retain paid plan until period end on cancellation

api/package.json

@@ -90,6 +90,9 @@
     "transform": {
       "^.+\\.(t|j)s$": "ts-jest"
     },
+    "moduleNameMapper": {
+      "^src/(.*)$": "<rootDir>/$1"
+    },
     "collectCoverageFrom": [
       "**/*.(t|j)s"
     ],

api/src/billing/billing.controller.spec.ts

@@ -0,0 +1,165 @@
+import { Test, TestingModule } from '@nestjs/testing'
+import { BillingController } from './billing.controller'
+import { BillingService } from './billing.service'
+import { BillingNotificationsService } from './billing-notifications.service'
+import { AuthGuard } from '../auth/guards/auth.guard'
+
+describe('BillingController - handlePolarWebhook', () => {
+  let controller: BillingController
+
+  const mockBillingService = {
+    validatePolarWebhookPayload: jest.fn(),
+    storePolarWebhookPayload: jest.fn(),
+    switchPlan: jest.fn(),
+    cancelSubscription: jest.fn(),
+    revokeSubscription: jest.fn(),
+  }
+  const mockBillingNotifications = {
+    listForUser: jest.fn(),
+  }
+
+  const req = { headers: { 'webhook-id': 'wh_1' } }
+
+  // Builds a Polar webhook payload. `data` overrides let each test tweak
+  // the event type, ids, and the cancel/period fields under test.
+  const makePayload = (type: string, data: Record<string, any> = {}) => ({
+    type,
+    data: {
+      id: 'sub_123',
+      product: { id: 'prod_pro_monthly' },
+      customer: { externalId: 'user_ext_1' },
+      metadata: { userId: 'user_meta_1' },
+      status: 'active',
+      currentPeriodStart: '2026-06-17T00:00:00.000Z',
+      currentPeriodEnd: '2026-07-17T00:00:00.000Z',
+      cancelAtPeriodEnd: false,
+      createdAt: '2026-06-17T00:00:00.000Z',
+      canceledAt: null,
+      amount: 1900,
+      currency: 'usd',
+      recurringInterval: 'month',
+      customerId: 'cust_1',
+      ...data,
+    },
+  })
+
+  const handle = async (payload: any) => {
+    mockBillingService.validatePolarWebhookPayload.mockResolvedValue(payload)
+    await controller.handlePolarWebhook({ any: 'rawBody' }, req)
+  }
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [BillingController],
+      providers: [
+        { provide: BillingService, useValue: mockBillingService },
+        {
+          provide: BillingNotificationsService,
+          useValue: mockBillingNotifications,
+        },
+      ],
+    })
+      // The webhook route is unguarded, but the controller's other routes use
+      // AuthGuard (JwtService/UsersService/AuthService). Override it so the
+      // test module doesn't need to wire up the whole auth stack.
+      .overrideGuard(AuthGuard)
+      .useValue({ canActivate: () => true })
+      .compile()
+
+    controller = module.get<BillingController>(BillingController)
+
+    jest.clearAllMocks()
+    mockBillingService.storePolarWebhookPayload.mockResolvedValue(undefined)
+    mockBillingService.switchPlan.mockResolvedValue({ success: true })
+    mockBillingService.cancelSubscription.mockResolvedValue({ success: true })
+    mockBillingService.revokeSubscription.mockResolvedValue({ success: true })
+  })
+
+  it('validates and stores every incoming payload', async () => {
+    await handle(makePayload('subscription.created'))
+
+    expect(mockBillingService.validatePolarWebhookPayload).toHaveBeenCalledWith(
+      { any: 'rawBody' },
