`conditionalByType` ignores part of the result when validation is missing

[ntvangoor]

Is there an existing issue for this?

• I have searched the existing issues

Code of Conduct

• I agree to follow this project's Code of Conduct

Code Sandbox link

No response

Bug report

conditionalByType ignores part of the result in a specific scenario.
When one type (e.g. 'heroSection') has its own parser, but another (e.g. 'block') does not, then the result for the latter is ignored during parsing.
This happens because conditionalParser returns an empty object in this case.

This does not work:

conditionalByType({
  block: { // result is { _type: 'block' }
    children: true,
    style: true,
    listItem: true,
    markDefs: true,
    level: true,
  },
  heroSection: (heroSection) => ({
    title: true,
    description: true,
    photos: heroSection.field("photos[]").project((photo) => ({
      src: photo.field("image").field("asset").deref().field("url"),
      alt: true,
      caption: true,
    })),
    columns,
  })
})

But this does:

conditionalByType({
  block: { // result is { _type: 'block', children: ..., style: ..., etc... }
    children: true,
    style: q.string(),
    listItem: true,
    markDefs: true,
    level: true,
  },
  heroSection: (heroSection) => ({
    title: true,
    description: true,
    photos: heroSection.field("photos[]").project((photo) => ({
      src: photo.field("image").field("asset").deref().field("url"),
      alt: true,
      caption: true,
    })),
    columns,
  })
})

[devinatbryt]

@ntvangoor I've found a silly little hack around this. You could create a fragment like so:

const baseSectionFragment = q.fragment<{ _type: string }>().project((block) => ({
  _type: block.field("_type", z.string()),
}));

conditionalByType({
  block: { // result is { _type: 'block', children: ..., style: ..., etc... }
    ...baseSectionFragment,
    children: true,
    style: q.string(),
    listItem: true,
    markDefs: true,
    level: true,
  },
  heroSection: (heroSection) => ({
    ...baseSectionFragment,
    title: true,
    description: true,
    photos: heroSection.field("photos[]").project((photo) => ({
      src: photo.field("image").field("asset").deref().field("url"),
      alt: true,
      caption: true,
    })),
    columns,
  })
})

While this doesn't fix the underlying issue, it does allow you to ensure every block has something it needs to validate that way the "conditionalByType" doesn't skip it if it doesn't have any validation.