mirror of
https://codeberg.org/polarisfm/youtube-dl
synced 2024-12-22 22:47:55 +01:00
[jsinterp] Beef up and add tests
In preparation for #4822, extend jsinterp by a lot. (We may even have to/want to write a proper interpreter with actual parsing)
This commit is contained in:
Philipp Hagemeister
parent
4a3da4ebdb
commit
9e3f19919a
95
test/test_jsinterp.py
Normal file
95
test/test_jsinterp.py
Normal file
@ -0,0 +1,95 @@
|
||||
#!/usr/bin/env python
|
||||
|
||||
from __future__ import unicode_literals
|
||||
|
||||
# Allow direct execution
|
||||
import os
|
||||
import sys
|
||||
import unittest
|
||||
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
|
||||
|
||||
from youtube_dl.jsinterp import JSInterpreter
|
||||
|
||||
|
||||
class TestJSInterpreter(unittest.TestCase):
|
||||
def test_basic(self):
|
||||
jsi = JSInterpreter('function x(){;}')
|
||||
self.assertEqual(jsi.call_function('x'), None)
|
||||
|
||||
jsi = JSInterpreter('function x3(){return 42;}')
|
||||
self.assertEqual(jsi.call_function('x3'), 42)
|
||||
|
||||
def test_calc(self):
|
||||
jsi = JSInterpreter('function x4(a){return 2*a+1;}')
|
||||
self.assertEqual(jsi.call_function('x4', 3), 7)
|
||||
|
||||
def test_empty_return(self):
|
||||
jsi = JSInterpreter('function f(){return; y()}')
|
||||
self.assertEqual(jsi.call_function('f'), None)
|
||||
|
||||
def test_morespace(self):
|
||||
jsi = JSInterpreter('function x (a) { return 2 * a + 1 ; }')
|
||||
self.assertEqual(jsi.call_function('x', 3), 7)
|
||||
|
||||
jsi = JSInterpreter('function f () { x = 2 ; return x; }')
|
||||
self.assertEqual(jsi.call_function('f'), 2)
|
||||
|
||||
def test_strange_chars(self):
|
||||
jsi = JSInterpreter('function $_xY1 ($_axY1) { var $_axY2 = $_axY1 + 1; return $_axY2; }')
|
||||
self.assertEqual(jsi.call_function('$_xY1', 20), 21)
|
||||
|
||||
def test_operators(self):
|
||||
jsi = JSInterpreter('function f(){return 1 << 5;}')
|
||||
self.assertEqual(jsi.call_function('f'), 32)
|
||||
|
||||
jsi = JSInterpreter('function f(){return 19 & 21;}')
|
||||
self.assertEqual(jsi.call_function('f'), 17)
|
||||
|
||||
jsi = JSInterpreter('function f(){return 11 >> 2;}')
|
||||
self.assertEqual(jsi.call_function('f'), 2)
|
||||
|
||||
def test_array_access(self):
|
||||
jsi = JSInterpreter('function f(){var x = [1,2,3]; x[0] = 4; x[0] = 5; x[2] = 7; return x;}')
|
||||
self.assertEqual(jsi.call_function('f'), [5, 2, 7])
|
||||
|
||||
def test_parens(self):
|
||||
jsi = JSInterpreter('function f(){return (1) + (2) * ((( (( (((((3)))))) )) ));}')
|
||||
self.assertEqual(jsi.call_function('f'), 7)
|
||||
|
||||
jsi = JSInterpreter('function f(){return (1 + 2) * 3;}')
|
||||
self.assertEqual(jsi.call_function('f'), 9)
|
||||
|
||||
def test_assignments(self):
|
||||
jsi = JSInterpreter('function f(){var x = 20; x = 30 + 1; return x;}')
|
||||
self.assertEqual(jsi.call_function('f'), 31)
|
||||
|
||||
