Add subscription deferral for Google play

README.md

@@ -33,14 +33,28 @@ var payment = {
 
 ### Purchase verification ( all platforms )
 
-A single method is exposed to verify purchase receipts:
+A method is exposed to verify purchase receipts:
 
 ```javascript
 iap.verifyPayment(platform, payment, function (error, response) {
 	/* your code */
 });
 ```
 
+Or, if you prefer a promise-based alternative: 
+
+```javascript
+iap.verifyPayment(platform, payment)
+.then(
+    response => {	
+        /* your code */ 
+    },
+    error => {
+        /* your code */ 
+    }
+)
+```
+
 The receipt you pass must conform to the requirements of the backend you are verifying with. Read
 the next chapter for more information on the format.
 
@@ -57,6 +71,34 @@ iap.cancelSubscription("google", payment, function (error, response) {
 });
 ```
 
+Or, if you prefer a promise-based alternative: 
+
+```javascript
+iap.cancelSubscription(platform, payment)
+.then(
+    response => {    
+        /* your code */ 
+    },
+    error => {
+        /* your code */ 
+    }
+)
+```
+
+### Subscription deferral ( Google Play only )
+
+Google exposes [an API for deferral](https://developers.google.com/android-publisher/api-ref/purchases/subscriptions/defer) of recurring suscriptions. This might be used to extend a user's subscription purchase until a specified future expiration time ( useful to grant your users some free days or months ).
+
+```javascript
+var deferralInfo = {
+	expectedExpiryTimeMillis: 1546616722237,
+	desiredExpiryTimeMillis: 1547716722237,
+};
+iap.deferSubscription("google", payment, deferralInfo, function (error, response) {
+	/* your code */
+});
+```
+
 ## Supported platforms
 
 ### Amazon

index.js

@@ -7,8 +7,17 @@ const platforms = {
 	roku: require('./lib/roku')
 };
 
+const promisify = (fn) => {
+	return (...args) => {
+		return new Promise((resolve, reject) => {
+			fn(...args, (err, res) => {
+				return (err ? reject(err) : resolve(res));
+			});
+		});
+	};
+};
 
-exports.verifyPayment = function (platform, payment, cb) {
+function verifyPayment(platform, payment, cb) {
 	function syncError(error) {
 		process.nextTick(function () {
 			cb(error);
@@ -34,10 +43,9 @@ exports.verifyPayment = function (platform, payment, cb) {
 
 		cb(null, result);
 	});
-};
+}
 
-
-exports.cancelSubscription = function (platform, payment, cb) {
+function cancelSubscription(platform, payment, cb) {
 	function syncError(error) {
 		process.nextTick(function () {
 			cb(error);
@@ -64,6 +72,86 @@ exports.cancelSubscription = function (platform, payment, cb) {
 			return cb(error);
 		}
 
+		cb(null, result);
+	});
+}
+
+exports.verifyPayment = (platform, payment, cb) => {
+	return (cb ? verifyPayment(platform, payment, cb) : promisify(verifyPayment)(platform, payment));
+};
+
+exports.cancelSubscription = (platform, payment, cb) => {
+	return (cb ? cancelSubscription(platform, payment, cb) : promisify(cancelSubscription)(platform, payment));
+};
+
+
+exports.deferSubscription = function (platform, payment, deferralInfo, cb) {
+	function syncError(error) {
+		process.nextTick(function () {
+			cb(error);
+		});
+	}
+
+	if (!payment) {
+		return syncError(new Error('No payment given'));
+	}
+
+	if (!deferralInfo) {
+		return syncError(new Error('No deferralInfo given'));
+	}
+
+	const engine = platforms[platform];
+
+	if (!engine) {
+		return syncError(new Error(`Platform ${platform} not recognized`));
+	}
+
+	if (!engine.deferSubscription) {
+		return syncError(new Error(`Platform ${platform
+		} does not have deferSubscription method`));
+	}
+
+	engine.deferSubscription(payment, deferralInfo, function (error, result) {
+		if (error) {
+			return cb(error);
+		}
+
+		cb(null, result);
+	});
+};
+
+
+exports.deferSubscription = function (platform, payment, deferralInfo, cb) {
+	function syncError(error) {
+		process.nextTick(function () {
+			cb(error);
+		});
+	}
+
+	if (!payment) {
+		return syncError(new Error('No payment given'));
+	}
+
+	if (!deferralInfo) {
+		return syncError(new Error('No deferralInfo given'));
+	}
+
+	const engine = platforms[platform];
+
+	if (!engine) {
+		return syncError(new Error(`Platform ${platform} not recognized`));
+	}
+
+	if (!engine.deferSubscription) {
+		return syncError(new Error(`Platform ${platform
+		} does not have deferSubscription method`));
+	}
+
+	engine.deferSubscription(payment, deferralInfo, function (error, result) {
+		if (error) {
+			return cb(error);
+		}
+
 		cb(null, result);
 	});
 };

lib/apple/index.js

@@ -16,7 +16,9 @@ const responses = {
 	21005: 'The receipt server is not currently available.',
 	21006: 'This receipt is valid but the subscription has expired. When this status code is returned to your server, the receipt data is also decoded and returned as part of the response.',
 	21007: 'This receipt is from the test environment, but it was sent to the production service for verification. Send it to the test environment service instead.',
-	21008: 'This receipt is from the production receipt, but it was sent to the test environment service for verification. Send it to the production environment service instead.'
