receiver" for some reason. desc = Object.getOwnPropertyDescriptor(receiver, property); if (desc) { if (!desc.writable) { // Setter, getter, and non-writable fall into this. return false; } desc.value = value; Object.defineProperty(receiver, property, desc); } else { // Avoid setters that may be defined on Sub's prototype, but not on // the instance. defineProperty(receiver, property, value); } return true; }; } return set(target, property, value, receiver); } export default 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; }