+      req.headers,
+    )
+    expect(mockBillingService.storePolarWebhookPayload).toHaveBeenCalledTimes(1)
+  })
+
+  it('routes subscription.created to switchPlan with the period fields', async () => {
+    await handle(makePayload('subscription.created'))
+
+    expect(mockBillingService.switchPlan).toHaveBeenCalledWith(
+      expect.objectContaining({
+        userId: 'user_meta_1',
+        newPlanPolarProductId: 'prod_pro_monthly',
+        currentPeriodEnd: '2026-07-17T00:00:00.000Z',
+        cancelAtPeriodEnd: false,
+      }),
+    )
+    expect(mockBillingService.cancelSubscription).not.toHaveBeenCalled()
+    expect(mockBillingService.revokeSubscription).not.toHaveBeenCalled()
+  })
+
+  it('routes subscription.updated to switchPlan, forwarding cancelAtPeriodEnd', async () => {
+    await handle(makePayload('subscription.updated', { cancelAtPeriodEnd: true }))
+
+    expect(mockBillingService.switchPlan).toHaveBeenCalledWith(
+      expect.objectContaining({
+        cancelAtPeriodEnd: true,
+        currentPeriodEnd: '2026-07-17T00:00:00.000Z',
+      }),
+    )
+  })
+
+  it('routes subscription.canceled to cancelSubscription, forwarding the cancel/period fields and NOT downgrading', async () => {
+    await handle(
+      makePayload('subscription.canceled', { cancelAtPeriodEnd: true }),
+    )
+
+    expect(mockBillingService.cancelSubscription).toHaveBeenCalledWith({
+      userId: 'user_meta_1',
+      polarProductId: 'prod_pro_monthly',
+      cancelAtPeriodEnd: true,
+      currentPeriodEnd: '2026-07-17T00:00:00.000Z',
+      status: 'active',
+    })
+    // A scheduled cancellation must not route to the downgrade or switchPlan.
+    expect(mockBillingService.revokeSubscription).not.toHaveBeenCalled()
+    expect(mockBillingService.switchPlan).not.toHaveBeenCalled()
+  })
+
+  it('routes the alternate spelling subscription.cancelled to cancelSubscription', async () => {
+    await handle(makePayload('subscription.cancelled'))
+
+    expect(mockBillingService.cancelSubscription).toHaveBeenCalledTimes(1)
+    expect(mockBillingService.revokeSubscription).not.toHaveBeenCalled()
+  })
+
+  it('routes subscription.revoked to revokeSubscription (the real downgrade)', async () => {
+    await handle(makePayload('subscription.revoked'))
+
+    expect(mockBillingService.revokeSubscription).toHaveBeenCalledWith({
+      userId: 'user_meta_1',
+      polarProductId: 'prod_pro_monthly',
+    })
+    expect(mockBillingService.cancelSubscription).not.toHaveBeenCalled()
+  })
+
+  it('does not mutate any subscription for an unhandled event type', async () => {
+    await handle(makePayload('checkout.created'))
+
+    expect(mockBillingService.switchPlan).not.toHaveBeenCalled()
+    expect(mockBillingService.cancelSubscription).not.toHaveBeenCalled()
+    expect(mockBillingService.revokeSubscription).not.toHaveBeenCalled()
+    // ...but the payload is still validated and stored.
+    expect(mockBillingService.storePolarWebhookPayload).toHaveBeenCalledTimes(1)
+  })
+
+  it('falls back to customer.externalId when metadata.userId is absent', async () => {
+    await handle(makePayload('subscription.revoked', { metadata: {} }))
+
+    expect(mockBillingService.revokeSubscription).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: 'user_ext_1' }),
+    )
+  })
+})

