[jsinterp] Support multiple indexing (eg a[1][2])

* extend single indexing with improved RE (should probably use/have used _separate_at_paren())
* fix some cases that should have given undefined, not throwing
* standardise RE group names
* support length of objects, like {1: 2, 3: 4, length: 42}
master
dirkf 2 weeks ago
parent c1a03b1ac3
commit 81e64cacf2

@ -366,6 +366,16 @@ class TestJSInterpreter(unittest.TestCase):
self._test('function f() { let a; return a?.qq; }', JS_Undefined)
self._test('function f() { let a = {m1: 42, m2: 0 }; return a?.qq; }', JS_Undefined)
def test_indexing(self):
self._test('function f() { return [1, 2, 3, 4][3]}', 4)
self._test('function f() { return [1, [2, [3, [4]]]][1][1][1][0]}', 4)
self._test('function f() { var o = {1: 2, 3: 4}; return o[3]}', 4)
self._test('function f() { var o = {1: 2, 3: 4}; return o["3"]}', 4)
self._test('function f() { return [1, [2, {3: [4]}]][1][1]["3"][0]}', 4)
self._test('function f() { return [1, 2, 3, 4].length}', 4)
self._test('function f() { var o = {1: 2, 3: 4}; return o.length}', JS_Undefined)
self._test('function f() { var o = {1: 2, 3: 4}; o["length"] = 42; return o.length}', 42)
def test_regex(self):
self._test('function f() { let a=/,,[/,913,/](,)}/; }', None)

@ -549,13 +549,14 @@ class JSInterpreter(object):
except Exception as e:
raise self.Exception('Failed to evaluate {left_val!r:.50} {op} {right_val!r:.50}'.format(**locals()), expr, cause=e)
def _index(self, obj, idx, allow_undefined=False):
if idx == 'length':
def _index(self, obj, idx, allow_undefined=True):
if idx == 'length' and isinstance(obj, list):
return len(obj)
try:
return obj[int(idx)] if isinstance(obj, list) else obj[idx]
except Exception as e:
return obj[int(idx)] if isinstance(obj, list) else obj[compat_str(idx)]
except (TypeError, KeyError, IndexError) as e:
if allow_undefined:
# when is not allowed?
return JS_Undefined
raise self.Exception('Cannot get index {idx!r:.100}'.format(**locals()), expr=repr(obj), cause=e)
@ -882,13 +883,13 @@ class JSInterpreter(object):
m = re.match(r'''(?x)
(?P<assign>
(?P<out>{_NAME_RE})(?:\[(?P<index>[^\]]+?)\])?\s*
(?P<out>{_NAME_RE})(?:\[(?P<out_idx>(?:.+?\]\s*\[)*.+?)\])?\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})\[(?P<idx>.+)\]$
(?P<in>{_NAME_RE})\[(?P<in_idx>(?:.+?\]\s*\[)*.+?)\]$
)|(?P<attribute>
(?P<var>{_NAME_RE})(?:(?P<nullish>\?)?\.(?P<member>[^(]+)|\[(?P<member2>[^\]]+)\])\s*
)|(?P<function>
@ -898,19 +899,23 @@ class JSInterpreter(object):
if md.get('assign'):
left_val = local_vars.get(m.group('out'))
if not m.group('index'):
if not m.group('out_idx'):
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('Cannot index undefined variable ' + m.group('out'), expr=expr)
idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion)
if not isinstance(idx, (int, float)):
raise self.Exception('List index %s must be integer' % (idx, ), expr=expr)
indexes = re.split(r'\]\s*\[', m.group('out_idx'))
for i, idx in enumerate(indexes, 1):
idx = self.interpret_expression(idx, local_vars, allow_recursion)
if i < len(indexes):
left_val = self._index(left_val, idx)
if isinstance(idx, float):
idx = int(idx)
left_val[idx] = self._operator(
m.group('op'), self._index(left_val, idx), m.group('expr'), expr, local_vars, allow_recursion)
m.group('op'), self._index(left_val, idx) if m.group('op') else None,
m.group('expr'), expr, local_vars, allow_recursion)
return left_val[idx], should_return
elif expr.isdigit():
@ -939,8 +944,10 @@ class JSInterpreter(object):
if md.get('indexing'):
val = local_vars[m.group('in')]
idx = self.interpret_expression(m.group('idx'), local_vars, allow_recursion)
return self._index(val, idx), should_return
for idx in re.split(r'\]\s*\[', m.group('in_idx')):
idx = self.interpret_expression(idx, local_vars, allow_recursion)
val = self._index(val, idx)
return val, should_return
op_result = self.handle_operators(expr, local_vars, allow_recursion)
if op_result:
@ -989,7 +996,7 @@ class JSInterpreter(object):
# Member access
if arg_str is None:
return self._index(obj, member, nullish)
return self._index(obj, member)
# Function call
argvals = [

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