This lib aims to apply retry patterns for various needed situations. The definitions were inspired by the retry implementation of Shaka Player.
retryPromise - Implements retries for a callback function with exponential backoff, returning a resolved promise if successeded and a rejected promise if doesn't.
Configuration:
retryParameters: {
action: 'Callback to be executed', (*)
maxAttempts: 'The maximum number of attempts that should be retried'
baseDelay: 'The delay before the first retry, in milliseconds',
backOffFactor: 'The multiplier for successive retry delays'
retryableErrors: 'A array specifying which HTTP status should be at retry flow'
}
(*) Mandatory fields.
The retryPromise method apply a fuzz factor of 50% in either direction. So if the ideal delay is 1000ms, the actual delay will be randomly chosen between 500ms and 1500ms.
When resolved: A object with the resource and the retry history flow, like:
{
resource: 'Hey! I as successfull in the third attempt!'
retryHistory: {
attempt_1 : { error: 'Failed at first' },
attempt_2 : { error: 'Failed at second' },
attempt_3 : { resource: 'Hey! I as successfull in the third attempt!' }
}
}
When rejected: A object with the error and the retry history flow, like:
{
error: 'Failed at my last attempt, sorry :('
retryHistory: {
attempt_1 : { error: 'Failed at first' },
attempt_2 : { error: 'Failed at second' },
attempt_3 : { error: 'Failed at my last attempt, sorry :(' }
}
}
retryPromise:
import { retryPromise } from 'retry-utils'
const getSomething = () => {
return fetch(`http://httpbin.org/status/500`)
.then((response) => {
if (response.ok) return response
throw new Error(response.statusText)
})
}
let retryParameters: {
action: getSomething,
maxAttempts: 5,
baseDelay: 1000,
backOffFactor: 3,
retryableErrors: [500, 501, 502]
}
retryPromise(retryParameters)
.then(() => console.log('Retry success'))
.catch(() => console.log('Retry error'))