+	21008: 'This receipt is from the production receipt, but it was sent to the test environment service for verification. Send it to the production environment service instead.',
+	21009: 'Internal data access error. Try again later.',
+	21010: 'The user account cannot be found or has been deleted.'
 };
 
 function getReceiptFieldValue(receipt, field) {
@@ -78,19 +80,33 @@ function parseResult(result) {
 			productId = lastReceipt.product_id;
 			transactionId = lastReceipt.transaction_id;
 			purchaseDate = parseTime(lastReceipt.purchase_date_ms);
-			expirationDate = parseTime(lastReceipt.expires_date_ms || lastReceipt.expires_date);
+			expirationDate = parseTime(
+				lastReceipt.expires_date_ms ||
+				lastReceipt.expires_date
+			);
 		} else if (result.latest_receipt_info && result.latest_receipt_info.transaction_id) {
 			latestReceiptInfo = [result.latest_receipt_info];
 
 			productId = result.latest_receipt_info.product_id;
 			transactionId = result.latest_receipt_info.transaction_id;
 			purchaseDate = parseTime(result.latest_receipt_info.purchase_date_ms);
 			expirationDate = parseTime(
-				result.latest_receipt_info.expires_date_ms || result.latest_receipt_info.expires_date
+				result.latest_receipt_info.expires_date_ms ||
+				result.latest_receipt_info.expires_date
 			);
 		}
 	}
 
+	// If cancellation date is available it means that Apple Customer Support refunded subscription payment.
+	// From Apple:
+	// To check whether a purchase has been canceled by Apple Customer Support, look for the
+	// Cancellation Date field in the receipt. If the field contains a date, regardless of the
+	// subscription’s expiration date, the purchase has been canceled. With respect to providing
+	// content or service, treat a canceled transaction the same as if no purchase had ever been made.
+	if (latestExpiredReceiptInfo && latestExpiredReceiptInfo.cancellation_date_ms) {
+		expirationDate = parseTime(latestExpiredReceiptInfo.cancellation_date_ms);
+	}
+
 	return {
 		receipt: result.receipt,
 		latestReceiptInfo,

lib/google/index.js

@@ -41,6 +41,17 @@ function validatePaymentAndParseKeyObject(payment) {
 	return keyObject;
 }
 
+function validateDeferralInfo(deferralInfo) {
+	assert.equal(typeof deferralInfo, 'object', 'deferralInfo must be an object');
+	assert.equal(typeof deferralInfo.expectedExpiryTimeMillis, 'number', 'expectedExpiryTimeMillis must be a number');
+	assert.equal(typeof deferralInfo.desiredExpiryTimeMillis, 'number', 'desiredExpiryTimeMillis must be a number');
+
+	assert(deferralInfo.desiredExpiryTimeMillis > deferralInfo.expectedExpiryTimeMillis, 'desiredExpiryTimeMillis must be greater than expectedExpiryTimeMillis');
+
+	return deferralInfo;
+}
+
+
 exports.verifyPayment = function (payment, cb) {
 	let keyObject;
 
@@ -133,3 +144,52 @@ exports.cancelSubscription = function (payment, cb) {
 		});
 	});
 };
+
+
+exports.deferSubscription = function (payment, deferralInfo, cb) {
+	let keyObject;
+	const options = {};
+
+	try {
+		keyObject = validatePaymentAndParseKeyObject(payment);
+		options.json = {
+			deferralInfo: validateDeferralInfo(deferralInfo)
+		};
+	} catch (error) {
+		return process.nextTick(function () {
+			cb(error);
+		});
+	}
+
+	jwt.getToken(keyObject.client_email, keyObject.private_key, apiUrls.publisherScope, function (error, token) {
+		if (error) {
+			return cb(error);
+		}
+
+		const requestUrl = apiUrls.purchasesSubscriptionsDefer(
+			payment.packageName,
+			payment.productId,
+			payment.receipt,
+			token
+		);
+
+		https.post(requestUrl, options, function (error, res, resultString) {
+			if (error) {
+				return cb(error);
+			}
+
+			if (res.statusCode !== 200) {
+				return cb(new Error(`Received ${res.statusCode} status code with body: ${resultString}`));
+			}
+
+			var resultObject;
+			try {
+				resultObject = JSON.parse(resultString);
+			} catch (e) {
+				return cb(e);
+			}
+
+			return cb(null, resultObject);
+		});
+	});
+};

lib/google/urls.js

@@ -38,8 +38,6 @@ exports.purchasesSubscriptionsGet = function (packageName, productId, receipt, a
 	);
 };
 
-
-// Android Subscriptions URLs & generators
 exports.purchasesSubscriptionsCancel = function (packageName, productId, receipt, accessToken) {
 	const urlFormat = 'https://www.googleapis.com/androidpublisher/v3/applications/%s/purchases/subscriptions/%s/tokens/%s:cancel?access_token=%s';
 
@@ -51,3 +49,16 @@ exports.purchasesSubscriptionsCancel = function (packageName, productId, receipt
 		encodeURIComponent(accessToken)   // API access token
 	);
 };
+
+// Android Subscriptions URLs & generators
+exports.purchasesSubscriptionsDefer = function (packageName, productId, receipt, accessToken) {
+	const urlFormat = 'https://www.googleapis.com/androidpublisher/v3/applications/%s/purchases/subscriptions/%s/tokens/%s:defer?access_token=%s';
+
+	return util.format(
+		urlFormat,
+		encodeURIComponent(packageName),  // application package name
+		encodeURIComponent(productId),    // productId
+		encodeURIComponent(receipt),      // purchase token
+		encodeURIComponent(accessToken)   // API access token
+	);
+};