fix(api): keep premium paid for after a subscription cancels (#2875)

fluxer_api/src/api/worker/tasks/ProcessPremiumStateReconciliationQueue.ts

@@ -8,6 +8,7 @@ import {getBillingRepository} from '@app/api/middleware/ServiceRegistry';
 import type {User} from '@app/api/models/User';
 import {canProvisionPremiumFromSubscriptionStatus} from '@app/api/stripe/StripeSubscriptionAccessPolicy';
 import {
+	getInvoiceLatestLinePeriodEnd,
 	getPrimarySubscriptionItem,
 	getSubscriptionPremiumPeriodEnd,
 	getSubscriptionStartDate,
@@ -142,6 +143,39 @@ function trackMostRecentTerminalSubscription(
 	return current;
 }
 
+const PAID_INVOICE_LOOKUP_LIMIT = 10;
+
+async function getPaidThroughFromSubscriptionInvoices(
+	stripe: Stripe,
+	subscription: Stripe.Subscription | null,
+): Promise<Date | null> {
+	if (!subscription) {
+		return null;
+	}
+	let invoices: Stripe.ApiList<Stripe.Invoice>;
+	try {
+		invoices = await stripe.invoices.list({
+			subscription: subscription.id,
+			status: 'paid',
+			limit: PAID_INVOICE_LOOKUP_LIMIT,
+		});
+	} catch (error) {
+		Logger.warn(
+			{subscriptionId: subscription.id, error},
+			'Failed to list paid invoices while reconciling premium state; not stripping on incomplete data',
+		);
+		throw error;
+	}
+	let paidThrough: Date | null = null;
+	for (const invoice of invoices.data) {
+		const periodEnd = getInvoiceLatestLinePeriodEnd(invoice);
+		if (periodEnd && (paidThrough === null || periodEnd.getTime() > paidThrough.getTime())) {
+			paidThrough = periodEnd;
+		}
+	}
+	return paidThrough;
+}
+
 async function getEffectiveActiveStripeSubscription(
 	stripe: Stripe,
 	user: User,
@@ -240,17 +274,28 @@ async function reconcileUserPremiumStateFromStripe(params: {userId: UserID; stri
 		if (hasStalePremium && !hasNonStripePremium) {
 			const patch: Partial<UserRow> = {};
 			let effectivePremiumUntil = getEffectivePremiumUntil(user);
+			const paidThrough = await getPaidThroughFromSubscriptionInvoices(stripe, mostRecentTerminalSubscription);
 			if (mostRecentTerminalSubscription?.ended_at && user.premiumUntil) {
 				const subscriptionEndedAt = new Date(mostRecentTerminalSubscription.ended_at * 1000);
-				if (subscriptionEndedAt.getTime() < user.premiumUntil.getTime()) {
-					patch.premium_until = subscriptionEndedAt;
-					patch.premium_grace_ends_at = subscriptionEndedAt;
+				const entitlementEnd =
+					paidThrough && paidThrough.getTime() > subscriptionEndedAt.getTime() ? paidThrough : subscriptionEndedAt;
+				if (entitlementEnd.getTime() < user.premiumUntil.getTime()) {
+					patch.premium_until = entitlementEnd;
+					patch.premium_grace_ends_at = entitlementEnd;
 					effectivePremiumUntil = getEffectivePremiumUntil({
-						premiumUntil: subscriptionEndedAt,
+						premiumUntil: entitlementEnd,
 						premiumGiftExtensionEndsAt: user.premiumGiftExtensionEndsAt,
 					});
 				}
 			}
+			if (paidThrough && (effectivePremiumUntil == null || paidThrough.getTime() > effectivePremiumUntil.getTime())) {
+				patch.premium_until = paidThrough;
+				patch.premium_grace_ends_at = paidThrough;
+				effectivePremiumUntil = getEffectivePremiumUntil({
+					premiumUntil: paidThrough,
+					premiumGiftExtensionEndsAt: user.premiumGiftExtensionEndsAt,
+				});
+			}
 			const hasFutureLocalEntitlement = effectivePremiumUntil != null && Date.now() <= effectivePremiumUntil.getTime();
 			if (hasFutureLocalEntitlement) {
 				if (user.premiumWillCancel !== true) {

