import { isObject } from '../error/utils';

class UnknownCauseError extends Error {
  [key: string]: unknown;
}
export function getCauseFromUnknown(cause: unknown): Error | undefined {
  if (cause instanceof Error) {
    return cause;
  }

  const type = typeof cause;
  if (type === 'undefined' || type === 'function' || cause === null) {
    return undefined;
  }

  // Primitive types just get wrapped in an error
  if (type !== 'object') {
    return new Error(String(cause));
  }

  // If it's an object, we'll create a synthetic error
  if (isObject(cause)) {
    const err = new UnknownCauseError();
    for (const key in cause) {
      err[key] = cause[key];
    }
    return err;
  }

  return undefined;
}