DefinitelyTyped/express-graphql/express-graphql.d.ts

// Type definitions for express-graphql
// Project: https://www.npmjs.org/package/express-graphql
// Definitions by: Isman Usoh <https://github.com/isman-usoh>, Nitin Tutlani <https://github.com/nitintutlani>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped

/// <reference path="../express/express.d.ts" />

declare module "express-graphql" {
    import { Request, Response } from "express";

    /**
     * Used to configure the graphQLHTTP middleware by providing a schema
     * and other configuration options.
     */
    export type Options = ((req: Request) => OptionsObj) | OptionsObj
    export type OptionsObj = {
        /**
         * A GraphQL schema from graphql-js.
         */
        schema: Object,

        /**
         * An object to pass as the rootValue to the graphql() function.
         */
        rootValue?: Object,

        /**
         * A boolean to configure whether the output should be pretty-printed.
         */
        pretty?: boolean,

        /**
         * An optional function which will be used to format any errors produced by
         * fulfilling a GraphQL operation. If no function is provided, GraphQL's
         * default spec-compliant `formatError` function will be used.
         */
        formatError?: Function,

        /**
         * A boolean to optionally enable GraphiQL mode.
         */
        graphiql?: boolean,
    };

    type Middleware = (request: Request, response: Response) => void;

    /**
     * Middleware for express; takes an options object or function as input to
     * configure behavior, and returns an express middleware.
     */
    export default function graphqlHTTP(options: Options): Middleware;
}