, local_vars, allow_recursion)
while True:
- if not self.interpret_expression(cndn, local_vars, allow_recursion):
+ if not _js_ternary(self.interpret_expression(cndn, local_vars, allow_recursion)):
break
try:
- ret, should_abort = self.interpret_statement(body, local_vars, allow_recursion - 1)
+ ret, should_abort = self.interpret_statement(body, local_vars, allow_recursion)
if should_abort:
- return ret
+ return ret, True
except JS_Break:
break
except JS_Continue:
pass
- if self.interpret_statement(increment, local_vars, allow_recursion - 1)[1]:
- raise ExtractorError(
- f'Premature return in the initialization of a for loop in {constructor!r}')
- return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
+ self.interpret_expression(increment, local_vars, allow_recursion)
- m = re.match(r'switch\s*\(', expr)
- if m:
- switch_val, remaining = self._seperate_at_paren(expr[m.end() - 1:], ')')
+ elif md.get('switch'):
+ switch_val, remaining = self._separate_at_paren(expr[m.end() - 1:])
switch_val = self.interpret_expression(switch_val, local_vars, allow_recursion)
- body, expr = self._seperate_at_paren(remaining, '}')
+ body, expr = self._separate_at_paren(remaining, '}')
items = body.replace('default:', 'case default:').split('case ')[1:]
for default in (False, True):
matched = False
for item in items:
- case, stmt = [i.strip() for i in self._seperate(item, ':', 1)]
+ case, stmt = (i.strip() for i in self._separate(item, ':', 1))
if default:
matched = matched or case == 'default'
elif not matched:
- matched = case != 'default' and switch_val == self.interpret_expression(case, local_vars, allow_recursion)
+ matched = (case != 'default'
+ and switch_val == self.interpret_expression(case, local_vars, allow_recursion))
if not matched:
continue
try:
- ret, should_abort = self.interpret_statement(stmt, local_vars, allow_recursion - 1)
+ ret, should_abort = self.interpret_statement(stmt, local_vars, allow_recursion)
if should_abort:
return ret
except JS_Break:
break
if matched:
break
- return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
- # Comma seperated statements
- sub_expressions = list(self._seperate(expr))
- expr = sub_expressions.pop().strip() if sub_expressions else ''
- for sub_expr in sub_expressions:
- self.interpret_expression(sub_expr, local_vars, allow_recursion)
+ if md:
+ ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion)
+ return ret, should_abort or should_return
+
+ # Comma separated statements
+ sub_expressions = list(self._separate(expr))
+ if len(sub_expressions) > 1:
+ for sub_expr in sub_expressions:
+ ret, should_abort = self.interpret_statement(sub_expr, local_vars, allow_recursion)
+ if should_abort:
+ return ret, True
+ return ret, False
for m in re.finditer(rf'''(?x)
(?P<pre_sign>\+\+|--)(?P<var1>{_NAME_RE})|
local_vars[var] += 1 if sign[0] == '+' else -1
if m.group('pre_sign'):
ret = local_vars[var]
- expr = expr[:start] + json.dumps(ret) + expr[end:]
-
- for op, opfunc in _ASSIGN_OPERATORS:
- m = re.match(r'''(?x)
- (?P<out>%s)(?:\[(?P<index>[^\]]+?)\])?
- \s*%s
- (?P<expr>.*)$''' % (_NAME_RE, re.escape(op)), expr)
- if not m:
- continue
- right_val = self.interpret_expression(m.group('expr'), local_vars, allow_recursion)
-
- if m.groupdict().get('index'):
- lvar = local_vars[m.group('out')]
- idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion)
- if not isinstance(idx, int):
- raise ExtractorError(f'List indices must be integers: {idx}')
- cur = lvar[idx]
- val = opfunc(cur, right_val)
- lvar[idx] = val
- return val
- else:
- cur = local_vars.get(m.group('out'))
- val = opfunc(cur, right_val)
- local_vars[m.group('out')] = val
- return val
-
- if expr.isdigit():
- return int(expr)
+ expr = expr[:start] + self._dump(ret, local_vars) + expr[end:]
- if expr == 'break':
- raise JS_Break()
+ if not expr:
+ return None, should_return
+
+ m = re.match(fr'''(?x)
+ (?P<assign>
+ (?P<out>{_NAME_RE})(?:\[(?P<index>[^\]]+?)\])?\s*
+ (?P<op>{"|".join(map(re.escape, set(_OPERATORS) - _COMP_OPERATORS))})?
