ASH WooCommerce Cookies

Woocommerce caching. This is Pantheon host specific.

Woocommerce Universal behavior (all hosts):

• Sets DONOTCACHEPAGE / no-cache headers on cart, checkout, and my-account pages. This is standard and expected — those pages should never be cached.

On Pantheon:

• WooCommerce also sets woocommerce_items_in_cart and woocommerce_cart_hash as HTTP cookies whenever someone has items in their cart. On most hosts this is harmless — those cookies are just used by JS for cart fragments.
• But Pantheon's Varnish treats any unrecognized cookie as a signal to bypass cache entirely. So once a visitor adds something to their cart, every single page they visit becomes uncacheable — not just cart/checkout.
• You also can't edit VCL on Pantheon, so you can't strip those cookies at the Varnish layer like you would on a self-managed Varnish setup.

What this plugin does:

1. Blocks woocommerce_items_in_cart and woocommerce_cart_hash from being set server-side.
2. Moves that data to sessionStorage via the JS patch so cart fragments still work.
3. Renames the session cookie with STYXKEY_ prefix so Pantheon treats it as cache-varying (separate buckets) instead of cache-busting.

Tests

composer install
vendor/bin/phpunit

No WordPress install, database or fixture site required — tests/bootstrap.php stands in for the seven WordPress and WooCommerce functions the plugin touches, recording what it was called with so the enqueue behaviour can be asserted. Runs on PHP 8.1+.

Tagged aai and ash_woocommerce_cookies, so --group aai targets it alongside other August Ash suites.

What the suite is actually protecting, since every one of these fails silently in production — caching quietly degrades with nothing in any log:

• the two blocked cookie names, and that the filter blocks only those two
• the STYXKEY_ prefix on the session cookie, which is what makes Varnish vary rather than bust
• DONOTCACHEPAGE pass-through, so cart/checkout/my-account stay uncacheable
• the hook wiring: accepted_args on the cookie filter, and enqueue priority above WooCommerce's
• JSON-escaping of the cart hash seeded into sessionStorage

assets/js/cookie-patch.js is not covered — the suite verifies the PHP half seeds the right state, not what the browser does with it.