refactor: enhance payment request handling and improve formatting

- Updated payment request construction to omit undefined properties, ensuring cleaner requests.
- Refactored payment item building logic to improve clarity and maintainability.
- Standardized price formatting in Google Pay request builder.
- Improved test coverage for payment request sanitization and validation.
- Adjusted various components to ensure consistent handling of payment request properties.

Author: piotr-graczyk-dev

example/app/(tabs)/index.tsx

@@ -43,17 +43,17 @@ export default function TabOneScreen() {
     if (canMakePayments) {
       Alert.alert(
         `${paymentServiceName} Available`,
-        `${paymentServiceName} is ready to use!`
+        `${paymentServiceName} is ready to use!`,
       );
     } else if (canSetupCards) {
       Alert.alert(
         "Setup Required",
-        `Please set up ${paymentServiceName} in Settings`
+        `Please set up ${paymentServiceName} in Settings`,
       );
     } else {
       Alert.alert(
         "Not Available",
-        `${paymentServiceName} is not available on this device`
+        `${paymentServiceName} is not available on this device`,
       );
     }
   };
@@ -98,7 +98,7 @@ export default function TabOneScreen() {
               clearItems();
             },
           },
-        ]
+        ],
       );
     } else if (paymentResult?.error) {
       Alert.alert("Payment Failed", paymentResult.error, [{ text: "OK" }]);

package/android/src/main/java/com/margelo/nitro/pay/GooglePayRequestBuilder.kt

@@ -3,11 +3,13 @@ package com.margelo.nitro.pay
 import com.google.android.gms.wallet.WalletConstants
 import org.json.JSONArray
 import org.json.JSONObject
+import java.util.Locale
 
 /**
  * Builder for Google Pay API request objects
  */
 object GooglePayRequestBuilder {
+    private val googlePayPriceLocale = Locale.US
 
     /**
      * Creates an IsReadyToPay request
@@ -138,7 +140,7 @@ object GooglePayRequestBuilder {
 
         return JSONObject().apply {
             put("totalPriceStatus", PaymentConstants.TOTAL_PRICE_STATUS_FINAL)
-            put("totalPrice", String.format("%.2f", totalAmount))
+            put("totalPrice", formatPrice(totalAmount))
             put("totalPriceLabel", PaymentConstants.TOTAL_PRICE_LABEL_DEFAULT)
             put("currencyCode", request.currencyCode)
             put("countryCode", request.countryCode)
@@ -165,11 +167,15 @@ object GooglePayRequestBuilder {
                         else 
                             PaymentConstants.PENDING_TYPE
                     )
-                    put("price", String.format("%.2f", item.amount))
+                    put("price", formatPrice(item.amount))
                 })
             }
         }
     }
+
+    private fun formatPrice(amount: Double): String {
+        return String.format(googlePayPriceLocale, "%.2f", amount)
+    }
 
     /**
      * Creates allowed auth methods

package/ios/HybridPaymentHandler.swift

@@ -30,7 +30,7 @@ private struct PaymentRequestBuilder {
         paymentRequest.merchantIdentifier = merchantIdentifier
         paymentRequest.countryCode = request.countryCode
         paymentRequest.currencyCode = request.currencyCode
-        paymentRequest.paymentSummaryItems = buildPaymentItems(request.paymentItems)
+        paymentRequest.paymentSummaryItems = buildPaymentItems(for: request)
         paymentRequest.merchantCapabilities = buildMerchantCapabilities(request.merchantCapabilities)
         paymentRequest.supportedNetworks = buildSupportedNetworks(request.supportedNetworks)
 
@@ -67,15 +67,38 @@ private struct PaymentRequestBuilder {
         return nil
     }
 
-    private static func buildPaymentItems(_ items: [PaymentItem]) -> [PKPaymentSummaryItem] {
-        return items.map { item in
+    private static func buildPaymentItems(for request: PaymentRequest) -> [PKPaymentSummaryItem] {
+        let lineItems = request.paymentItems.map { item in
             let pkItem = PKPaymentSummaryItem(
                 label: item.label,
                 amount: NSDecimalNumber(decimal: Decimal(item.amount))
             )
             pkItem.type = item.type == .final ? .final : .pending
             return pkItem
         }
+
+        guard request.paymentItems.count > 1 else {
+            return lineItems
+        }
+
+        let totalAmount = request.paymentItems.reduce(Decimal.zero) { partialResult, item in
+            partialResult + Decimal(item.amount)
+        }
+        let totalLabel: String
+        if let merchantName = request.merchantName?
+            .trimmingCharacters(in: CharacterSet.whitespacesAndNewlines),
+           !merchantName.isEmpty {
+            totalLabel = merchantName
+        } else {
+            totalLabel = "Total"
+        }
+        let totalItem = PKPaymentSummaryItem(
+            label: totalLabel,
+            amount: NSDecimalNumber(decimal: totalAmount)
+        )
+        totalItem.type = .final
+
+        return lineItems + [totalItem]
     }
 
     private static func buildMerchantCapabilities(_ capabilities: [String]) -> PKMerchantCapability {

package/src/hooks/__tests__/usePaymentCheckout.integration.test.ts

@@ -105,6 +105,13 @@ describe('usePaymentCheckout integration', () => {
     ])
     expect(result.current.paymentRequest.countryCode).toBe('US')
     expect(result.current.paymentRequest.currencyCode).toBe('USD')
+    expect(result.current.paymentRequest).not.toHaveProperty(
+      'applePayMerchantIdentifier'
+    )
+    expect(result.current.paymentRequest).not.toHaveProperty('merchantName')
+    expect(result.current.paymentRequest).not.toHaveProperty(
+      'googlePayMerchantId'
+    )
   })
 
   it('rejects startPayment when cart is empty', async () => {

package/src/hooks/usePaymentCheckout.ts

@@ -11,7 +11,11 @@ import type {
   PayServiceStatus,
   GooglePayEnvironment,
 } from '../types'
-import { createPaymentItem, calculateTotal } from '../utils'
+import {
+  createPaymentItem,
+  calculateTotal,
+  sanitizePaymentRequest,
+} from '../utils'
 
