subs: support mixing IAP and LN purchases

Also add test coverage.

Previously, making an IAP purchase on an account with some remaining
time credit would wipe away the remaining credits they had.

This commit fixes this and adds an automated test to verify this edge
case.

Testing: Unit tests passing
Signed-off-by: Daniel D’Aquino <[email protected]>
Reviewed-by: William Casarin <[email protected]>
Signed-off-by: William Casarin <[email protected]>

src/router_config.js

@@ -1,5 +1,5 @@
 const { json_response, simple_response, error_response, invalid_request, unauthorized_response } = require('./server_helpers')
-const { create_account, get_account_info_payload, check_account, get_account, put_account, get_account_and_user_id, get_user_uuid } = require('./user_management')
+const { create_account, get_account_info_payload, check_account, get_account, put_account, get_account_and_user_id, get_user_uuid, bumpy_set_expiry } = require('./user_management')
 const handle_translate = require('./translate')
 const verify_receipt = require('./app_store_receipt_verifier').verify_receipt
 const bodyParser = require('body-parser')
@@ -117,19 +117,13 @@ function config_router(app) {
  return
  }
 
- let account = get_account(app, pubkey)
- if (!account) {
- let result = create_account(app, req.authorized_pubkey, null)
-
- if (result.request_error) {
- invalid_request(res, result.request_error)
- return
- }
- account = result.account
+ const { account: new_account, request_error } = bumpy_set_expiry(app, req.authorized_pubkey, expiry_date)
+ if (request_error) {
+ error_response(res, request_error)
+ return
  }
-
- account.expiry = expiry_date
- const { user_id } = put_account(app, pubkey, account)
+
+ let { account, user_id } = get_account_and_user_id(app, req.authorized_pubkey)
  json_response(res, get_account_info_payload(user_id, account))
  return
  })

src/user_management.js

@@ -91,6 +91,37 @@ function bump_expiry(api, pubkey, expiry_delta) {
  return { account: account, request_error: null }
 }
 
+/**
+ * Sets the expiry date to a fixed date, but also bumps the expiry date if there is any time left.
+ * It also creates the account if it doesn't exist already.
+ *
+ * @param {Object} api - The API object
+ * @param {string} pubkey - The public key of the user, hex encoded
+ * @param {number} expiry_date - The new expiry date
+*/
+function bumpy_set_expiry(api, pubkey, expiry_date) {
+ const account = get_account(api, pubkey)
+ if (!account) {
+ // Create account if it doesn't exist already
+ return create_account(api, pubkey, expiry_date)
+ }
+ if (!account.expiry) {
+ // Set expiry if it doesn't exist already
+ account.expiry = expiry_date
+ }
+ else if (account.expiry < current_time()) {
+ // Set new expiry if it has already expired
+ account.expiry = expiry_date
+ }
+ else if (account.expiry >= current_time()) {
+ // Accumulate expiry if it hasn't expired yet
+ const remaining_time = account.expiry - current_time()
+ account.expiry = expiry_date + remaining_time
+ }
+ put_account(api, pubkey, account)
+ return { account: account, request_error: null }
+}
+
 function get_account_info_payload(subscriber_number, account) {
  if (!account)
  return null
@@ -121,4 +152,4 @@ function get_user_uuid(api, pubkey) {
  return uuid
 }
 
-module.exports = { check_account, create_account, get_account_info_payload, bump_expiry, get_account, put_account, get_account_and_user_id, get_user_id_from_pubkey, get_user_uuid }
+module.exports = { check_account, create_account, get_account_info_payload, bump_expiry, get_account, put_account, get_account_and_user_id, get_user_id_from_pubkey, get_user_uuid, bumpy_set_expiry }

test/mixed_iap_ln_flow.test.js

@@ -0,0 +1,47 @@
+"use strict";
+// @ts-check
+
+const test = require('tap').test;
+const { PurpleTestController } = require('./controllers/purple_test_controller.js');
+const { PURPLE_ONE_MONTH } = require('../src/invoicing.js');
+const { MOCK_ACCOUNT_UUIDS, MOCK_IAP_DATES } = require('./controllers/mock_iap_controller.js');
+
+test('Mixed IAP/LN Flow — Expiry dates should be nicely handled', async (t) => {
+ // Set things up
+ const purple_api_controller = await PurpleTestController.new(t);
+ const user_uuid = MOCK_ACCOUNT_UUIDS[0]
+ const user_pubkey_1 = purple_api_controller.new_client();
+ purple_api_controller.set_account_uuid(user_pubkey_1, user_uuid); // Associate the pubkey with the user_uuid on the server
+
+ // Buy a one month subscription via LN flow 25 days before buying the IAP
+ purple_api_controller.set_current_time(MOCK_IAP_DATES[user_uuid].purchase_date - 60 * 60 * 24 * 25); // 25 days before the IAP purchase date
+ await purple_api_controller.ln_flow_buy_subscription(user_pubkey_1, PURPLE_ONE_MONTH);
+
+ // Check expiry
+ const account_info_response_1 = await purple_api_controller.clients[user_pubkey_1].get_account();
+ t.same(account_info_response_1.statusCode, 200);
+ t.same(account_info_response_1.body.expiry, purple_api_controller.current_time() + 30 * 24 * 60 * 60);
+ t.same(account_info_response_1.body.active, true);
+
+ // Fast forward 25 days, to the IAP purchase date
+ purple_api_controller.set_current_time(MOCK_IAP_DATES[user_uuid].purchase_date);
+
+ // Simulate IAP purchase on the iOS side
+ const receipt_base64 = purple_api_controller.iap.get_iap_receipt_data(user_uuid); // Get the receipt from the iOS side
+
+ // Send the receipt to the server to activate the account
+ const iap_response = await purple_api_controller.clients[user_pubkey_1].send_iap_receipt(user_uuid, receipt_base64);
+ t.same(iap_response.statusCode, 200);
+
+ // Read the account info now
+ const account_info_response = await purple_api_controller.clients[user_pubkey_1].get_account();
+ t.same(account_info_response.statusCode, 200);
+ // This user still had 5 days left on their subscription, so the expiry date should be 5 days after the IAP expiry date
+ // i.e. The user should not lose any credit for the time they had left on their subscription
+ t.same(account_info_response.body.expiry, MOCK_IAP_DATES[user_uuid].expiry_date + 5 * 24 * 60 * 60); 
+ t.same(account_info_response.body.active, true);
+
+ // TODO: Test other edge cases?
+
+ t.end();
+});