react-native-iap/src/modules/ios.ts

React Native In App Purchase Module.

import {Linking, NativeModules} from 'react-native';
import type {ResponseBody as ReceiptValidationResponse} from '@jeremybarbet/apple-api-types';

import {getIosModule, isIosStorekit2} from '../internal';
const {RNIapIos} = NativeModules;
import type {
  ProductIOS,
  ProductPurchase,
  Purchase,
  Sku,
  SubscriptionIOS,
} from '../types';
import type {PaymentDiscount} from '../types/apple';

import type {NativeModuleProps} from './common';

type getItems = (skus: Sku[]) => Promise<ProductIOS[] | SubscriptionIOS[]>;

type getAvailableItems = (
  automaticallyFinishRestoredTransactions: boolean,
) => Promise<Purchase[]>;

export type BuyProduct = (
  sku: Sku,
  andDangerouslyFinishTransactionAutomaticallyIOS: boolean,
  applicationUsername: string | undefined,
  quantity: number,
  withOffer: Record<keyof PaymentDiscount, string> | undefined,
) => Promise<Purchase>;

type clearTransaction = () => Promise<void>;
type clearProducts = () => Promise<void>;
type promotedProduct = () => Promise<ProductIOS | null>;
type buyPromotedProduct = () => Promise<void>;
type requestReceipt = (refresh: boolean) => Promise<string | undefined | null>;

type finishTransaction = (transactionIdentifier: string) => Promise<boolean>;

type getPendingTransactions = () => Promise<ProductPurchase[]>;
type presentCodeRedemptionSheet = () => Promise<null>;

export interface IosModuleProps extends NativeModuleProps {
  getItems: getItems;
  getAvailableItems: getAvailableItems;
  buyProduct: BuyProduct;
  clearTransaction: clearTransaction;
  clearProducts: clearProducts;
  promotedProduct: promotedProduct;
  buyPromotedProduct: buyPromotedProduct;
  requestReceipt: requestReceipt;
  finishTransaction: finishTransaction;
  getPendingTransactions: getPendingTransactions;
  presentCodeRedemptionSheet: presentCodeRedemptionSheet;
  disable: () => Promise<null>;
}

/**
 * Get the current receipt base64 encoded in IOS.
 * @returns {Promise<ProductPurchase[]>}
 */
export const getPendingPurchasesIOS = async (): Promise<ProductPurchase[]> =>
  getIosModule().getPendingTransactions();

/**
 * Get the current receipt base64 encoded in IOS.
 * 
 * The sequence should be as follows: 
 * Call getReceiptIOS({forceRefresh: false}). That will return the cached receipt that is available on TestFlight and Production. 
 * In the case of Sandbox the receipt might not be cached, causing it to return nil. 
 * In that case you might want to let the user that they will to be prompted for credentials. 
 * If they accept, call it again with `getReceiptIOS({forceRefresh:true}) If it fails or the user declines, assume they haven't purchased any items. 
 * Reference: https://developer.apple.com/forums/thread/662350 
 * 
 * From: https://apphud.com/blog/app-store-receipt-validation#what-is-app-store-receipt
 > Q: Does a receipt always exist in the app?
 > A: If a user downloaded the app from the App Store – yes. However, in sandbox if your app was installed via Xcode or Testflight, then there won't be a receipt until you make a purchase or restore.
 * 
 ## Usage 
 ```tsx
import {getReceiptIOS} from 'react-native-iap';
try{
  let receipt = await getReceiptIOS({forceRefresh: false});
  if(!receipt){
    // Let user know that they might get prompted for credentials
    const shouldShowPrompt = // Display UI with details, Did user agree?. this only for Sandbox testing
    if(shouldShowPrompt){
      receipt = await getReceiptIOS({forceRefresh: true});
    }
  }
}catch(error:Error){
  // error while getting the receipt, it might indicate an invalid receipt of a connection error while trying to get it
}
// If !receipt assume user doesn't own the items
```
 * @param {forceRefresh?:boolean} Requests the receipt from Bundle.main.appStoreReceiptURL. 
Based on the note above, looks like forceRefresh only makes sense when testing an app not downloaded from the Appstore.
And only afer a direct user action.
 * @returns {Promise<string | undefined | null>} The receipt data
 */
export const getReceiptIOS = async ({
  forceRefresh,
}: {
  forceRefresh?: boolean;
}): Promise<string | undefined | null> => {
  if (!isIosStorekit2()) {
    return RNIapIos.requestReceipt(forceRefresh ?? false);
  } else {
    return Promise.reject('Only available on Sk1');
  }
};
/**
 * Launches a modal to register the redeem offer code in IOS.
 * @returns {Promise<null>}
 */
export const presentCodeRedemptionSheetIOS = async (): Promise<null> =>
  getIosModule().presentCodeRedemptionSheet();