jsi = JSInterpreter('function f(){var x = 20; x += 30 + 1; return x;}')
|
||||
self.assertEqual(jsi.call_function('f'), 51)
|
||||
|
||||
jsi = JSInterpreter('function f(){var x = 20; x -= 30 + 1; return x;}')
|
||||
self.assertEqual(jsi.call_function('f'), -11)
|
||||
|
||||
def test_comments(self):
|
||||
jsi = JSInterpreter('''
|
||||
function x() {
|
||||
var x = /* 1 + */ 2;
|
||||
var y = /* 30
|
||||
* 40 */ 50;
|
||||
return x + y;
|
||||
}
|
||||
''')
|
||||
self.assertEqual(jsi.call_function('x'), 52)
|
||||
|
||||
def test_precedence(self):
|
||||
jsi = JSInterpreter('''
|
||||
function x() {
|
||||
var a = [10, 20, 30, 40, 50];
|
||||
var b = 6;
|
||||
a[0]=a[b%a.length];
|
||||
return a;
|
||||
}''')
|
||||
self.assertEqual(jsi.call_function('x'), [20, 20, 30, 40, 50])
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
unittest.main()
|
||||
@ -1,59 +1,122 @@
|
||||
from __future__ import unicode_literals
|
||||
|
||||
import json
|
||||
import operator
|
||||
import re
|
||||
|
||||
from .utils import (
|
||||
ExtractorError,
|
||||
)
|
||||
|
||||
_OPERATORS = [
|
||||
('|', operator.or_),
|
||||
('^', operator.xor),
|
||||
('&', operator.and_),
|
||||
('>>', operator.rshift),
|
||||
('<<', operator.lshift),
|
||||
('-', operator.sub),
|
||||
('+', operator.add),
|
||||
('%', operator.mod),
|
||||
('/', operator.div),
|
||||
('*', 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]*'
|
||||
|
||||
|
||||
class JSInterpreter(object):
|
||||
def __init__(self, code):
|
||||
self.code = code
|
||||
def __init__(self, code, objects=None):
|
||||
if objects is None:
|
||||
objects = {}
|
||||
self.code = self._remove_comments(code)
|
||||
self._functions = {}
|
||||
self._objects = {}
|
||||
self._objects = objects
|
||||
|
||||
def interpret_statement(self, stmt, local_vars, allow_recursion=20):
|
||||
def _remove_comments(self, code):
|
||||
return re.sub(r'(?s)/\*.*?\*/', '', code)
|
||||
|
||||
def interpret_statement(self, stmt, local_vars, allow_recursion=100):
|
||||
if allow_recursion < 0:
|
||||
raise ExtractorError('Recursion limit reached')
|
||||
|
||||
if stmt.startswith('var '):
|
||||
stmt = stmt[len('var '):]
|
||||
ass_m = re.match(r'^(?P<out>[a-z]+)(?:\[(?P<index>[^\]]+)\])?' +
|
||||
r'=(?P<expr>.*)$', stmt)
|
||||
if ass_m:
|
||||
if ass_m.groupdict().get('index'):
|
||||
def assign(val):
|
||||
lvar = local_vars[ass_m.group('out')]
|
||||
idx = self.interpret_expression(
|
||||
ass_m.group('index'), local_vars, allow_recursion)
|
||||
assert isinstance(idx, int)
|
||||
lvar[idx] = val
|
||||
return val
|
||||
expr = ass_m.group('expr')
|
||||
else:
|
||||
def assign(val):
|
||||
local_vars[ass_m.group('out')] = val
|
||||
return val
|
||||
expr = ass_m.group('expr')
|
||||
elif stmt.startswith('return '):
|
||||
assign = lambda v: v
|
||||
expr = stmt[len('return '):]
|
||||
should_abort = False
|
||||
stmt = stmt.lstrip()
|
||||