fluxer_api/src/api/worker/tests/ProcessPremiumStateReconciliationQueue.test.ts

@@ -1,7 +1,10 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
 import {createUserID} from '@app/api/BrandedTypes';
+import type {UserRow} from '@app/api/database/types/UserTypes';
+import {EMPTY_USER_ROW} from '@app/api/database/types/UserTypes';
 import {PremiumStateReconciliationQueueService} from '@app/api/infrastructure/PremiumStateReconciliationQueueService';
+import {User} from '@app/api/models/User';
 import {MockKVProvider} from '@app/api/test/mocks/MockKVProvider';
 import {NoopLogger} from '@app/api/test/mocks/NoopLogger';
 import type {UserRepository} from '@app/api/user/repositories/UserRepository';
@@ -13,6 +16,77 @@ import {afterEach, describe, expect, test} from 'vitest';
 
 const USER_ID = createUserID(834271905123471361n);
 const ONE_HOUR_MS = 60 * 60 * 1000;
+const ONE_DAY_MS = 24 * ONE_HOUR_MS;
+
+function createPremiumUser(overrides: Partial<UserRow> = {}): User {
+	return new User({
+		...EMPTY_USER_ROW,
+		user_id: USER_ID,
+		username: 'paidlate',
+		discriminator: 1,
+		premium_type: 1,
+		premium_since: new Date(Date.now() - 200 * ONE_DAY_MS),
+		premium_until: new Date(Date.now() + 20 * ONE_DAY_MS),
+		stripe_customer_id: 'cus_test',
+		stripe_subscription_id: 'sub_test',
+		...overrides,
+	});
+}
+
+function createCancelledSubscription(endedAtMs: number): Stripe.Subscription {
+	return {
+		id: 'sub_test',
+		status: 'canceled',
+		customer: 'cus_test',
+		ended_at: Math.floor(endedAtMs / 1000),
+		canceled_at: Math.floor(endedAtMs / 1000),
+		cancel_at: null,
+		cancel_at_period_end: false,
+		trial_end: null,
+		start_date: Math.floor((Date.now() - 200 * ONE_DAY_MS) / 1000),
+		items: {data: []},
+	} as unknown as Stripe.Subscription;
+}
+
+function createPaidInvoice(periodEndMs: number): Stripe.Invoice {
+	return {
+		id: 'in_test',
+		status: 'paid',
+		lines: {data: [{period: {start: 0, end: Math.floor(periodEndMs / 1000)}}]},
+	} as unknown as Stripe.Invoice;
+}
+
+function createStripeStub(subscription: Stripe.Subscription, invoices: Array<Stripe.Invoice>): Stripe {
+	return {
+		subscriptions: {
+			retrieve: async () => subscription,
+			list: async () => ({data: [subscription]}),
+		},
+		invoices: {
+			list: async () => ({data: invoices}),
+		},
+	} as unknown as Stripe;
+}
+
+function createCapturingDeps(user: User): {
+	userRepository: UserRepository;
+	patches: Array<Partial<UserRow>>;
+	extras: Record<string, unknown>;
+} {
+	const patches: Array<Partial<UserRow>> = [];
+	const userRepository = {
+		findUnique: async () => user,
+		patchUpsert: async (_id: unknown, patch: Partial<UserRow>) => {
+			patches.push(patch);
+			return new User({...user.toRow(), ...patch});
+		},
+	} as unknown as UserRepository;
+	const extras = {
+		userCacheService: {setUserPartialResponseFromUserInBackground: () => {}},
+		gatewayService: {dispatchPresence: async () => {}},
+	};
+	return {userRepository, patches, extras};
+}
 