/**
 * Should Add Store Payment (iOS only)
 *   Indicates the the App Store purchase should continue from the app instead of the App Store.
 * @returns {Promise<Product | null>} promoted product
 */
export const getPromotedProductIOS = (): Promise<ProductIOS | null> => {
  if (!isIosStorekit2()) {
    return RNIapIos.promotedProduct();
  } else {
    return Promise.reject('Only available on Sk1');
  }
};

/**
 * Buy the currently selected promoted product (iOS only)
 *   Initiates the payment process for a promoted product. Should only be called in response to the `iap-promoted-product` event.
 * @returns {Promise<void>}
 */
export const buyPromotedProductIOS = (): Promise<void> =>
  getIosModule().buyPromotedProduct();

const fetchJsonOrThrow = async (
  url: string,
  receiptBody: Record<string, unknown>,
): Promise<ReceiptValidationResponse | false> => {
  const response = await fetch(url, {
    method: 'POST',
    headers: {
      Accept: 'application/json',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(receiptBody),
  });

  if (!response.ok) {
    throw Object.assign(new Error(response.statusText), {
      statusCode: response.status,
    });
  }

  return response.json();
};

const TEST_RECEIPT = 21007;
const requestAgnosticReceiptValidationIos = async (
  receiptBody: Record<string, unknown>,
): Promise<ReceiptValidationResponse | false> => {
  const response = await fetchJsonOrThrow(
    'https://buy.itunes.apple.com/verifyReceipt',
    receiptBody,
  );

  // Best practice is to check for test receipt and check sandbox instead
  // https://developer.apple.com/documentation/appstorereceipts/verifyreceipt
  if (response && response.status === TEST_RECEIPT) {
    const testResponse = await fetchJsonOrThrow(
      'https://sandbox.itunes.apple.com/verifyReceipt',
      receiptBody,
    );

    return testResponse;
  }

  return response;
};

/**
 * Validate receipt for iOS.
 * @param {object} receiptBody the receipt body to send to apple server.
 * @param {boolean} isTest whether this is in test environment which is sandbox.
 * @returns {Promise<Apple.ReceiptValidationResponse | false>}
 */
export const validateReceiptIos = async ({
  receiptBody,
  isTest,
}: {
  receiptBody: Record<string, unknown>;
  isTest?: boolean;
}): Promise<ReceiptValidationResponse | false> => {
  if (isTest == null) {
    return await requestAgnosticReceiptValidationIos(receiptBody);
  }

  const url = isTest
    ? 'https://sandbox.itunes.apple.com/verifyReceipt'
    : 'https://buy.itunes.apple.com/verifyReceipt';

  const response = await fetchJsonOrThrow(url, receiptBody);

  return response;
};

/**
 * Clear Transaction (iOS only)
 *   Finish remaining transactions. Related to issue #257 and #801
 *     link : https://github.com/hyochan/react-native-iap/issues/257
 *            https://github.com/hyochan/react-native-iap/issues/801
 * @returns {Promise<void>}
 */
export const clearTransactionIOS = (): Promise<void> =>
  getIosModule().clearTransaction();

/**
 * Clear valid Products (iOS only)
 *   Remove all products which are validated by Apple server.
 * @returns {void}
 */
export const clearProductsIOS = (): Promise<void> =>
  getIosModule().clearProducts();

export const deepLinkToSubscriptionsIos = (): Promise<void> =>
  Linking.openURL('https://apps.apple.com/account/subscriptions');