Add callback option when it retries

[shabailiu]

It would be useful to have a callback function whenever axios retries, for example to update UI status.

[recz5]

I'm working on an existing code based that has axios-retry implemented and it is hard to debug. It is difficult to identify if it is retrying. A callback would be helpful.

[rubennorte]

I think you could use a different interceptor to detect retries. You just need to register it after axios-retry and check the retry count. We're trying to keep the API minimal, and this use case can be implemented without adding new options.

[bbugh]

If anyone else ends up here trying to answer this question, here's an implementation based on the suggestion to use interceptors. The example is in TypeScript but it will be the same in JS, just remove the types.

This gets the count of the tries and logs a warning:

interface AxiosRetryRequestConfig extends AxiosRequestConfig {
  'axios-retry'?: {
    retryCount: number,
    lastRequestTime: number
  }
}

axios.interceptors.request.use((config: AxiosRequestConfig) => {
  const retryRequestData = (<AxiosRetryRequestConfig>config)['axios-retry']

  if (retryRequestData) {
    const retryCount = retryRequestData.retryCount
    logger.warn(`[webhook] Webhook call retry #${retryCount}: ${config.url}`)
  }

  return config
})

My logger output:

2019-03-21 14:23:00 [info]:     [webhook] Sending webhook to http://localhost/webhooks/somewhere
2019-03-21 14:23:02 [warn]:     [webhook] Webhook call retry #1: http://localhost/webhooks/somewhere
2019-03-21 14:23:05 [warn]:     [webhook] Webhook call retry #2: http://localhost/webhooks/somewhere
2019-03-21 14:23:06 [info]:     [webhook] Response from webhook call: 200 OK