Developer Advisory: Resolving Jetpack Boost and Checkout Blocks Conflicts in WC 8.9

Overview

After the release of WooCommerce 8.9, we received reports from users who encountered the following issues:

• Jetpack Boost’s “Concatenate JS” feature is breaking the Cart and Checkout blocks, as well as the Mini-cart block.
• Checkout block shows warning Warning: foreach() argument must be of type array|object, string given when a guest session is loaded after upgrading to 8.9.

We are currently investigating the following issues. You can monitor their progress here:

• Checkout block shows warning after upgrading to 8.9 (#47485)
• Cart & Checkout Blocks not working on stores with WC 8.9 + Jetpack Boost’s “Concatenate JS” feature (#47492)
• Mini-Cart block doesn’t load when certain conditions are met and Jetpack Boost’s “Concatenate JS” is enabled (#47495)

How can I tell if this affects me?

If your store is using the Cart, Checkout, or Mini Cart blocks with Jetpack Boost’s “Concatenate JS” feature enabled and has upgraded to WooCommerce 8.9, some of your customers may encounter a fatal error when interacting with one of these blocks.

If your store is using the Checkout block and had recently upgraded to WooCommerce 8.9, you could get multiple warnings in your logs:

> Warning: foreach() argument must be of type array|object, string given in wp-content/plugins/woocommerce/includes/data-stores/class-wc-customer-data-store-session.php on line 152

What action should I take?

If you are experiencing any of these issues, here’s what you can do.

If you or your customers are affected by the fatal error of the Cart, Checkout, or Mini Cart blocks:

• Update Jetpack Boost to version 3.3.1.

If you see multiple warnings about /class-wc-customer-data-store-session.php in your logs:

• It does not involve any risk for your store and clients. The issue will be fixed on the upcoming point release that we are aiming to release soon.

What happens next?

We are aiming to release WooCommerce 8.9.1 very soon to patch the second issue. We will make an announcement here on the WooCommerce Developer Blog.

Regarding the first issue, it can be solved by updating Jetpack Boost to its latest version.