+ =(?!=)(?P<expr>.*)$
+ )|(?P<return>
+ (?!if|return|true|false|null|undefined|NaN)(?P<name>{_NAME_RE})$
+ )|(?P<indexing>
+ (?P<in>{_NAME_RE})\[(?P<idx>.+)\]$
+ )|(?P<attribute>
+ (?P<var>{_NAME_RE})(?:(?P<nullish>\?)?\.(?P<member>[^(]+)|\[(?P<member2>[^\]]+)\])\s*
+ )|(?P<function>
+ (?P<fname>{_NAME_RE})\((?P<args>.*)\)$
+ )''', expr)
+ if m and m.group('assign'):
+ left_val = local_vars.get(m.group('out'))
+
+ if not m.group('index'):
+ local_vars[m.group('out')] = self._operator(
+ m.group('op'), left_val, m.group('expr'), expr, local_vars, allow_recursion)
+ 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)
+
+ idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion)
+ if not isinstance(idx, (int, float)):
+ raise self.Exception(f'List index {idx} must be integer', expr)
+ idx = int(idx)
+ left_val[idx] = self._operator(
+ m.group('op'), self._index(left_val, idx), m.group('expr'), expr, local_vars, allow_recursion)
+ return left_val[idx], should_return
+
+ elif expr.isdigit():
+ return int(expr), should_return
+
+ elif expr == 'break':
+ raise JS_Break
elif expr == 'continue':
- raise JS_Continue()
+ raise JS_Continue
+ elif expr == 'undefined':
+ return JS_Undefined, should_return
+ elif expr == 'NaN':
+ return float('NaN'), should_return
- var_m = re.match(
- r'(?!if|return|true|false|null)(?P<name>%s)$' % _NAME_RE,
- expr)
- if var_m:
- return local_vars[var_m.group('name')]
+ elif m and m.group('return'):
+ return local_vars.get(m.group('name'), JS_Undefined), should_return
- try:
- return json.loads(expr)
- except ValueError:
- pass
+ with contextlib.suppress(ValueError):
+ return json.loads(js_to_json(expr, strict=True)), should_return
- m = re.match(
- r'(?P<in>%s)\[(?P<idx>.+)\]$' % _NAME_RE, expr)
- if m:
+ if m and m.group('indexing'):
val = local_vars[m.group('in')]
idx = self.interpret_expression(m.group('idx'), local_vars, allow_recursion)
- return val[idx]
+ return self._index(val, idx), should_return
- for op, opfunc in _OPERATORS:
- seperated = list(self._seperate(expr, op))
- if len(seperated) < 2:
+ for op in _OPERATORS:
+ separated = list(self._separate(expr, op))
+ right_expr = separated.pop()
+ while True:
+ if op in '?<>*-' and len(separated) > 1 and not separated[-1].strip():
+ separated.pop()
+ elif not (separated and op == '?' and right_expr.startswith('.')):
+ break
+ right_expr = f'{op}{right_expr}'
+ if op != '-':
+ right_expr = f'{separated.pop()}{op}{right_expr}'
+ if not separated:
continue
- right_val = seperated.pop()
- left_val = op.join(seperated)
- left_val, should_abort = self.interpret_statement(
- left_val, local_vars, allow_recursion - 1)
- if should_abort:
- raise ExtractorError(f'Premature left-side return of {op} in {expr!r}')
- right_val, should_abort = self.interpret_statement(
- right_val, local_vars, allow_recursion - 1)
- if should_abort:
- raise ExtractorError(f'Premature right-side return of {op} in {expr!r}')
- return opfunc(left_val or 0, right_val)
+ left_val = self.interpret_expression(op.join(separated), local_vars, allow_recursion)
+ return self._operator(op, left_val, right_expr, expr, local_vars, allow_recursion), should_return
- m = re.match(
- r'(?P<var>%s)(?:\.(?P<member>[^(]+)|\[(?P<member2>[^]]+)\])\s*' % _NAME_RE,