 /**
  * Configuration for `usePaymentCheckout`.
@@ -207,20 +211,20 @@ export function usePaymentCheckout(
       googlePayGatewayMerchantId,
     } = config
 
-    return {
-      applePayMerchantIdentifier,
+    return sanitizePaymentRequest({
       countryCode,
-      merchantName,
       currencyCode,
       supportedNetworks,
       merchantCapabilities,
       paymentItems:
         items.length > 0 ? items : [createPaymentItem('Total', 0, 'final')],
+      applePayMerchantIdentifier,
+      merchantName,
       googlePayMerchantId,
       googlePayEnvironment,
       googlePayGateway,
       googlePayGatewayMerchantId,
-    }
+    })
   }, [config, items])
 
   // Cart operations

package/src/utils/__tests__/paymentHelpers.test.ts

@@ -7,6 +7,7 @@ import {
   formatNetworkName,
   isNetworkSupported,
   parseAmount,
+  sanitizePaymentRequest,
 } from '../paymentHelpers'
 
 describe('paymentHelpers', () => {
@@ -77,6 +78,37 @@ describe('paymentHelpers', () => {
     expect(request.googlePayMerchantId).toBe('google-pay-merchant-id')
   })
 
+  it('omits undefined optional fields from created payment requests', () => {
+    const request = createPaymentRequest({
+      amount: 10,
+      label: 'Order',
+      merchantName: undefined,
+      googlePayMerchantId: undefined,
+      googlePayGateway: 'stripe',
+    })
+
+    expect(request).not.toHaveProperty('merchantName')
+    expect(request).not.toHaveProperty('googlePayMerchantId')
+    expect(request.googlePayGateway).toBe('stripe')
+  })
+
+  it('sanitizes payment requests before native bridging', () => {
+    const request = sanitizePaymentRequest({
+      countryCode: 'PL',
+      currencyCode: 'PLN',
+      paymentItems: [{ label: 'Order', amount: 10, type: 'final' }],
+      supportedNetworks: ['visa'],
+      merchantCapabilities: ['3DS'],
+      merchantName: undefined,
+      googlePayGateway: 'przelewy24',
+      googlePayGatewayMerchantId: undefined,
+    } as any)
+
+    expect(request).not.toHaveProperty('merchantName')
+    expect(request).not.toHaveProperty('googlePayGatewayMerchantId')
+    expect(request.googlePayGateway).toBe('przelewy24')
+  })
+
   it('formats and parses amount values', () => {
     expect(formatAmount(29.9)).toBe('29.90')
     expect(parseAmount('29.90')).toBeCloseTo(29.9)

package/src/utils/paymentHelpers.ts

@@ -29,6 +29,31 @@ export const CommonNetworks = {
   DISCOVER: 'discover',
 } as const
 
+const DEFAULT_SUPPORTED_NETWORKS: PaymentRequest['supportedNetworks'] = [
+  CommonNetworks.VISA,
+  CommonNetworks.MASTERCARD,
+  CommonNetworks.AMEX,
+  CommonNetworks.DISCOVER,
+]
+
+const DEFAULT_MERCHANT_CAPABILITIES: PaymentRequest['merchantCapabilities'] = [
+  '3DS',
+]
+
+function omitUndefinedProperties<T extends object>(value: T): T {
+  return Object.fromEntries(
+    Object.entries(value as Record<string, unknown>).filter(
+      ([, entryValue]) => entryValue !== undefined
+    )
+  ) as T
+}
+
+export function sanitizePaymentRequest(
+  request: PaymentRequest
+): PaymentRequest {
+  return omitUndefinedProperties(request)
+}
+
 /**
  * Creates a payment item with the specified label, amount, and type.
  *
@@ -103,24 +128,19 @@ export function createPaymentRequest(
     label,
     countryCode = 'US',
     currencyCode = 'USD',
-    supportedNetworks = [
-      CommonNetworks.VISA,
-      CommonNetworks.MASTERCARD,
-      CommonNetworks.AMEX,
-      CommonNetworks.DISCOVER,
-    ],
-    merchantCapabilities = ['3DS'],
+    supportedNetworks = DEFAULT_SUPPORTED_NETWORKS,
+    merchantCapabilities = DEFAULT_MERCHANT_CAPABILITIES,
     ...rest
   } = options
 
-  return {
+  return sanitizePaymentRequest({
     countryCode,
     currencyCode,
     paymentItems: [createPaymentItem(label, amount, 'final')],
     supportedNetworks,
     merchantCapabilities,
     ...rest,
-  }
+  } as PaymentRequest)
 }
 
 /**