Consider the following schema:

type Query {
  blogPageBySlug(slug: String!): BlogPage
  node(id: ID!): Node
}

type BlogPage implements Node {
  id: ID!
  title: String @semanticNonNull
}

interface Node {
  id: ID!
}

And the following query:

query somethingSomethingQuery
  @throwOnFieldError
  @raw_response_type {
  node(id: "test-id") {
    ... on BlogPage {
      title
    }
  }
  blogPageBySlug(slug: "test-slug") {
    title
  }
}

Those would currently generate this raw response type:

export type somethingSomethingQuery$rawResponse = {
  readonly blogPageBySlug: {
    readonly id: string;
    readonly title: string;
  } | null | undefined;
  readonly node: {
    readonly __typename: "BlogPage";
    readonly id: string;
    readonly title: string | null | undefined;
  } | {
    readonly __typename: string;
    readonly id: string;
  } | null | undefined;
};

It seems like the @throwOnFieldError isn't properly considered in the case of a type refinement on a field returning an abstract type, since the title is typed as nullable below the node field and non-null on the field directly returning the object type.

We use @raw_response_type a lot to write typed mocked data for component demos and tests, so this makes it a lot harder to write accurate mock data for our developers.