- expr)
- if m:
- variable = m.group('var')
- member = remove_quotes(m.group('member') or m.group('member2'))
+ if m and m.group('attribute'):
+ variable, member, nullish = m.group('var', 'member', 'nullish')
+ if not member:
+ member = self.interpret_expression(m.group('member2'), local_vars, allow_recursion)
arg_str = expr[m.end():]
if arg_str.startswith('('):
- arg_str, remaining = self._seperate_at_paren(arg_str, ')')
+ arg_str, remaining = self._separate_at_paren(arg_str)
else:
arg_str, remaining = None, arg_str
def assertion(cndn, msg):
""" assert, but without risk of getting optimized out """
if not cndn:
- raise ExtractorError(f'{member} {msg}: {expr}')
+ raise self.Exception(f'{member} {msg}', expr)
def eval_method():
- nonlocal member
- if variable == 'String':
- obj = str
- elif variable in local_vars:
- obj = local_vars[variable]
- else:
+ if (variable, member) == ('console', 'debug'):
+ if Debugger.ENABLED:
+ Debugger.write(self.interpret_expression(f'[{arg_str}]', local_vars, allow_recursion))
+ return
+
+ types = {
+ 'String': str,
+ 'Math': float,
+ }
+ obj = local_vars.get(variable, types.get(variable, NO_DEFAULT))
+ if obj is NO_DEFAULT:
if variable not in self._objects:
- self._objects[variable] = self.extract_object(variable)
- obj = self._objects[variable]
+ try:
+ self._objects[variable] = self.extract_object(variable)
+ except self.Exception:
+ if not nullish:
+ raise
+ obj = self._objects.get(variable, JS_Undefined)
+ if nullish and obj is JS_Undefined:
+ return JS_Undefined
+
+ # Member access
if arg_str is None:
- # Member access
- if member == 'length':
- return len(obj)
- return obj[member]
+ return self._index(obj, member, nullish)
# Function call
argvals = [
self.interpret_expression(v, local_vars, allow_recursion)
- for v in self._seperate(arg_str)]
+ for v in self._separate(arg_str)]
- if obj == str:
+ if obj is str:
if member == 'fromCharCode':
assertion(argvals, 'takes one or more arguments')
return ''.join(map(chr, argvals))
- raise ExtractorError(f'Unsupported string method {member}')
+ raise self.Exception(f'Unsupported String method {member}', expr)
+ elif obj is float:
+ if member == 'pow':
+ assertion(len(argvals) == 2, 'takes two arguments')
+ return argvals[0] ** argvals[1]
+ raise self.Exception(f'Unsupported Math method {member}', expr)
if member == 'split':
assertion(argvals, 'takes one or more arguments')
- assertion(argvals == [''], 'with arguments is not implemented')
- return list(obj)
+ assertion(len(argvals) == 1, 'with limit argument is not implemented')
+ return obj.split(argvals[0]) if argvals[0] else list(obj)
elif member == 'join':
assertion(isinstance(obj, list), 'must be applied on a list')
assertion(len(argvals) == 1, 'takes exactly one argument')
elif member == 'splice':
assertion(isinstance(obj, list), 'must be applied on a list')
assertion(argvals, 'takes one or more arguments')
- index, howMany = map(int, (argvals + [len(obj)])[:2])
+ index, how_many = map(int, ([*argvals, len(obj)])[:2])
if index < 0:
index += len(obj)
add_items = argvals[2:]
res = []
- for i in range(index, min(index + howMany, len(obj))):
+ for _ in range(index, min(index + how_many, len(obj))):
