Inline Fragments aren't exported

I was led to this plugin due to an issue I had over at gatsby-plugin-graphql-codegen. The author recommended I try this plugin to see if it solved it, and it didn’t, so I figured I’d open an issue here as well.

There’s more context on the other issue, but generally the inline fragments that are generated on subtypes of an interface aren’t exported, leading to a need to duplicate those types.

//
// the inline fragments below generate useful types that aren't exported
//
export const WidgetFragment = graphql`
  fragment WidgetFragment on Widget {
    widgetId
    widgetType
    ... on ImageListWidget {
      images {
        ...ImageFragment
      }
    }
    ... on ImageWidget {
      image {
        ...ImageFragment
      }
    }
  }
`;

//
// these types aren't exported, so cannot be used as WidgetProps
//
type WidgetFragment_ImageSliderWidget_Fragment = (
  Pick<ImageSliderWidget, 'widgetId' | 'widgetType'>
  & { images: Array<Maybe<ImageFragmentFragment>> }
);

type WidgetFragment_ImageWidget_Fragment = (
  Pick<ImageWidget, 'widgetId' | 'widgetType'>
  & { image: Maybe<ImageFragmentFragment> }
);

//
// only this type is exported
//
export type WidgetFragmentFragment = WidgetFragment_ImageSliderWidget_Fragment | WidgetFragment_ImageWidget_Fragment;

[johnrom]

Looks like the missing config setting is below. I wonder if this can be configured outside of your plugin in a config file? I’m not sure if codegen.yml can be inherited by CLI configuration. Let me know if there’s some way to override the configuration or if you’re willing to export these types in the default configuration, in which case I can open a PR.

I confirmed making this change in node_modules/gatsby-plugin-typegen/workers/codegen.js does what I need.

@graphql-codegen/typescript-operations: config.exportFragmentSpreadSubTypes

[johnrom]

Yes, in the example I gave in the initial descriptions, you can see the exact prop types for <ImageWidget /> and <ImageSliderWidget /> are created but not exposed. This is for spread subtype fragments. I could maybe go with a union type as a workaround if those fragments are exported (haven’t tried), but it doesn’t make that much sense since these types inherit from a common interface.