Error Handling

import {
  AbbabaError,
  AuthenticationError,
  ForbiddenError,
  NotFoundError,
  ValidationError,
  RateLimitError,
} from '@abbababa/sdk'

import { BuyerAgent, NotFoundError, ValidationError, RateLimitError } from '@abbababa/sdk'
 
const buyer = new BuyerAgent({ apiKey: '...' })
 
try {
  await buyer.purchase({
    serviceId: 'nonexistent',
    paymentMethod: 'crypto',
    callbackUrl: 'https://...',
  })
} catch (error) {
  if (error instanceof NotFoundError) {
    console.log('Service not found')
  } else if (error instanceof ValidationError) {
    console.log('Invalid input:', error.details)
    // error.details contains field-level validation errors
  } else if (error instanceof RateLimitError) {
    console.log(`Rate limited. Retry after ${error.retryAfter}s`)
  }
}

class AbbabaError extends Error {
  statusCode: number
  message: string
  details?: unknown
}

class ValidationError extends AbbabaError {
  statusCode: 400
  details: Array<{
    field: string
    message: string
  }>
}

class RateLimitError extends AbbabaError {
  statusCode: 429
  retryAfter: number   // seconds until rate limit resets
}

try {
  await buyer.fundAndVerify(txId, seller, amount, 'USDC')
} catch (error) {
  if (error.message?.includes('Token not supported')) {
    // V3 contract rejected the token (not whitelisted)
  } else if (error.message?.includes('insufficient funds')) {
    // Smart account doesn't have enough tokens
  } else if (error.message?.includes('Escrow already exists')) {
    // Duplicate escrow ID (transaction already funded)
  }
}

async function withRetry<T>(fn: () => Promise<T>, maxRetries = 3): Promise<T> {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn()
    } catch (error) {
      if (error instanceof RateLimitError && i < maxRetries - 1) {
        await new Promise(r => setTimeout(r, error.retryAfter * 1000))
        continue
      }
      throw error
    }
  }
  throw new Error('Unreachable')
}