💻

• Would you like to work on a fix?

How are you using Babel?

Programmatic API (babel.transform, babel.parse)

Input code

let set;
class C {
  foo() {
    super.bar = 1;
  }
}

REPL

const set = {
  foo() {
    super.bar = 1;
  }
};

REPL

Configuration file name

No response

Configuration

n/a. Noticed this on REPL. Please see REPL links above.

Current and expected behavior

@babel/plugin-transform-classes and @babel/plugin-transform-object-super both create 2 helper functions called set and _set.

When a variable called set is present at top level in the source, the set helper is renamed to _set but the 2nd helper _set is not renamed, so it ends up as:

function _set(target, property, value, receiver, isStrict) {
  var s = _set(target, property, value, receiver || target);
  if (!s && isStrict) { throw new TypeError("failed to set property"); }
  return value;
}

This helper calls itself recursively, resulting in a stack overflow.

Environment

REPL (see links above).

Possible solution

set helper should be renamed in output to _set and _set renamed to _set2.

Or just change the name of the _set helper to something else e.g. _setWithStrictModeCheck, so the clash is not possible.

This same bug may also manifest in other plugins if they also use a pair of helpers called xxx and _xxx. I don't know if that's the case or not.

Additional context

No response