feat(checkout): CHECKOUT-8516 Add Shipping Discount to Cart Page

[valentindellangela]

What?

We are working on a new feature to allow shipping discount to be created on the promotion side and applied to a cart with a selected shipping option.

This ticket is about showing the discount on the cart page and will be composed of 2 tickets:

• a BCApp ticket to return the discounted_shipping_cost (https://github.com/bigcommerce/bigcommerce/pull/60385)
• a Cornerstone ticket to update the template using this new variable

This feature is protected behind a LaunchDarkly Experiment and will be slowly ramped up when the feature development is complete.

Tickets / Documentation

• https://bigcommercecloud.atlassian.net/browse/CHECKOUT-8516

Screenshots (if appropriate)

Tested using Stencil CLI:

Without Shipping Discount:

With Shipping Discount:

ping @bigcommerce/team-checkout

[valentindellangela]

Seems to be failing on each PRs 🤷‍♂️

[valentindellangela]

Hi @bigcommerce/team-themes

Are you please able to:

• review my PR
• let me know if there is a way to confirm it won't break any functional tests - I don't expect any but I don't know how to double-check
• help me release it if everything looks safe

Thanks!

[bc-yevhenii-buliuk]

@valentindellangela LGTM, but add please the CHANGELOG.md file with the appropriate changes

[valentindellangela]

@bc-yevhenii-buliuk Thanks, I've updated the CHANGELOG.md.
I suppose the flow is to merge this anytime and then at some point the theme team will create a release?

[bc-yevhenii-buliuk]

@bc-yevhenii-buliuk Thanks, I've updated the CHANGELOG.md. I suppose the flow is to merge this anytime and then at some point the theme team will create a release?

@valentindellangela right now, our team is busy with the release process, so your PR can be merged after the release. I added the label do not merge temporarily until we finalize the release.