Add ShippingOption override to cart

[alecritson]

This PR looks to add the ability to carts for developers to override a shipping option for a cart in a single request, useful if you want to estimate what the total cost a cart will have with a certain shipping option selection, to present to the end user.

Usage

You can get an estimated shipping option for the cart like so:

$cart->getEstimatedShipping([
    'postcode' => '123456',
    'state' => 'Essex',
    'country' => Country::first(),
]);

This will fetch the cheapest shipping option from the manifest, but by default will not set the shipping override, so pipelines will function as they currently do. In order for the pipelines to take the override into account you just pass the additional setOverride parameter:

$cart->getEstimatedShipping([
    'postcode' => '123456',
    'state' => 'Essex',
    'country' => Country::first(),
], setOverride: true);

Now when you call calculate() on a cart, the override will be taken into account, bypassing any shipping address logic you may have in place.

This is a "once" off effect so, say you have another request that calls calculate() without setting the meta above, the pipeline will not take it into account.

If you use the CartSession facade, this can remember the meta for you in the session, making subsequent calls easier:

CartSession::estimateShippingUsing([
    'postcode' => '123456',
    'state' => 'Essex',
    'country' => Country::first(),
]);

You may not need to provide all arguments, but may affect how shipping options are resolved and which are added to the manifest.

Once set though, you can pass the optional estimateShipping parameter when getting the current cart.

This will use the shipping override in the pipelines, based on the

CartSession::current(estimateShipping: true);

Behind the scenes, we're just using the getEstimatedShipping on the cart as we fetch it and setting the override before the calculate() method is called.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
lunar-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 30, 2023 9:50am

[glennjacobs]

Nice. I think it just needs some docs adding.

[glennjacobs]

Can we change this to an H2 in the docs so the shipping header shows on the right?

### Adding shipping/billing address

[glennjacobs]

I just spotted this was added. I presume it's for orders that are being collected and not delivered.

Can we add the usage to the docs? Maybe also at the same time give an example of how you can manually override the shipping option directly on the cart too?