feat(algolia): fix highlighting hit type

[francoischalifour]

This updates our requirements for highlighting a hit.

Description

We used to expect a hit to contain an objectID property because Algolia hits owns it. However, we also support highlighting for Recent Searches and facet hits, which aren't strictly Algolia hits, and therefore don't own an objectID property.

We now expect an _highlightResult for highlightHit and _snippetResult for snippetHit, which is more accurate.

Related

• feat(algolia): add getAlgoliaFacetHits preset #451 (comment)

[Haroenv]

You suggested Record<string, unknown> in message, any reason why you changed it to unknown again?

[francoischalifour]

Given:

import { HighlightResult } from '@algolia/client-search';

export type HighlightedHit<THit> = THit & {
  _highlightResult?: HighlightResult<THit>;
};

I tried HighlightResult<Record<string, unknown>> with a DocSearch hit and it doesn't work because properties can be null (e.g., content).

We need to improve the client's HighlightResult type to allow this.