restore scroll position after adding to cart

backend/src/modules/storefrontCart/controllers/StorefrontCartController.ts

@@ -100,7 +100,7 @@ export class StorefrontCartController {
             text: 'Added to cart.'
         });
 
-        res.redirect(HttpStatus.FOUND, safeInternalShopRedirectPath(req));
+        res.redirect(HttpStatus.FOUND, this.buildAddToCartRedirectPath(req, variantId));
     }
 
     @Post('shop/cart/product/update')
@@ -189,4 +189,18 @@ export class StorefrontCartController {
             this.cartCookieService.setCart(req, res, cartMutation);
         }
     }
+
+    private buildAddToCartRedirectPath(req: Request, variantId: string): string {
+        const redirectPath = safeInternalShopRedirectPath(req);
+        const pathname = redirectPath.split('?')[0] ?? redirectPath;
+        const isProductsIndexPath = pathname === '/' || pathname.startsWith('/shop/categories/');
+
+        if (!isProductsIndexPath) {
+            return redirectPath;
+        }
+
+        const anchor = `product-card-${variantId}`;
+
+        return `${redirectPath}#${anchor}`;
+    }
 }