Simplify getStripeId. Move null checks into callers

Author: jahooma

packages/billing/src/subscription-webhooks.ts

@@ -53,15 +53,15 @@ export async function handleSubscriptionInvoicePaid(params: {
 
   if (!invoice.subscription) return
   const subscriptionId = getStripeId(invoice.subscription)
-  const customerId = getStripeId(invoice.customer)
 
-  if (!customerId) {
+  if (!invoice.customer) {
     logger.warn(
       { invoiceId: invoice.id },
       'Subscription invoice has no customer ID',
     )
     return
   }
+  const customerId = getStripeId(invoice.customer)
 
   const stripeSub = await stripeServer.subscriptions.retrieve(subscriptionId)
   const priceId = stripeSub.items.data[0]?.price.id
@@ -186,9 +186,9 @@ export async function handleSubscriptionInvoicePaymentFailed(params: {
 
   if (!invoice.subscription) return
   const subscriptionId = getStripeId(invoice.subscription)
-  const customerId = getStripeId(invoice.customer)
   let userId = null
-  if (customerId) {
+  if (invoice.customer) {
+    const customerId = getStripeId(invoice.customer)
     const user = await getUserByStripeCustomerId(customerId)
     userId = user?.id
   }

packages/internal/src/util/stripe.ts

@@ -7,10 +7,7 @@ import Stripe from 'stripe'
 /**
  * Extracts the ID string from a Stripe expandable field.
  */
-export function getStripeId(expandable: string | { id: string }): string
-export function getStripeId(expandable: string | { id: string } | null | undefined): string | undefined
-export function getStripeId(expandable: string | { id: string } | null | undefined): string | undefined {
-  if (expandable == null) return undefined
+export function getStripeId(expandable: string | { id: string }): string {
   return typeof expandable === 'string' ? expandable : expandable.id
 }
 

web/src/app/api/stripe/webhook/route.ts

@@ -392,15 +392,15 @@ const webhookHandler = async (req: NextRequest): Promise<NextResponse> => {
       }
       case 'charge.dispute.created': {
         const dispute = event.data.object as Stripe.Dispute
-        const chargeId = getStripeId(dispute.charge)
 
-        if (!chargeId) {
+        if (!dispute.charge) {
           logger.warn(
             { disputeId: dispute.id },
             'Dispute received without charge ID',
           )
           break
         }
+        const chargeId = getStripeId(dispute.charge)
 
         // Get the charge to find the customer
         const charge = await stripeServer.charges.retrieve(chargeId)
@@ -539,14 +539,16 @@ const webhookHandler = async (req: NextRequest): Promise<NextResponse> => {
       case 'invoice.paid': {
         const invoice = event.data.object as Stripe.Invoice
         if (invoice.subscription) {
-          const customerId = getStripeId(invoice.customer)
-          if (!customerId) {
+          if (!invoice.customer) {
             logger.warn(
               { invoiceId: invoice.id },
               'Subscription invoice has no customer — skipping',
             )
-          } else if (!(await isOrgCustomer(customerId))) {
-            await handleSubscriptionInvoicePaid({ invoice, logger })
+          } else {
+            const customerId = getStripeId(invoice.customer)
+            if (!(await isOrgCustomer(customerId))) {
+              await handleSubscriptionInvoicePaid({ invoice, logger })
+            }
           }
         } else {
           await handleInvoicePaid(invoice)
@@ -556,14 +558,16 @@ const webhookHandler = async (req: NextRequest): Promise<NextResponse> => {
       case 'invoice.payment_failed': {
         const invoice = event.data.object as Stripe.Invoice
         if (invoice.subscription) {
-          const customerId = getStripeId(invoice.customer)
-          if (!customerId) {
+          if (!invoice.customer) {
             logger.warn(
               { invoiceId: invoice.id },
               'Subscription invoice has no customer — skipping',
             )
-          } else if (!(await isOrgCustomer(customerId))) {
-            await handleSubscriptionInvoicePaymentFailed({ invoice, logger })
+          } else {
+            const customerId = getStripeId(invoice.customer)
+            if (!(await isOrgCustomer(customerId))) {
+              await handleSubscriptionInvoicePaymentFailed({ invoice, logger })
+            }
           }
         }
         if (