graphql-geojson.js

import { GraphQLScalarType } from "graphql";
import { Kind } from "graphql/language";

const typeDefs = /* GraphQL */ `
  scalar Coordinates
  scalar ObjectType

  interface Geometry {
    type: String!
    coordinates: Coordinates
  }

  interface GeoJSON {
    type: String!
  }

  type Point implements GeoJSON & Geometry {
    type: String!
    coordinates: Coordinates
  }

  type MultiPoint implements GeoJSON & Geometry {
    type: String!
    coordinates: Coordinates
  }

  type LineString implements GeoJSON & Geometry {
    type: String!
    coordinates: Coordinates
  }

  type MultiLineString implements GeoJSON & Geometry {
    type: String!
    coordinates: Coordinates
  }

  type Polygon implements GeoJSON & Geometry {
    type: String!
    coordinates: Coordinates
  }

  type MultiPolygon implements GeoJSON & Geometry {
    type: String!
    coordinates: Coordinates
  }

  type GeometryCollection implements GeoJSON {
    type: String!
    geometries: [Geometry]!
  }

  type Feature implements GeoJSON {
    id: String
    type: String!
    geometry: Geometry
    properties: ObjectType
  }

  type FeatureCollection implements GeoJSON {
    type: String!
    features: [Feature]
  }

  input GeometryInput {
    type: String!
    coordinates: Coordinates!
  }

  input FeatureInput {
    id: String
    type: String!
    geometry: GeometryInput
    properties: ObjectType
  }

  input FeatureCollectionInput {
    type: String!
    features: [FeatureInput]
  }
`;

const resolvers = {
  Coordinates: new GraphQLScalarType({
    name: "Coordinates",
    description: "A set of coordinates. x, y",
    parseValue(value) {
      return value;
    },
    serialize(value) {
      return value;
    },
    parseLiteral(ast) {
      return ast.value;
    }
  }),
  ObjectType: new GraphQLScalarType({
    name: "ObjectType",
    description: "Arbitrary JSON value",
    serialize: value => value,
    parseValue: value => value,
    parseLiteral: ast => {
      if (ast.kind !== Kind.OBJECT) {
        throw new GraphQLError(
          `Query error: Can only parse object but got a: ${ast.kind}`,
          [ast]
        );
      }
      return ast.value;
    }
  }),
  GeoJSON: {
    __resolveType: (obj, context, info) => obj.type
  },
  Geometry: {
    __resolveType: (obj, context, info) => obj.type
  }
};

export default {
  typeDefs,
  resolvers
};