This PR does three things to improve the UI when the cart is being updated in composite checkout:
Temporary line items (items not yet verified on the server and for which we have no title or price data) now are hidden in the order review list (previously they had been shown as ‘…’).
The “Continue” buttons for each step now display “Updating cart…” when the cart is updating. Previously they had displayed “Please wait…” (which they still display if some other activity is pending).
The submit button now displays “Please wait…” when the form is not in a ready state (including when the cart is being updated but also when validating the contact form). Previously the button was just disabled in those other states except for when the form was submitting. (It would be nice to change this to “Updating cart” as well, but that’s much more complicated because that’s a calypso-specific state currently and the payment methods are not inside calypso so we’ll wait on that for a future update.)
Add a domain to your cart for an account that has no plan.
Visit composite checkout and verify that you see the upsell in the sidebar.
Verify that clicking the “Add to Cart” button causes the “Continue” button to display “Updating cart” and the submit button to display “Please wait”.
Verify that the number of items in the review step does not change until the cart finishes updating at which point you should see the plan included in the list.
Unfortunately, no screenshots were provided by the developer.