Warn on non-plain objects with same prototype and own fields

Right now there is a false negative with non-plain objects passed as props, e.g. errors:

const DisplayError = memo(({error}) => (
  <>
    <h1>{error.message}</h1>
    <p>{error.stack}<p>
    {error instanceof SomeSpecificError && <SomethingElse />}
  </>
)

const App = () => {
  const [counter, increment] = useReducer(state => state + 1, 0)
  useEffect(() => setTimeout(increment, 100), [])
  return <DisplayError error={new Error('message')} />
}

here, error prop is deep equal to the previous value but there’s no warning

One possible solution is to check both Object.getPrototypeOf(obj) and Object.keys(obj) for non-plain objects

[vzaidman]

Great! I’ll go over the pr asap! Thank you!

[barakyosi]

@vzaidman @VariableVasasMT I saw this issue was stale for few months so I opened a PR for it, hope you don’t mind. LMKWYT 😃