codegen: user method named like a String builtin (internals.trim(value, schema)) mis-lowered to String.prototype.<m> on non-string receivers — joi

[proggeramlug]

Context: corpus — blocks joi (node_modules/joi/lib/validator.js:359): internals.trim(value, schema) calls joi's own internals.trim (2 args), but perry statically lowers any .trim(...) to String.prototype.trim (0 args) regardless of receiver, then bails: perry-codegen: String.trim takes no args, got 2.

Root

The static String-method lowering fires for <recv>.trim(...) even when <recv> is a non-string object with its own trim method. The arity guard (String.trim takes no args, got N) then fails the compile. This generalizes to any user method that shares a name with a String (or other builtin) method.

Minimal repro

const internals = { trim(value: string, schema: any) { return value + ":" + schema; } };
console.log(internals.trim("a", "b"));

perry → Error: ... String.trim takes no args, got 2 (compile fails). Node → a:b.

Fix direction

Gate the static String-method lowering on a provably-string receiver (typed string / string literal). For object/any/unknown receivers — or when the arg count doesn't match the builtin's signature — route to normal dynamic method dispatch (the receiver's own member) instead of forcing String.prototype.<m> and erroring on arity. Likely in crates/perry-codegen/src/lower_string_method.rs (where the arity guard lives).

Impact

joi directly; broadly, any package with user methods named like String builtins (trim, split, replace, slice, …) on non-string receivers — a common collision.