/**
* Copyright 2025 Chris Bunting <cbuntingde@gmail.com>
*
* Retry Logic - Exponential backoff with jitter
*/
import { config } from './config.js';
import { logger } from './logger.js';
import { isOperationalError } from './errors.js';
export interface RetryOptions {
maxRetries?: number;
baseDelay?: number;
maxDelay?: number;
retryable?: (error: Error) => boolean;
}
/**
* Calculate delay with exponential backoff and jitter
*/
function calculateDelay(attempt: number, baseDelay: number, maxDelay: number): number {
const exponentialDelay = baseDelay * Math.pow(2, attempt);
const jitter = Math.random() * 0.3 * exponentialDelay; // 0-30% jitter
return Math.min(exponentialDelay + jitter, maxDelay);
}
/**
* Retry a function with exponential backoff
*/
export async function retry<T>(
fn: () => Promise<T>,
options: RetryOptions = {}
): Promise<T> {
const {
maxRetries = config.MAX_RETRIES,
baseDelay = config.RETRY_DELAY_BASE,
maxDelay = config.RETRY_DELAY_MAX,
retryable = (error: Error) => {
// Retry on network errors, timeouts, and rate limits
if (!isOperationalError(error)) {
return false; // Don't retry programming errors
}
const message = error.message.toLowerCase();
return message.includes('timeout') ||
message.includes('rate limit') ||
message.includes('network') ||
message.includes('econnreset') ||
message.includes('etimedout') ||
message.includes('503') ||
message.includes('429');
},
} = options;
let lastError: Error | undefined;
for (let attempt = 0; attempt <= maxRetries; attempt++) {
try {
return await fn();
} catch (error) {
lastError = error instanceof Error ? error : new Error(String(error));
// Don't retry if error is not retryable
if (!retryable(lastError)) {
throw lastError;
}
// Don't retry on last attempt
if (attempt >= maxRetries) {
break;
}
const delay = calculateDelay(attempt, baseDelay, maxDelay);
logger.warn(`Retry attempt ${attempt + 1}/${maxRetries} after ${delay}ms`, {
error: lastError.message,
attempt: attempt + 1,
delay,
});
await new Promise(resolve => setTimeout(resolve, delay));
}
}
throw lastError || new Error('Retry failed with unknown error');
}
