story-research-zapwall/lib/retry.ts

/**
 * Retry utility with exponential backoff
 */

export interface RetryOptions {
  maxRetries?: number
  initialDelay?: number
  maxDelay?: number
  backoffMultiplier?: number
  retryable?: (error: Error) => boolean
}

const DEFAULT_OPTIONS: Required<RetryOptions> = {
  maxRetries: 3,
  initialDelay: 1000,
  maxDelay: 10000,
  backoffMultiplier: 2,
  retryable: () => true,
}

/**
 * Retry a function with exponential backoff
 */
export function retryWithBackoff<T>(fn: () => Promise<T>, options: RetryOptions = {}): Promise<T> {
  const opts = { ...DEFAULT_OPTIONS, ...options }

  const attempt = (current: number): Promise<T> => {
    return fn().catch((error) => {
      const normalizedError = error instanceof Error ? error : new Error(String(error))

      if (!opts.retryable(normalizedError) || current === opts.maxRetries) {
        throw normalizedError
      }

      const delay = Math.min(opts.initialDelay * Math.pow(opts.backoffMultiplier, current), opts.maxDelay)

      return new Promise((resolve) => {
        setTimeout(() => {
          resolve(attempt(current + 1))
        }, delay)
      })
    })
  }

  return attempt(0).catch((error) => {
    throw error ?? new Error('Retry failed')
  })
}

/**
 * Check if an error is a network error that should be retried
 */
export function isRetryableNetworkError(error: Error): boolean {
  // Network errors
  if (error.message.includes('network') || error.message.includes('fetch')) {
    return true
  }

  // Timeout errors
  if (error.message.includes('timeout') || error.message.includes('timed out')) {
    return true
  }

  // Connection errors
  if (error.message.includes('ECONNRESET') || error.message.includes('ECONNREFUSED')) {
    return true
  }

  // Rate limiting (429)
  if (error.message.includes('429') || error.message.includes('rate limit')) {
    return true
  }

  // Server errors (5xx)
  if (error.message.includes('50')) {
    return true
  }

  return false
}