res.append(obj.pop(index))
for i, item in enumerate(add_items):
obj.insert(index + i, item)
elif member == 'forEach':
assertion(argvals, 'takes one or more arguments')
assertion(len(argvals) <= 2, 'takes at-most 2 arguments')
- f, this = (argvals + [''])[:2]
- return [f((item, idx, obj), this=this) for idx, item in enumerate(obj)]
+ f, this = ([*argvals, ''])[:2]
+ return [f((item, idx, obj), {'this': this}, allow_recursion) for idx, item in enumerate(obj)]
elif member == 'indexOf':
assertion(argvals, 'takes one or more arguments')
assertion(len(argvals) <= 2, 'takes at-most 2 arguments')
- idx, start = (argvals + [0])[:2]
+ idx, start = ([*argvals, 0])[:2]
try:
return obj.index(idx, start)
except ValueError:
return -1
+ elif member == 'charCodeAt':
+ assertion(isinstance(obj, str), 'must be applied on a string')
+ assertion(len(argvals) == 1, 'takes exactly one argument')
+ idx = argvals[0] if isinstance(argvals[0], int) else 0
+ if idx >= len(obj):
+ return None
+ return ord(obj[idx])
- if isinstance(obj, list):
- member = int(member)
- return obj[member](argvals)
+ idx = int(member) if isinstance(obj, list) else member
+ return obj[idx](argvals, allow_recursion=allow_recursion)
if remaining:
- return self.interpret_expression(
+ ret, should_abort = self.interpret_statement(
self._named_object(local_vars, eval_method()) + remaining,
local_vars, allow_recursion)
+ return ret, should_return or should_abort
else:
- return eval_method()
+ return eval_method(), should_return
- m = re.match(r'^(?P<func>%s)\((?P<args>[a-zA-Z0-9_$,]*)\)$' % _NAME_RE, expr)
- if m:
- fname = m.group('func')
- argvals = tuple([
- int(v) if v.isdigit() else local_vars[v]
- for v in self._seperate(m.group('args'))])
+ elif m and m.group('function'):
+ fname = m.group('fname')
+ argvals = [self.interpret_expression(v, local_vars, allow_recursion)
+ for v in self._separate(m.group('args'))]
if fname in local_vars:
- return local_vars[fname](argvals)
+ return local_vars[fname](argvals, allow_recursion=allow_recursion), should_return
elif fname not in self._functions:
self._functions[fname] = self.extract_function(fname)
- return self._functions[fname](argvals)
+ return self._functions[fname](argvals, allow_recursion=allow_recursion), should_return
- if expr:
- raise ExtractorError('Unsupported JS expression %r' % expr)
+ raise self.Exception(
+ f'Unsupported JS expression {truncate_string(expr, 20, 20) if expr != stmt else ""}', stmt)
+
+ def interpret_expression(self, expr, local_vars, allow_recursion):
+ ret, should_return = self.interpret_statement(expr, local_vars, allow_recursion)
+ if should_return:
+ raise self.Exception('Cannot return from an expression', expr)
+ return ret
def extract_object(self, objname):
_FUNC_NAME_RE = r'''(?:[a-zA-Z$0-9]+|"[a-zA-Z$0-9]+"|'[a-zA-Z$0-9]+')'''
obj = {}
obj_m = re.search(
r'''(?x)
- (?<!this\.)%s\s*=\s*{\s*
+ (?<!\.)%s\s*=\s*{\s*
(?P<fields>(%s\s*:\s*function\s*\(.*?\)\s*{.*?}(?:,\s*)?)*)
}\s*;
''' % (re.escape(objname), _FUNC_NAME_RE),
self.code)
+ if not obj_m:
+ raise self.Exception(f'Could not find object {objname}')
fields = obj_m.group('fields')
# Currently, it only supports function definitions
fields_m = re.finditer(
r'''(?x)