stmt_m = re.match(r'var\s', stmt)
|
||||
if stmt_m:
|
||||
expr = stmt[len(stmt_m.group(0)):]
|
||||
else:
|
||||
# Try interpreting it as an expression
|
||||
expr = stmt
|
||||
assign = lambda v: v
|
||||
return_m = re.match(r'return(?:\s+|$)', stmt)
|
||||
if return_m:
|
||||
expr = stmt[len(return_m.group(0)):]
|
||||
should_abort = True
|
||||
else:
|
||||
# Try interpreting it as an expression
|
||||
expr = stmt
|
||||
|
||||
v = self.interpret_expression(expr, local_vars, allow_recursion)
|
||||
return assign(v)
|
||||
return v, should_abort
|
||||
|
||||
def interpret_expression(self, expr, local_vars, allow_recursion):
|
||||
expr = expr.strip()
|
||||
|
||||
if expr == '': # Empty expression
|
||||
return None
|
||||
|
||||
if expr.startswith('('):
|
||||
parens_count = 0
|
||||
for m in re.finditer(r'[()]', expr):
|
||||
if m.group(0) == '(':
|
||||
parens_count += 1
|
||||
else:
|
||||
parens_count -= 1
|
||||
if parens_count == 0:
|
||||
sub_expr = expr[1:m.start()]
|
||||
sub_result = self.interpret_expression(
|
||||
sub_expr, local_vars, allow_recursion)
|
||||
remaining_expr = expr[m.end():].strip()
|
||||
if not remaining_expr:
|
||||
return sub_result
|
||||
else:
|
||||
expr = json.dumps(sub_result) + remaining_expr
|
||||
break
|
||||
else:
|
||||
raise ExtractorError('Premature end of parens in %r' % expr)
|
||||
|
||||
for op, opfunc in _ASSIGN_OPERATORS:
|
||||
m = re.match(r'''(?x)
|
||||
(?P<out>%s)(?:\[(?P<index>[^\]]+?)\])?
|
||||
\s*%s
|
||||
(?P<expr>.*)$''' % (_NAME_RE, re.escape(op)), expr)
|
||||
if not m:
|
||||
continue
|
||||
right_val = self.interpret_expression(
|
||||
m.group('expr'), local_vars, allow_recursion - 1)
|
||||
|
||||
if m.groupdict().get('index'):
|
||||
lvar = local_vars[m.group('out')]
|
||||
idx = self.interpret_expression(
|
||||
m.group('index'), local_vars, allow_recursion)
|
||||
assert isinstance(idx, int)
|
||||
cur = lvar[idx]
|
||||
val = opfunc(cur, right_val)
|
||||
lvar[idx] = val
|
||||
return val
|
||||
else:
|
||||
cur = local_vars.get(m.group('out'))
|
||||
val = opfunc(cur, right_val)
|
||||
local_vars[m.group('out')] = val
|
||||
return val
|
||||
|
||||
if expr.isdigit():
|
||||
return int(expr)
|
||||
|
||||
if expr.isalpha():
|
||||
return local_vars[expr]
|
||||
var_m = re.match(
|
||||
r'(?!if|return|true|false)(?P<name>%s)$' % _NAME_RE,
|
||||
expr)
|
||||
if var_m:
|
||||
return local_vars[var_m.group('name')]
|
||||
|
||||
try:
|
||||
return json.loads(expr)
|
||||
@ -61,7 +124,7 @@ class JSInterpreter(object):
|
||||
pass
|
||||
|
||||
m = re.match(
|
||||
r'^(?P<var>[$a-zA-Z0-9_]+)\.(?P<member>[^(]+)(?:\(+(?P<args>[^()]*)\))?$',
|
||||
r'(?P<var>%s)\.(?P<member>[^(]+)(?:\(+(?P<args>[^()]*)\))?$' % _NAME_RE,
|
||||
expr)
|
||||
if m:
|
||||
variable = m.group('var')
|
||||
@ -114,23 +177,31 @@ class JSInterpreter(object):
|
||||
return obj[member](argvals)
|
||||
|
||||
m = re.match(
|
||||
