This PR adds additional props to woocommerceanalytics events so we can filter based on how stores implement their cart & checkout pages.

New cart & checkout blocks are coming soon in the WooCommerce Blocks plugin. We're planning to evaluate these blocks by measuring conversion rates from the existing woocommerceanalytics events, in particular add_to_cart, product_checkout and product_purchase. To compare traditional and block-based UX, we need to add these new props to the events.

The new props are as follows. Values are 0 or 1, consistent with other boolean tracks props.

• cart_page_contains_cart_block
• cart_page_contains_cart_shortcode
• checkout_page_contains_checkout_block
• checkout_page_contains_checkout_shortcode

Changes proposed in this Pull Request:

• Utility functions for determining if a woo site is using shortcodes or blocks on the cart & checkout pages.
• Include this info as props on all woocommerceanalytics events.
• Cache this info in a transient (1-day life, jetpack-woocommerce-analytics-cart-checkout-info-cache).

Is this a new feature or does it add/remove features to an existing part of Jetpack?

This adds features to the existing woocommerce-analytics module.

Testing instructions:

• This requires WooCommerce to be installed and set up on the site, with some products. Recommend setting up Cash on delivery payment method for easy checkout.
• The events are disabled for development sites. Use an incognito window, or hack this by adding return true; at the start of Jetpack_WooCommerce_Analytics::shouldTrackStore().

• Open network tab in browser dev tools, search for pixel.wp.com.
• View a product on the front end of your site. You should see a request for woocommerceanalytics_product_view event. This should have new properties (parameters) as above. Check that the values are correct. You'll probably have 1 for shortcodes and 0 for blocks.

If you install the current master branch of WooCommerce Blocks, you can add the cart & checkout blocks to the cart & checkout pages and retest - the values should show the correct info. If don't have blocks plugin and want to hack some more, you can fake this by adding an html comment that looks like the start of one of the blocks.

You can also test edge cases such as:

• Add the shortcodes and blocks to the pages, i.e. use both at the same time.
• Delete all content from the pages, or switch in some alternative cart or checkout solution (e.g. One Page Checkout).
• Add cart/checkout shortcodes/blocks to other pages (not cart/checkout page).
• Break your woo setup or skip onboarding so there is no designated cart/checkout page.

Note that this is cached in a transient for a day, so if you change your setup, you'll need to wait a day to retest, or delete the transient:

yarn docker:wp transient delete "jetpack-woocommerce-analytics-cart-checkout-info-cache"

Note: right now, the events are not all consistently firing for block-based cart & checkout (e.g. woocommerce/woocommerce-blocks#2031). For example, product_checkout only works with shortcode checkout. This is a separate issue and will be fixed in a separate PR. Please be aware of this when testing with blocks :)

Proposed changelog entry for your changes:

• Added props to WooCommerce Analytics events indicating if store is using blocks or shortcodes on cart & checkout pages.