feat(medusa): Add metadata to StorePostCartsCartLineItemsItemReq

[erikengervall]

This is my first contribution.

I tried my best to follow the available documentation on how to contribute -- LMK if there's anything missing 🙏🏼

What - what changes are in this PR

This PR adds the Line Item metadata field to the StorePostCartsCartLineItemsItemReq request.

If omitted, no changes are applied.

Why - why are these changes relevant

I created a feature request very recently and figured I'd take a stab at creating a PR myself. Here's a quote of the particular use case:

We've got a use case where we'd like to enrich line items' metadata field just before entering the checkout flow. Without the addition of metadata to StorePostCartsCartLineItemsItemReq, the options I see are

• Creating a custom endpoint that's almost identical to StorePostCartsCartLineItemsItemReq but that accepts metadata
  • Although this would work just fine in the short term, we would effectively opt out of future updates to this endpoint, which I would prefer not to do.
• Call deleteItem followed by addItem as addItem accepts metadata.
  • This is quite hacky and it also causes the UI to render the Empty Cart page for a brief moment.

How - how have the changes been implemented

Not sure what this refers to.

The changes were developed locally and pushed to a new branch on my fork.

Testing - how has the changes been tested or how can the reviewer test the feature

Two additional unit tests have been created to cover this particular functionality.

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🦋 Changeset detected

Latest commit: bf56127

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@medusajs/medusa	Patch
@medusajs/client-types	Patch

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Name	Status	Preview	Comments	Updated (UTC)
medusa-docs	🔄 Building (Inspect)			Jun 28, 2023 6:21am

[olivermrbl]

Thanks for the contribution @erikengervall. I have a minor suggestion. Let me know what you think :)

[olivermrbl]

todo: I believe we can do validated.metadata || {} and let our dedicated update metadata util take care of this. The new and existing metadata will be merged correctly in the LineItemService.update method.

Would be good with a test to verify

[erikengervall]

Merging sounds even better 👍🏼

Feel free to make the change, if not I’ll have a look tomorrow (it’s late here) 🙂

[olivermrbl]

All good - I'll push the changes so we can include it in today's release :)

[olivermrbl]

But otherwise LGTM, feel free to merge as you please :)