"use strict"; var _obj; const Base = {}; let value = 2; const obj = _obj = { set test(v) { expect(this).toBe(obj); value = v; }, set() { return babelHelpers.set(babelHelpers.getPrototypeOf(_obj), "test", 3, this, true); } }; Object.setPrototypeOf(obj, Base); expect(obj.set()).toBe(3); expect(Base.test).toBeUndefined(); expect(value).toBe(3); expect(obj.test).toBeUndefined();