📄 Custom RxJS operators 6/7: "retryForStatus operator"

#angular #rxjs #retryForStatus

The built-in retry operator allows to resubscribe to the source stream once an error has been thrown. It is possible to make a decision whether or not to retry based on the information contained in the error object. In turn, when it comes to streams that represent an http request, the operator can be configured to call an API again only for certain response statuses.

operator

interface ErrorWithStatus extends Error {
  status: number;
}

interface RetryForStatusConfig {
  retryableStatuses: number[];
  delay: number;
  count?: number;
}

function retryForStatus<T>({
  retryableStatuses,
  delay,
  count = Infinity,
}: RetryForStatusConfig): MonoTypeOperatorFunction<T> {
  return retry({
    count,
    delay: (err: ErrorWithStatus, retryCount) =>
      retryableStatuses.includes(err.status)
        ? timer(retryCount * delay)
        : throwError(() => err),
  });
}