Express checkout, StoreAPI add-to-cart, and booking product compatibility

[annemirasol]

In #3865, we switched booking products back to the non-StoreAPI add-to-cart method for express checkout, as a quick fix to resolve an issue about missing data.

We need to investigate how to move it back to StoreAPI, and pass the missing data.

The issue seems to be that Bookings assumes that the data is in $_POST when an item is added to the cart, and it performs some validation code: https://github.com/woocommerce/woocommerce-bookings/blob/cd978fe375354dd5c5a872b96d27d6ff7c146cb8/includes/class-wc-booking-cart-manager.php#L88

This is the stack trace for when that part of the code is run, and we are using StoreAPI to add items to the cart:

[11-Feb-2025 17:56:10 UTC] #0 /var/www/html/wp-content/plugins/woocommerce-bookings/includes/class-wc-booking-cart-manager.php(371): wc_bookings_get_posted_data(Array, Object(WC_Product_Booking))
#1 /var/www/html/wp-includes/class-wp-hook.php(326): WC_Booking_Cart_Manager->add_cart_item_data(Array, 59)
#2 /var/www/html/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array)
#3 /var/www/html/wp-content/plugins/woocommerce/src/StoreApi/Utilities/CartController.php(1217): apply_filters('woocommerce_add...', Array, 59, 0, NULL)
#4 /var/www/html/wp-content/plugins/woocommerce/src/StoreApi/Utilities/CartController.php(105): Automattic\WooCommerce\StoreApi\Utilities\CartController->filter_request_data(Array)
#5 /var/www/html/wp-content/plugins/woocommerce/src/StoreApi/Routes/V1/CartAddItem.php(127): Automattic\WooCommerce\StoreApi\Utilities\CartController->add_to_cart(Array)
#6 /var/www/html/wp-content/plugins/woocommerce/src/StoreApi/Routes/V1/AbstractRoute.php(119): Automattic\WooCommerce\StoreApi\Routes\V1\CartAddItem->get_route_post_response(Object(WP_REST_Request))
#7 /var/www/html/wp-content/plugins/woocommerce/src/StoreApi/Routes/V1/AbstractCartRoute.php(125): Automattic\WooCommerce\StoreApi\Routes\V1\AbstractRoute->get_response_by_request_method(Object(WP_REST_Request))
#8 /var/www/html/wp-includes/rest-api/class-wp-rest-server.php(1292): Automattic\WooCommerce\StoreApi\Routes\V1\AbstractCartRoute->get_response(Object(WP_REST_Request))
#9 /var/www/html/wp-includes/rest-api/class-wp-rest-server.php(1125): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '/wc/store/v1/ca...', Array, NULL)
#10 /var/www/html/wp-includes/rest-api/class-wp-rest-server.php(439): WP_REST_Server->dispatch(Object(WP_REST_Request))
#11 /var/www/html/wp-includes/rest-api.php(449): WP_REST_Server->serve_request('/wc/store/v1/ca...')
#12 /var/www/html/wp-includes/class-wp-hook.php(324): rest_api_loaded(Object(WP))
#13 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#14 /var/www/html/wp-includes/plugin.php(565): WP_Hook->do_action(Array)
#15 /var/www/html/wp-includes/class-wp.php(418): do_action_ref_array('parse_request', Array)
#16 /var/www/html/wp-includes/class-wp.php(813): WP->parse_request('')
#17 /var/www/html/wp-includes/functions.php(1336): WP->main('')
#18 /var/www/html/wp-blog-header.php(16): wp()
#19 /var/www/html/index.php(17): require('/var/www/html/w...')
#20 {main}