Function isError

packages/expect-utils/src/utils.ts:559–568

(value: unknown)

// Copied from https://github.com/graingert/angular.js/blob/a43574052e9775cbc1d7dd8a086752c979b0f020/src/Angular.js#L685-L693
export const isError = (value: unknown): value is Error => {
  switch (Object.prototype.toString.call(value)) {
    case '[object Error]':
    case '[object Exception]':
    case '[object DOMException]':
      return true;
    default:
      return value instanceof Error;
  }
};

export function emptyObject(obj: unknown): boolean {
  return obj && typeof obj === 'object' ? Object.keys(obj).length === 0 : false;