Callback invoked on each retry. Receives the error thrown by `input` as the first argument with properties `attemptNumber` and `retriesLeft` which indicate the current attempt number and the number of attempts left, respectively.
The `onFailedAttempt` function can return a promise. For example, to add a [delay](https://github.com/sindresorhus/delay):
```
import pRetry = require('p-retry');
import delay = require('delay');
const run = async () => { ... };
(async () => {
const result = await pRetry(run, {
onFailedAttempt: async error => {
console.log('Waiting for 1 second before retrying');
await delay(1000);
}
});
})();
```
If the `onFailedAttempt` function throws, all retries will be aborted and the original promise will reject with the thrown error.
Returns a `Promise` that is fulfilled when calling `input` returns a fulfilled promise. If calling `input` returns a rejected promise, `input` is called again until the max retries are reached, it then rejects with the last rejection reason.
Does not retry on most `TypeErrors`, with the exception of network errors. This is done on a best case basis as different browsers have different [messages](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#Checking_that_the_fetch_was_successful) to indicate this.
See [whatwg/fetch#526 (comment)](https://github.com/whatwg/fetch/issues/526#issuecomment-554604080)
@param input - Receives the number of attempts as the first argument and is expected to return a `Promise` or any value.
@param options - Options are passed to the [`retry`](https://github.com/tim-kos/node-retry#retryoperationoptions) module.