Is there a straightforward way to use these in mutations? I have tried converting them straight to input types with graphql-compose but it seems to have some problems with the Union type in the CRS field. Additionally / alternatively, could you make the CRS field optional? It is optional in the spec.

Please include the style property, as described here: http://wiki.openstreetmap.org/wiki/Geojson_CSS

When I attempt to do this:

import {
    GeometryInterface
} from 'graphql-geojson'

I get the following error:

error TS7016: Could not find a declaration file │
for module 'graphql-geojson'. '/path/to/node_modules/graphql-geojson/i│
ndex.js' implicitly has an 'any' type.

The same issue arises irrespective of whether I import GeometryInterface or PointObject or any of the other exported elements.

This error

Could not find possible implementing types for GeoJSONGeometryInterface in schema. Check that schema.types is defined and is an array of all possible types in the schema.

will appear if you just have FeatureObject in your fields. You can easily reproduce this if you use your own demo https://github.com/ghengeveld/graphql-geojson-demo and change the code.

You have to change the file src/schema.js and set your schema to:

export default new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'Query',
    fields: () => ({
      feature: {
        type: FeatureObject,
        resolve: () => feature,
      },
    }),
  }),
})

If you now try to query and just want to get back the feature you will get the error I have copied above.