import type { FastifyInstance } from 'fastify';
import type { IncomingHttpHeaders } from 'http';
import { DocumentNode, GraphQLError } from 'graphql';
import type { TypedDocumentNode } from '@graphql-typed-document-node/core';
export type GQLResponse<T> = {
    data: T;
    errors?: GraphQLError[];
};
export type QueryOptions<TVariables extends Record<string, unknown> | undefined = undefined> = {
    operationName?: string | null;
    headers?: IncomingHttpHeaders;
    cookies?: Record<string, string>;
    variables?: TVariables;
};
export declare function createMercuriusTestClient(
/**
 * Fastify instance, in which it should have been already registered `mercurius`.
 */
app: FastifyInstance, 
/**
 * Global Options for the client, including:
 * - headers
 * - url
 * - cookies
 */
opts?: {
    /**
     * Global Headers added to every query in this test client.
     */
    headers?: IncomingHttpHeaders;
    /**
     * GraphQL Endpoint registered on the Fastify instance.
     * By default is `/graphql`
     */
    url?: string;
    /**
     * Global Cookies added to every query in this test client.
     */
    cookies?: Record<string, string>;
}): {
    /**
     * Query function.
     *
     * @param query Query to be sent. It can be a DocumentNode or string.
     * @param queryOptions Query specific options, including:
     * - variables
     * - operationName
     * - headers
     * - cookies
     */
    query: <TData extends Record<string, unknown> = Record<string, any>, TVariables extends Record<string, unknown> | undefined = undefined>(query: TypedDocumentNode<TData, TVariables> | DocumentNode | string, queryOptions?: QueryOptions<TVariables>) => Promise<GQLResponse<TData>>;
    /**
     * Mutation function.
     *
     * @param mutation Mutation to be sent. It can be a DocumentNode or string.
     * @param mutationOptions Query specific options, including:
     * - variables
     * - operationName
     * - headers
     * - cookies
     */
    mutate: <TData extends Record<string, unknown> = Record<string, any>, TVariables extends Record<string, unknown> | undefined = undefined>(mutation: TypedDocumentNode<TData, TVariables> | DocumentNode | string, mutationOptions?: QueryOptions<TVariables>) => Promise<GQLResponse<TData>>;
    /**
     * Returns federated entity by provided typename and keys
     * @param options
     * @returns Promise with requested _Entity
     */
    getFederatedEntity: <TData extends Record<string, unknown> = Record<string, any>>(options: {
        typename: string;
        keys: Record<string, string | number>;
        typeQuery: string;
    }) => Promise<TData>;
    /**
     * Set new global headers to this test client instance.
     * @param newHeaders new Global headers to be set for the test client.
     */
    setHeaders: (newHeaders: IncomingHttpHeaders) => void;
    /**
     * Set new global cookies to this test client instance.
     * @param newCookies new Global headers to be set for the test client.
     */
    setCookies: (newCookies: Record<string, string>) => void;
    /**
     * Send a batch of queries, make sure to enable `allowBatchedQueries`.
     *
     * https://github.com/mercurius-js/mercurius#batched-queries
     *
     *
     * @param queries Queries to be sent in batch.
     * @param queryOptions Cookies | headers to be set.
     */
    batchQueries: (queries: {
        query: DocumentNode | string;
        variables?: Record<string, any>;
        operationName?: string;
    }[], queryOptions?: Pick<QueryOptions, 'cookies' | 'headers'>) => Promise<GQLResponse<any>[]>;
    /**
     * Global headers added to every request in this test client.
     */
    headers: IncomingHttpHeaders;
    /**
     * Global cookies added to every request in this test client.
     */
    cookies: Record<string, string>;
    /**
     * GraphQL Subscription
     */
    subscribe: <TData extends Record<string, unknown> = Record<string, any>, TVariables extends Record<string, unknown> | undefined = undefined>(opts: {
        /**
         * Subscription query, can be a DocumentNode or string
         */
        query: string | DocumentNode | TypedDocumentNode<TData, TVariables>;
        /**
         * Initial payload, usually for authorization
         */
        initPayload?: (() => Record<string, any> | Promise<Record<string, any>>) | Record<string, any>;
        /**
         * Subscription data function
         */
        onData(response: GQLResponse<TData>): void;
        /**
         * Subscription specific headers
         */
        headers?: IncomingHttpHeaders;
        /**
         * Subscription specific cookies
         */
        cookies?: Record<string, string>;
        /**
         * query operationName
         */
        operationName?: string | null;
        /**
         * subscription variables
         */
        variables?: TVariables;
    }) => Promise<{
        unsubscribe: () => void;
    }>;
};