 function createHelpers(): WorkerTaskHelpers {
 	return {
@@ -151,4 +225,78 @@ describe('processPremiumStateReconciliationQueue', () => {
 		expect(findUniqueCalls).toBe(1);
 		expect(await queueService.getQueueSize()).toBe(0);
 	});
+
+	test('keeps premium when a paid invoice covers a period beyond the cancellation', async () => {
+		const queueService = createQueueService();
+		await queueService.enqueueUser(USER_ID, new Date(Date.now() - 1000));
+
+		const endedAtMs = Date.now() - 3 * ONE_DAY_MS;
+		const paidThroughMs = Math.floor((Date.now() + 20 * ONE_DAY_MS) / 1000) * 1000;
+		const user = createPremiumUser({premium_until: new Date(paidThroughMs)});
+		const {userRepository, patches, extras} = createCapturingDeps(user);
+
+		setWorkerDependenciesForTest({
+			premiumStateReconciliationQueueService: queueService,
+			stripe: createStripeStub(createCancelledSubscription(endedAtMs), [createPaidInvoice(paidThroughMs)]),
+			userRepository,
+			...extras,
+		});
+
+		await processPremiumStateReconciliationQueue({}, createHelpers());
+
+		expect(patches).toHaveLength(1);
+		const patch = patches[0];
+		expect(patch.premium_type).toBeUndefined();
+		expect(patch.premium_since).toBeUndefined();
+		expect(patch.premium_until).toBeUndefined();
+		expect(patch.premium_will_cancel).toBe(true);
+	});
+
+	test('extends premium to the paid period instead of the cancellation date', async () => {
+		const queueService = createQueueService();
+		await queueService.enqueueUser(USER_ID, new Date(Date.now() - 1000));
+
+		const endedAtMs = Date.now() - 3 * ONE_DAY_MS;
+		const paidThroughMs = Date.now() + 20 * ONE_DAY_MS;
+		const user = createPremiumUser({premium_until: new Date(Date.now() + 5 * ONE_DAY_MS)});
+		const {userRepository, patches, extras} = createCapturingDeps(user);
+
+		setWorkerDependenciesForTest({
+			premiumStateReconciliationQueueService: queueService,
+			stripe: createStripeStub(createCancelledSubscription(endedAtMs), [createPaidInvoice(paidThroughMs)]),
+			userRepository,
+			...extras,
+		});
+
+		await processPremiumStateReconciliationQueue({}, createHelpers());
+
+		expect(patches).toHaveLength(1);
+		expect(patches[0].premium_until).toEqual(new Date(Math.floor(paidThroughMs / 1000) * 1000));
+		expect(patches[0].premium_will_cancel).toBe(true);
+		expect(patches[0].premium_type).toBeUndefined();
+	});
+
+	test('still strips premium when no paid invoice covers a future period', async () => {
+		const queueService = createQueueService();
+		await queueService.enqueueUser(USER_ID, new Date(Date.now() - 1000));
+
+		const endedAtMs = Date.now() - 3 * ONE_DAY_MS;
+		const paidThroughMs = Date.now() - 3 * ONE_DAY_MS;
+		const user = createPremiumUser();
+		const {userRepository, patches, extras} = createCapturingDeps(user);
+
+		setWorkerDependenciesForTest({
+			premiumStateReconciliationQueueService: queueService,
+			stripe: createStripeStub(createCancelledSubscription(endedAtMs), [createPaidInvoice(paidThroughMs)]),
+			userRepository,
+			...extras,
+		});
+
+		await processPremiumStateReconciliationQueue({}, createHelpers());
+
+		expect(patches).toHaveLength(1);
+		expect(patches[0].premium_type).toBeNull();
+		expect(patches[0].premium_until).toBeNull();
+		expect(patches[0].premium_since).toBeNull();
+	});
 });