"Type ... doesn't have any fields"
Sometimes when working with union types you'll get the following error.
This is an example of a query that will result in such error:
This is because we allow querying union fields only in certain cases. GraphQL
__typename field but it's not present in GraphQL introspection
graphql-ppx doesn't know that this field exists. To fix your query
__typename. It's added behinds a scene as an implementation
detail and serves us as a way to decide which case to select when parsing your
This is an example of a correct query: