type ErrorWithMessageType = {
  message: string
}

function isErrorWithMessage(error: unknown): boolean {
  return (
    typeof error === 'object' &&
    error !== null &&
    'message' in error &&
    typeof (error as Record<string, unknown>)['message'] === 'string'
  )
}

function toErrorWithMessage(maybeError: unknown): ErrorWithMessageType {
  if (isErrorWithMessage(maybeError)) {
    return maybeError as ErrorWithMessageType
  }

  try {
    return new Error(JSON.stringify(maybeError))
  } catch {
    // Fallback in case there's an error stringifying the 
    // maybeError (for example, with circular references).
    return new Error(String(maybeError))
  }
}

export function getErrorMessage(error: unknown) {
  return toErrorWithMessage(error).message
}