feat: compare previous email on customer updated

Previously we were comparing two emails that were always identical
because the user tied to the Merchant Customer record had already been
updated. Because of this, an email was never getting sent to the new
user.

packages/skill-api/src/core/services/process-stripe-webhook.ts

@@ -285,25 +285,40 @@ export const processStripeWebhook = async (
       },
     })
 
-    const user = merchantCustomer?.user
+    const currentUser = merchantCustomer?.user
 
-    if (user) {
-      const currentEmail = user.email
-      const {email, name} = eventObject
+    if (currentUser) {
+      const {email: targetEmail, name} = z
+        .object({
+          email: z.string(),
+          name: z.string().optional(),
+        })
+        .parse(eventObject)
+
+      const {previous_attributes} = z
+        .object({
+          previous_attributes: z
+            .object({email: z.string().optional()})
+            .optional(),
+        })
+        .parse(event.data)
+
+      const previousEmail = previous_attributes?.email
+
+      const transferringToDifferentUser = previousEmail
+        ? targetEmail.toLowerCase() !== previousEmail.toLowerCase()
+        : false
 
-      const {user: updateUser} = await findOrCreateUser(email, name)
+      const {user: updateUser} = await findOrCreateUser(targetEmail, name)
 
       await transferPurchasesToNewUser({
         merchantCustomerId: merchantCustomer.id,
         userId: updateUser.id,
       })
 
-      if (
-        currentEmail.toLowerCase() !== email.toLowerCase() &&
-        nextAuthOptions
-      ) {
+      if (transferringToDifferentUser && nextAuthOptions) {
         await sendServerEmail({
-          email,
+          email: targetEmail,
           callbackUrl: `${process.env.NEXTAUTH_URL}`,
           nextAuthOptions,
         })