class Foo { static test() { return babelHelpers.classStaticPrivateFieldSpecGet(Foo, Foo, _bar); } test() { return babelHelpers.classStaticPrivateFieldSpecGet(Foo, Foo, _bar); } } var _bar = { writable: true, value: "foo" }; expect("bar" in Foo).toBe(false); expect(Foo.test()).toBe("foo"); expect(Foo.test()).toBe("foo");