[jsinterp] Add `charcodeAt` and bitwise overflow (#4706)

Authored by: elyse0
This commit is contained in:
Elyse 2022-08-19 00:30:04 -05:00 committed by pukkandan
parent bfbecd1174
commit f26af78a8a
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2 changed files with 27 additions and 3 deletions

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@ -352,6 +352,22 @@ class TestJSInterpreter(unittest.TestCase):
''')
self.assertEqual(jsi.call_function('x').flags & re.I, re.I)
def test_char_code_at(self):
jsi = JSInterpreter('function x(i){return "test".charCodeAt(i)}')
self.assertEqual(jsi.call_function('x', 0), 116)
self.assertEqual(jsi.call_function('x', 1), 101)
self.assertEqual(jsi.call_function('x', 2), 115)
self.assertEqual(jsi.call_function('x', 3), 116)
self.assertEqual(jsi.call_function('x', 4), None)
self.assertEqual(jsi.call_function('x', 'not_a_number'), 116)
def test_bitwise_operators_overflow(self):
jsi = JSInterpreter('function x(){return -524999584 << 5}')
self.assertEqual(jsi.call_function('x'), 379882496)
jsi = JSInterpreter('function x(){return 1236566549 << 5}')
self.assertEqual(jsi.call_function('x'), 915423904)
if __name__ == '__main__':
unittest.main()

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@ -18,10 +18,11 @@ from .utils import (
def _js_bit_op(op):
def wrapped(a, b):
def zeroise(x):
return 0 if x in (None, JS_Undefined) else x
return op(zeroise(a), zeroise(b))
def wrapped(a, b):
return op(zeroise(a), zeroise(b)) & 0xffffffff
return wrapped
@ -692,6 +693,13 @@ class JSInterpreter:
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])
idx = int(member) if isinstance(obj, list) else member
return obj[idx](argvals, allow_recursion=allow_recursion)