Order total breaks after applying a promo code

Tester: Damilola Afolabi
Campaign: Northwind Storefront Checkout Refresh
Environment: Web
Time spent: 24m 0s

Summary

Applying PROOF10 at checkout throws a TypeError and the order total renders as $NaN. Confirmed via console error and the failed /api/cart/apply-promo request.

Evidence (4 log entries)

09:06:02 AMconsole
TypeError: Cannot read properties of undefined (reading 'total')
checkout-summary.js:118
09:11:30 AMnetwork
POST /api/cart/apply-promo → 500
09:18:12 AMnote
Order total shows $NaN after promo applied
09:18:30 AMscreenshot
Checkout summary showing $NaN total
s1l6.png
Mock capture — no real upload in this demo

Submitted 9/1/2026, 9:27:40 AM · Confidential — internal use only