r'^(?P<in>[a-z]+)\[(?P<idx>.+)\]$', expr)
|
||||
r'(?P<in>%s)\[(?P<idx>.+)\]$' % _NAME_RE, expr)
|
||||
if m:
|
||||
val = local_vars[m.group('in')]
|
||||
idx = self.interpret_expression(
|
||||
m.group('idx'), local_vars, allow_recursion - 1)
|
||||
return val[idx]
|
||||
|
||||
m = re.match(r'^(?P<a>.+?)(?P<op>[%])(?P<b>.+?)$', expr)
|
||||
if m:
|
||||
a = self.interpret_expression(
|
||||
m.group('a'), local_vars, allow_recursion)
|
||||
b = self.interpret_expression(
|
||||
m.group('b'), local_vars, allow_recursion)
|
||||
return a % b
|
||||
for op, opfunc in _OPERATORS:
|
||||
m = re.match(r'(?P<x>.+?)%s(?P<y>.+)' % re.escape(op), expr)
|
||||
if not m:
|
||||
continue
|
||||
x, abort = self.interpret_statement(
|
||||
m.group('x'), local_vars, allow_recursion - 1)
|
||||
if abort:
|
||||
raise ExtractorError(
|
||||
'Premature left-side return of %s in %r' % (op, expr))
|
||||
y, abort = self.interpret_statement(
|
||||
m.group('y'), local_vars, allow_recursion - 1)
|
||||
if abort:
|
||||
raise ExtractorError(
|
||||
'Premature right-side return of %s in %r' % (op, expr))
|
||||
return opfunc(x, y)
|
||||
|
||||
m = re.match(
|
||||
r'^(?P<func>[a-zA-Z$]+)\((?P<args>[a-z0-9,]+)\)$', expr)
|
||||
r'^(?P<func>%s)\((?P<args>[a-zA-Z0-9_$,]+)\)$' % _NAME_RE, expr)
|
||||
if m:
|
||||
fname = m.group('func')
|
||||
argvals = tuple([
|
||||
@ -139,6 +210,7 @@ class JSInterpreter(object):
|
||||
if fname not in self._functions:
|
||||
self._functions[fname] = self.extract_function(fname)
|
||||
return self._functions[fname](argvals)
|
||||
|
||||
raise ExtractorError('Unsupported JS expression %r' % expr)
|
||||
|
||||
def extract_object(self, objname):
|
||||
@ -162,9 +234,11 @@ class JSInterpreter(object):
|
||||
|
||||
def extract_function(self, funcname):
|
||||
func_m = re.search(
|
||||
(r'(?:function %s|[{;]%s\s*=\s*function)' % (
|
||||
re.escape(funcname), re.escape(funcname))) +
|
||||
r'\((?P<args>[a-z,]+)\){(?P<code>[^}]+)}',
|
||||
r'''(?x)
|
||||
(?:function\s+%s|[{;]%s\s*=\s*function)\s*
|
||||
\((?P<args>[^)]*)\)\s*
|
||||
\{(?P<code>[^}]+)\}''' % (
|
||||
re.escape(funcname), re.escape(funcname)),
|
||||
self.code)
|
||||
if func_m is None:
|
||||
raise ExtractorError('Could not find JS function %r' % funcname)
|
||||
@ -172,10 +246,16 @@ class JSInterpreter(object):
|
||||
|
||||
return self.build_function(argnames, func_m.group('code'))
|
||||
|
||||
def call_function(self, funcname, *args):
|
||||
f = self.extract_function(funcname)
|
||||
return f(args)
|
||||
|
||||
def build_function(self, argnames, code):
|
||||
def resf(args):
|
||||
local_vars = dict(zip(argnames, args))
|
||||
for stmt in code.split(';'):
|
||||
res = self.interpret_statement(stmt, local_vars)
|
||||
res, abort = self.interpret_statement(stmt, local_vars)
|
||||
if abort:
|
||||
break
|
||||
return res
|
||||
return resf
|
||||
|
||||
Loading…
Reference in New Issue
Block a user