import { type QueueOptions } from '@scratch/task-herder';
export declare const Headers: {
    new (init?: HeadersInit): Headers;
    prototype: Headers;
};
/**
 * Metadata header names.
 * The enum value is the name of the associated header.
 */
export declare enum RequestMetadata {
    /** The ID of the project associated with this request */
    ProjectId = "X-Project-ID",
    /** The ID of the project run associated with this request */
    RunId = "X-Run-ID"
}
export type ScratchFetchOptions = {
    /**
     * The name of the queue to use for this request.
     * If absent, the hostname of the requested URL will be used as the queue name.
     * This is a Scratch-specific extension to the standard RequestInit type.
     */
    queueName?: string;
    /**
     * The options to use when creating the queue for this request.
     * Ignored if a queue with the specified name already exists.
     */
    queueOptions?: QueueOptions;
};
/**
 * Check if there is any metadata to apply.
 * @returns {boolean} true if `metadata` has contents, or false if it is empty.
 */
export declare const hasMetadata: () => boolean;
/**
 * Non-destructively merge any metadata state (if any) with the provided options object (if any).
 * If there is metadata state but no options object is provided, make a new object.
 * If there is no metadata state, return the provided options parameter without modification.
 * If there is metadata and an options object is provided, modify a copy and return it.
 * Headers in the provided options object may override headers generated from metadata state.
 * @param {RequestInit} [options] The initial request options. May be null or undefined.
 * @returns {RequestInit|undefined} the provided options parameter without modification, or a new options object.
 */
export declare const applyMetadata: (options?: globalThis.RequestInit) => globalThis.RequestInit | undefined;
/**
 * Make a network request.
 * This is a wrapper for the global fetch method, adding some Scratch-specific functionality.
 * @param {RequestInfo|URL} resource The resource to fetch.
 * @param {RequestInit} [requestOptions] Optional object containing custom settings for this request.
 * @param {ScratchFetchOptions} [scratchOptions] Optional Scratch-specific settings for this request.
 * @see {@link https://developer.mozilla.org/docs/Web/API/fetch} for more about the fetch API.
 * @returns {Promise<Response>} A promise for the response to the request.
 */
export declare const scratchFetch: (resource: RequestInfo | URL, requestOptions?: globalThis.RequestInit, scratchOptions?: ScratchFetchOptions) => Promise<Response>;
/**
 * Create a new fetch queue with the given identifier and option overrides.
 * If a queue with that identifier already exists, it will be replaced.
 * Queues are automatically created as needed with default options, so
 * there's no need to call this unless you need to override the default queue options.
 * WARNING: If the old queue has is not empty, it may continue to run its tasks in the background.
 * If you need to cancel fetch tasks in that queue before replacing it, do so manually first.
 * @param queueName The name of the queue to create.
 * @param overrides Optional overrides for the default QueueOptions for this specific queue.
 */
export declare const createQueue: (queueName: string, overrides: Partial<QueueOptions>) => void;
/**
 * Set the value of a named request metadata item.
 * Setting the value to `null` or `undefined` will NOT remove the item.
 * Use `unsetMetadata` for that.
 * @param {RequestMetadata} name The name of the metadata item to set.
 * @param {any} value The value to set (will be converted to a string).
 */
export declare const setMetadata: (name: RequestMetadata, value: any) => void;
/**
 * Remove a named request metadata item.
 * @param {RequestMetadata} name The name of the metadata item to remove.
 */
export declare const unsetMetadata: (name: RequestMetadata) => void;
/**
 * Retrieve a named request metadata item.
 * Only for use in tests. At the time of writing, used in scratch-vm tests.
 * @param {RequestMetadata} name The name of the metadata item to retrieve.
 * @returns {string|null} The value of the metadata item, or `null` if it was not found.
 */
export declare const getMetadata: (name: RequestMetadata) => string | null;