Can also greet my dad

[GoldenStack]

Hello.
I don't know if this is expected behaviour, but I can also greet my dad:

console.log(hiMom("Dad")); // Hi, Dad!

Thanks.

It appears as though there is a test case to avoid this:

test("should not say hi to dad", () => {
  expect(hiMom()).not.toBe("Hi, dad!");
});

but I can just put "Dad" in hiMom instead.