- (?P<key>%s)\s*:\s*function\s*\((?P<args>[a-z,]+)\){(?P<code>[^}]+)}
- ''' % _FUNC_NAME_RE,
+ (?P<key>%s)\s*:\s*function\s*\((?P<args>(?:%s|,)*)\){(?P<code>[^}]+)}
+ ''' % (_FUNC_NAME_RE, _NAME_RE),
fields)
for f in fields_m:
argnames = f.group('args').split(',')
- obj[remove_quotes(f.group('key'))] = self.build_function(argnames, f.group('code'))
+ name = remove_quotes(f.group('key'))
+ obj[name] = function_with_repr(self.build_function(argnames, f.group('code')), f'F<{name}>')
return obj
def extract_function_code(self, funcname):
""" @returns argnames, code """
func_m = re.search(
- r'''(?x)
- (?:function\s+%s|[{;,]\s*%s\s*=\s*function|var\s+%s\s*=\s*function)\s*
+ r'''(?xs)
+ (?:
+ function\s+%(name)s|
+ [{;,]\s*%(name)s\s*=\s*function|
+ (?:var|const|let)\s+%(name)s\s*=\s*function
+ )\s*
\((?P<args>[^)]*)\)\s*
- (?P<code>\{(?:(?!};)[^"]|"([^"]|\\")*")+\})''' % (
- re.escape(funcname), re.escape(funcname), re.escape(funcname)),
+ (?P<code>{.+})''' % {'name': re.escape(funcname)},
self.code)
- code, _ = self._seperate_at_paren(func_m.group('code'), '}') # refine the match
if func_m is None:
- raise ExtractorError('Could not find JS function %r' % funcname)
- return func_m.group('args').split(','), code
+ raise self.Exception(f'Could not find JS function "{funcname}"')
+ code, _ = self._separate_at_paren(func_m.group('code'))
+ return [x.strip() for x in func_m.group('args').split(',')], code
def extract_function(self, funcname):
- return self.extract_function_from_code(*self.extract_function_code(funcname))
+ return function_with_repr(
+ self.extract_function_from_code(*self.extract_function_code(funcname)),
+ f'F<{funcname}>')
def extract_function_from_code(self, argnames, code, *global_stack):
local_vars = {}
if mobj is None:
break
start, body_start = mobj.span()
- body, remaining = self._seperate_at_paren(code[body_start - 1:], '}')
- name = self._named_object(
- local_vars,
- self.extract_function_from_code(
- [str.strip(x) for x in mobj.group('args').split(',')],
- body, local_vars, *global_stack))
+ body, remaining = self._separate_at_paren(code[body_start - 1:])
+ name = self._named_object(local_vars, self.extract_function_from_code(
+ [x.strip() for x in mobj.group('args').split(',')],
+ body, local_vars, *global_stack))
code = code[:start] + name + remaining
return self.build_function(argnames, code, local_vars, *global_stack)
def build_function(self, argnames, code, *global_stack):
global_stack = list(global_stack) or [{}]
- local_vars = global_stack.pop(0)
-
- def resf(args, **kwargs):
- local_vars.update({
- **dict(zip(argnames, args)),
- **kwargs
- })
- var_stack = LocalNameSpace(local_vars, *global_stack)
- for stmt in self._seperate(code.replace('\n', ''), ';'):
- ret, should_abort = self.interpret_statement(stmt, var_stack)
- if should_abort:
- break
- return ret
+ argnames = tuple(argnames)
+
+ def resf(args, kwargs={}, allow_recursion=100):
+ global_stack[0].update(itertools.zip_longest(argnames, args, fillvalue=None))
+ global_stack[0].update(kwargs)
+ var_stack = LocalNameSpace(*global_stack)
+ ret, should_abort = self.interpret_statement(code.replace('\n', ' '), var_stack, allow_recursion - 1)
+ if should_abort:
+ return ret
return resf
projects / yt-dlp.git / blobdiff