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Error Handling

This guide covers best practices for handling errors in your expo-iap implementation.

Overview​

Expo IAP provides comprehensive error handling through standardized error codes and messages. All errors are returned as structured objects with consistent properties across iOS and Android platforms.

Error Structure​

interface IapError {
  code: string;
  message: string;
  debugMessage?: string;
  underlyingError?: any;
}

Common Error Scenarios​

Network Errors​

Handle network connectivity issues gracefully:

import {useIap} from 'expo-iap';

const {purchaseProduct} = useIap();

try {
  await purchaseProduct('product_id');
} catch (error) {
  if (error.code === 'E_NETWORK_ERROR') {
    // Handle network issues
    showRetryDialog();
  }
}

User Cancellation​

Gracefully handle when users cancel purchases:

try {
  await purchaseProduct('product_id');
} catch (error) {
  if (error.code === 'E_USER_CANCELLED') {
    // User cancelled the purchase
    // Don't show error message, just continue
    return;
  }
}

Payment Issues​

Handle various payment-related errors:

try {
  await purchaseProduct('product_id');
} catch (error) {
  switch (error.code) {
    case 'E_PAYMENT_INVALID':
      showMessage(
        'Invalid payment method. Please check your payment settings.',
      );
      break;
    case 'E_PAYMENT_NOT_ALLOWED':
      showMessage('Payments are not allowed on this device.');
      break;
    case 'E_INSUFFICIENT_FUNDS':
      showMessage('Insufficient funds. Please add payment method.');
      break;
    default:
      showMessage('Purchase failed. Please try again.');
  }
}

Error Recovery Strategies​

Retry Logic​

Implement exponential backoff for transient errors:

const retryWithBackoff = async (fn: () => Promise<any>, maxRetries = 3) => {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn();
    } catch (error) {
      if (i === maxRetries - 1) throw error;

      // Only retry on network or temporary errors
      if (['E_NETWORK_ERROR', 'E_SERVICE_UNAVAILABLE'].includes(error.code)) {
        await new Promise((resolve) =>
          setTimeout(resolve, Math.pow(2, i) * 1000),
        );
      } else {
        throw error;
      }
    }
  }
};

Graceful Degradation​

Provide fallback experiences:

const handlePurchase = async (productId: string) => {
  try {
    await purchaseProduct(productId);
  } catch (error) {
    if (error.code === 'E_IAP_NOT_AVAILABLE') {
      // Redirect to web subscription
      redirectToWebPurchase(productId);
    } else {
      showErrorMessage(error.message);
    }
  }
};

Logging and Analytics​

Track errors for debugging and analytics:

const trackError = (error: IapError, context: string) => {
  console.error(`IAP Error in ${context}:`, error);

  // Send to analytics
  analytics.track('iap_error', {
    error_code: error.code,
    error_message: error.message,
    context,
    platform: Platform.OS,
  });
};

Best Practices​

1. Always Handle Errors​

Never leave IAP operations without error handling:

// ❌ Bad
purchaseProduct('product_id');

// ✅ Good
try {
  await purchaseProduct('product_id');
} catch (error) {
  handlePurchaseError(error);
}

2. Provide User-Friendly Messages​

Convert technical errors to user-friendly messages:

const getUserFriendlyMessage = (error: IapError): string => {
  switch (error.code) {
    case 'E_USER_CANCELLED':
      return null; // Don't show message
    case 'E_NETWORK_ERROR':
      return 'Please check your internet connection and try again.';
    case 'E_PAYMENT_INVALID':
      return 'There was an issue with your payment method.';
    default:
      return 'Something went wrong. Please try again later.';
  }
};

3. Handle Platform Differences​

Some errors may be platform-specific:

const handlePlatformSpecificError = (error: IapError) => {
  if (
    Platform.OS === 'ios' &&
    error.code === 'E_STOREFRONT_COUNTRY_NOT_SUPPORTED'
  ) {
    showMessage('This product is not available in your country.');
  } else if (Platform.OS === 'android' && error.code === 'E_DEVELOPER_ERROR') {
    // Log for debugging but don't show to user
    console.error('Google Play configuration error:', error);
  }
};

See Also​