feat(core): filter out child cart line items

[jorgemoya]

What/Why?

Filter out child cart items (items with parentEntityId) from cart and cart analytics to prevent duplicate line items when products have parent-child relationships, such as product bundles.

Simplified this implementation over #2726 because it's not easy to know which CartSelectedMultipleChoiceOption from the product options/modifiers has attached this child product to the parent item, so we would get duplicate information (in the product options list, shown below, as well as a separate product item below the parent product). I opted for less duplication and code simplicity.

Testing

Migration steps

Step 1: GraphQL Fragment Updates

The parentEntityId field has been added to both physical and digital cart item fragments to identify child items.

Update core/app/[locale]/(default)/cart/page-data.ts:

  export const PhysicalItemFragment = graphql(`
    fragment PhysicalItemFragment on CartPhysicalItem {
      entityId
      quantity
      productEntityId
      variantEntityId
+     parentEntityId
      listPrice {
        currencyCode
        value
      }
    }
  `);

  export const DigitalItemFragment = graphql(`
    fragment DigitalItemFragment on CartDigitalItem {
      entityId
      quantity
      productEntityId
      variantEntityId
+     parentEntityId
      listPrice {
        currencyCode
        value
      }
    }
  `);

Step 2: Cart Display Filtering

Cart line items are now filtered to exclude child items when displaying the cart.

Update core/app/[locale]/(default)/cart/page.tsx:

  const lineItems = [
    ...cart.lineItems.giftCertificates,
    ...cart.lineItems.physicalItems,
    ...cart.lineItems.digitalItems,
- ];
+ ].filter((item) => !('parentEntityId' in item) || !item.parentEntityId);

Step 3: Analytics Data Filtering

Analytics data collection now only includes top-level items to prevent duplicate tracking.

Update core/app/[locale]/(default)/cart/page.tsx in the getAnalyticsData function:

- const lineItems = [...cart.lineItems.physicalItems, ...cart.lineItems.digitalItems];
+ const lineItems = [...cart.lineItems.physicalItems, ...cart.lineItems.digitalItems].filter(
+   (item) => !item.parentEntityId, // Only include top-level items
+ );

Step 4: Styling Update

Cart subtitle text color has been updated for improved contrast.

Update core/vibes/soul/sections/cart/client.tsx:

-                  <span className="text-[var(--cart-subtext-text,hsl(var(--contrast-300)))] contrast-more:text-[var(--cart-subtitle-text,hsl(var(--contrast-500)))]">
+                  <span className="text-[var(--cart-subtext-text,hsl(var(--contrast-400)))] contrast-more:text-[var(--cart-subtitle-text,hsl(var(--contrast-500)))]">
                     {lineItem.subtitle}
                   </span>

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🦋 Changeset detected

Latest commit: 48a5426

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

This PR includes changesets to release 1 package

Name	Type
@bigcommerce/catalyst-core	Patch

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Project	Deployment	Review	Updated (UTC)
catalyst	Ready	Preview, Comment	Jan 20, 2026 9:14pm

[jorgemoya]

@andrewreifman Let me know what you think about this. I kind of took #2726 and simplified it. More info on the PR description. I updated the contrast of the product subtitled as requested.

[andrewreifman]

@andrewreifman Let me know what you think about this. I kind of took #2726 and simplified it. More info on the PR description. I updated the contrast of the product subtitled as requested.

I think this definitely looks better than the previous PR. Looking at all that info displayed, I'm not loving the labels and values all being displayed together, but I think for the sake of this PR we can leave it as is. I still want to rethink/redesign the cart so we can make more changes to it in the future.