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fix(array): respect deletion of Array.prototype[Symbol.iterator] #462

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Merged
dowdiness merged 2 commits into from
Jun 25, 2026
Merged

fix(array): respect deletion of Array.prototype[Symbol.iterator] #462

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c6cacec
fix(array): respect deletion of Array.prototype[Symbol.iterator]
dowdiness Jun 25, 2026
c1b97c1
fix(array): continue symbol lookup through non-Object array prototype…
dowdiness Jun 25, 2026
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29 changes: 3 additions & 26 deletions interpreter/runtime/property.mbt
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Original file line number Diff line number Diff line change
Expand Up @@ -959,32 +959,9 @@ fn Interpreter::get_computed_property_impl(
}
}
}
_ => ()
}
// Handle Symbol.iterator default for arrays
let iterator_sym = well_known_symbols.iterator
if sym.id == iterator_sym.id {
let (override_getter, override_value) = get_array_iterator_override(
arr,
well_known_symbols~,
)
match override_getter {
Some(getter) => return self.call_value(getter, obj, [], loc)
None => ()
}
match override_value {
Some(v) => return v
None => ()
}
// Return default array iterator
return make_method_func(
name="[Symbol.iterator]",
length=0,
realm_state=Some(realm_state),
fn(_this_val, _args) {
realm_state.make_array_iterator_value(arr)
},
)
Null | Undefined => ()
proto_val =>
return self.get_computed_property(proto_val, Symbol(sym), loc)
}
return Undefined

@chatgpt-codex-connector chatgpt-codex-connector Bot Jun 25, 2026

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P2 Badge Continue symbol lookup through array prototype overrides

When an array's prototype override is another array or a Proxy, get_array_prototype returns Array(...)/Proxy(...), so this return Undefined is now reached because the preceding walk only handles Object(proto_data). After deleting the fallback, cases like Object.setPrototypeOf(a, []); a[Symbol.iterator] or Object.setPrototypeOf(a, new Proxy(Array.prototype, {})); for (const x of a) {} lose the inherited Array.prototype iterator and throw, even though OrdinaryGet should keep walking through those prototype objects; route this path through the existing symbol-prototype walker or handle non-Object prototypes before returning.

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}
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