@statesync/core

---

@statesync/core / withRetry

Function: withRetry()

function withRetry<T>(
   provider, 
   policy?, 
onRetry?): SnapshotProvider<T>;

Defined in: retry.ts:125

Wraps a SnapshotProvider with automatic retries using exponential backoff.

On each failed attempt (except the last), the onRetry callback is invoked before the delay. This can be used for logging, metrics, or to inspect the error. After all attempts are exhausted, the last error is re-thrown.

The returned provider has the same interface as the original, so it can be used as a drop-in replacement anywhere a SnapshotProvider is expected.

Type Parameters

Type Parameter	Description
T	The snapshot data type carried inside the SnapshotEnvelope.

Parameters

Parameter	Type	Description
provider	SnapshotProvider<T>	The original snapshot provider to wrap with retry logic.
policy?	RetryPolicy	Optional retry configuration. Uses RetryPolicy defaults when omitted.
onRetry?	(info) => void	Optional callback invoked after each failed attempt (before the backoff delay). Receives an object with: - attempt: The retry attempt number (1-based; 1 = first retry after initial failure). - error: The error thrown by the provider. - nextDelayMs: The delay in ms before the next attempt.

Returns

SnapshotProvider<T>

A new SnapshotProvider that retries on failure according to the given policy.

Throws

The last error from the provider if all attempts are exhausted.

Example

import { withRetry } from '@statesync/core';

const resilientProvider = withRetry(
  originalProvider,
  { maxAttempts: 5, initialDelayMs: 1000 },
  ({ attempt, error, nextDelayMs }) => {
    console.warn(`Retry ${attempt}, next delay: ${nextDelayMs}ms`, error);
  },
);