DefinitelyTyped/types/koa-graphql/index.d.ts

// Type definitions for koa-graphql 0.8
// Project: https://github.com/chentsulin/koa-graphql
// Definitions by: Matheus Gonçalves da Silva <https://github.com/PlayMa256>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
// TypeScript Version: 3.0
/// <reference types="node" />

import { Context, Request, Response, Middleware } from "koa";
import {
    GraphQLError,
    GraphQLSchema,
    GraphQLFieldResolver,
    ValidationContext,
    ASTVisitor
} from "graphql";
import { GraphQLParams, RequestInfo } from "express-graphql";

export type Options =
    | ((request: Request, repsonse: Response, ctx: Context) => OptionsResult)
    | OptionsResult;

export type OptionsResult = OptionsData | Promise<OptionsData>;

export interface OptionsData {
    /**
     * A GraphQL schema from graphql-js.
     */
    schema: GraphQLSchema;

    /**
     * A value to pass as the context to this middleware.
     */
    context?: any;

    /**
     * An object to pass as the rootvalue to the graphql() function.
     */
    rootValue?: any;

    /**
     * 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?: (error: GraphQLError, context?: any) => any;

    /**
     * An optional array of validation rules that will be applied on the document
     * in addition to those defined by the GraphQL spec.
     */
    validationRules?: Array<(arg0: ValidationContext) => ASTVisitor>;

    /**
     * An optional function for adding additional metadata to the GraphQL response
     * as a key-value object. The result will be added to "extensions" field in
     * the resulting JSON. This is often a useful place to add development time
     * info such as the runtime of a query or the amount of resources consumed.
     *
     * Information about the request is provided to be used.
     *
     * This function may be async.
     */
    extensions?: (info: RequestInfo) => { [key: string]: any };

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

    /**
     * A resolver function to use when one is not provided by the schema.
     * If not provided, the default field resolver is used (which looks for a
     * value or method on the source value with the field's name).
     */
    fieldResolver?: GraphQLFieldResolver<any, any>;
}

export default function graphqlHTTP(options: Options): Middleware;