api/src/billing/billing.controller.ts

@@ -101,13 +101,30 @@ export class BillingController {
       case 'subscription.cancelled':
       // @ts-ignore
       case 'subscription.canceled':
-      // case 'subscription.revoked':
         console.log('polar webhook event', payload.type)
         console.log(payload)
+        // Cancellation is SCHEDULED here — access continues until period end.
+        // Record the intent without downgrading; the actual downgrade happens
+        // on "subscription.revoked".
         await this.billingService.cancelSubscription({
           userId: (payload.data?.metadata?.userId ||
             payload.data?.customer?.externalId) as string,
           polarProductId: payload.data?.product?.id,
+          cancelAtPeriodEnd: payload.data?.cancelAtPeriodEnd,
+          currentPeriodEnd: payload.data?.currentPeriodEnd,
+          status: payload.data?.status,
+        })
+        break
+
+      // @ts-ignore
+      case 'subscription.revoked':
+        console.log('polar webhook event', payload.type)
+        console.log(payload)
+        // Access should actually end now — perform the real downgrade.
+        await this.billingService.revokeSubscription({
+          userId: (payload.data?.metadata?.userId ||
+            payload.data?.customer?.externalId) as string,
+          polarProductId: payload.data?.product?.id,
         })
         break
       default:

api/src/billing/billing.service.spec.ts

@@ -0,0 +1,141 @@
+import { Test, TestingModule } from '@nestjs/testing'
+import { getModelToken } from '@nestjs/mongoose'
+import { Types } from 'mongoose'
+import { BillingService } from './billing.service'
+import { Plan } from './schemas/plan.schema'
+import { Subscription } from './schemas/subscription.schema'
+import { User } from '../users/schemas/user.schema'
+import { SMS } from '../gateway/schemas/sms.schema'
+import { PolarWebhookPayload } from './schemas/polar-webhook-payload.schema'
+import { CheckoutSession } from './schemas/checkout-session.schema'
+import { BillingNotificationsService } from './billing-notifications.service'
+
+describe('BillingService - cancellation handling', () => {
+  let service: BillingService
+
+  // 24-hex string so `new Types.ObjectId(userId)` succeeds.
+  const userId = '507f1f77bcf86cd799439011'
+  const proPlan = { _id: 'plan_pro', name: 'pro' }
+  const polarProductId = 'prod_pro_monthly'
+
+  const mockPlanModel = {
+    findOne: jest.fn(),
+  }
+  const mockSubscriptionModel = {
+    updateOne: jest.fn(),
+  }
+  const emptyModel = {}
+  const mockBillingNotifications = {}
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        BillingService,
+        { provide: getModelToken(Plan.name), useValue: mockPlanModel },
+        {
+          provide: getModelToken(Subscription.name),
+          useValue: mockSubscriptionModel,
+        },
+        { provide: getModelToken(User.name), useValue: emptyModel },
+        { provide: getModelToken(SMS.name), useValue: emptyModel },
+        {
+          provide: getModelToken(PolarWebhookPayload.name),
+          useValue: emptyModel,
+        },
+        {
+          provide: getModelToken(CheckoutSession.name),
+          useValue: emptyModel,
+        },
+        {
+          provide: BillingNotificationsService,
+          useValue: mockBillingNotifications,
+        },
+      ],
+    }).compile()
+
+    service = module.get<BillingService>(BillingService)
+
+    jest.clearAllMocks()
+    mockPlanModel.findOne.mockResolvedValue(proPlan)
+    mockSubscriptionModel.updateOne.mockResolvedValue({ modifiedCount: 1 })
+  })
+
+  describe('cancelSubscription', () => {
+    it('records the scheduled cancellation WITHOUT downgrading (keeps the plan active)', async () => {
+      const currentPeriodEnd = new Date('2026-07-17T00:00:00.000Z')
+
+      await service.cancelSubscription({
+        userId,
+        polarProductId,
+        cancelAtPeriodEnd: true,
+        currentPeriodEnd,
+        status: 'active',
+      })
+
+      expect(mockSubscriptionModel.updateOne).toHaveBeenCalledTimes(1)
+      const [filter, update] = mockSubscriptionModel.updateOne.mock.calls[0]
+
+      // Filter targets the user's active subscription for this plan.
+      expect(filter).toEqual({
+        user: expect.any(Types.ObjectId),
+        plan: proPlan._id,
+        isActive: true,
+      })
+
+      // The fix: the cancellation is recorded with the real period end, and
+      // the subscription stays active. It must NOT flip isActive to false.
+      expect(update).toEqual({
+        cancelAtPeriodEnd: true,
+        currentPeriodEnd,
+        subscriptionEndDate: currentPeriodEnd,
+        status: 'active',
+      })
+      expect(update).not.toHaveProperty('isActive')
+    })
+
+    it('defaults cancelAtPeriodEnd to true and omits period fields when not provided', async () => {
+      await service.cancelSubscription({ userId, polarProductId })
+
+      const [, update] = mockSubscriptionModel.updateOne.mock.calls[0]
+      expect(update).toEqual({ cancelAtPeriodEnd: true })
+      expect(update).not.toHaveProperty('currentPeriodEnd')
+      expect(update).not.toHaveProperty('subscriptionEndDate')
+      expect(update).not.toHaveProperty('isActive')
+    })
+
+    it('throws when no plan matches the Polar product id', async () => {
+      mockPlanModel.findOne.mockResolvedValue(null)
+
+      await expect(
+        service.cancelSubscription({ userId, polarProductId: 'unknown' }),
+      ).rejects.toThrow('No plan found for product ID: unknown')
+      expect(mockSubscriptionModel.updateOne).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('revokeSubscription', () => {
+    it('performs the real downgrade by deactivating the subscription', async () => {
+      await service.revokeSubscription({ userId, polarProductId })
+
+      expect(mockSubscriptionModel.updateOne).toHaveBeenCalledTimes(1)
+      const [filter, update] = mockSubscriptionModel.updateOne.mock.calls[0]
+
+      expect(filter).toEqual({
+        user: expect.any(Types.ObjectId),
+        plan: proPlan._id,
+        isActive: true,
+      })
+      expect(update.isActive).toBe(false)
+      expect(update.subscriptionEndDate).toBeInstanceOf(Date)
+    })
+
+    it('throws when no plan matches the Polar product id', async () => {
+      mockPlanModel.findOne.mockResolvedValue(null)
+
+      await expect(
+        service.revokeSubscription({ userId, polarProductId: 'unknown' }),
+      ).rejects.toThrow('No plan found for product ID: unknown')
+      expect(mockSubscriptionModel.updateOne).not.toHaveBeenCalled()
+    })
+  })
+})