Problem/Motivation
When creating a view that uses the Search API, if that index supports multiple bundles or entity types, the custom union for results is never defined.
Steps to reproduce
Create a Search API Index for nodes
Create 2 content types
Create a view, GraphQL view, search api, entity display
Proposed resolution
Modify `getGraphQlUnionTypes` and introduce `hasGraphQlUnionTypes` to check for a custom union.
Add a resolver for that union type.
Remaining tasks
Nil
User interface changes
Nil
API changes
`getGraphQlUnionTypes` will now only return types for a custom union. Eg MySearchResultRow, and not return a generic such as NodeUnion
Data model changes
Previous behaviour was to return the first union type if only one existed.
This is observed to cause issues with spilling incorrect __typename entities out of the search index, and assigning an incorrect entity type.
A Search API based view's results field will now always return a union, and throw an error if non-supported content types are in the result-set.
Upgrading?
If you had a previous Search API view that returned only one content type, eg result: [NodePage!]!, it'll now be within a union.
Example:
query MyQuery {
mySearchApiView {
results {
... on NodePage {
id
title
}
}
}