Unexpected warning for error boundaries without getDerivedStateFromError

(Note: I dismissed the idea described here by now, but I still felt like reporting my findings.)

Steps to reproduce

I create a reusable error boundary component, ErrorCatcher, in order to deduplicate across different error boundary components.

class ErrorCatcher extends React.Component {
  componentDidCatch(error, info) {
    this.props.onError(error);
  }

  render() {
    return this.props.children;
  }
}

I then create new error boundary on top of that. For example:

function ErrorBoundary({children}) {
  const [error, setError] = useState(null)

  if (error) {
    return <ErrorMessage error={error} />
  }

  return (
    <ErrorCatcher
      onError={error => setError(error)}}
    >
      {children}
    </ErrorCatcher>
  )
}

For convenience, check out this Codesandbox for a live example.

Actual Behavior

Testing it out, I notice that React prints the following warning to the console:

Warning: ErrorCatcher: Error boundaries should implement getDerivedStateFromError(). In that method, return a state update to display an error message or fallback UI.

Expected Behavior

Checking the documentation, I find the following (emphasis mine):

A class component becomes an error boundary if it defines either (or both) of the lifecycle methods [...]

That leaves me a bit puzzled, since on the one hand the documentation is offering me to define either, and on the other I get a warning. I want the documentation to be explicit about eventual error and warning messages.

If you see some value in enabling users to create ErrorCatcher, without being bugged by the warning, I could see other solutions: get rid of the message, or make it optional.

Kindest regards 🙃

Issue nêu tài liệu về error-boundary và một bản tái hiện trên Codesandbox, nhưng không có tệp repository hoặc test nào. Hãy bắt đầu bằng cách kiểm tra mối quan hệ được ghi chép giữa componentDidCatch, getDerivedStateFromError và cảnh báo phản đối bản tái hiện; hoàn tất khi tài liệu khớp một cách rõ ràng với hành vi quan sát được.