// codegen.ts
import type { CodegenConfig } from "@graphql-codegen/cli";

const config: CodegenConfig = {
  schema: "./schema.ts",
  ignoreNoDocuments: true,
  generates: {
    "./schema-generated.ts": {
      plugins: ["typescript", "grafast"],
      config: {
        overridesFile: "./schema-manual-types.ts",
      },
    },
  },
};

export default config;

// schema.ts
import { get } from "grafast";
import { typedMakeGrafastSchema } from "./schema-generated.js";

const schema = typedMakeGrafastSchema({
  typeDefs: /* GraphQL */ `
    type Query {
      character(id: Int!): Character
    }

    interface Character {
      id: Int!
      name: String!
    }
  `,
  objects: {
    Character: {
      plans: {
        name($character) {
          return get($character, "name");
        },
      },
    },
    // ...
  },
  unions: {
    // ...
  },
  interfaces: {
    // ...
  },
  inputObjects: {
    // ...
  },
  scalars: {
    // ...
  },
  enums: {
    // ...
  },
});

// schema-manual-types.ts
import type { Maybe, Step } from "grafast";
import type { CharacterData } from "./data.js";

// IMPORTANT: Steps must represent the nullable version (suitable for returning
// from a plan resolver). Should you wish to specify a different (non-nullable)
// version that's suitable as a field plan resolver's first argument, use the
// `source:` key in addition to specifying `nullable:`.
export type Overrides = {
  Character: {
    nullable: Step<Maybe<CharacterData>>;
  };
};