export type FetchParams = [input: string | URL, init?: RequestInit];
export type JSONObject = {
    [key: string]: unknown;
};
export type BodyData = FormData | URLSearchParams | JSONObject;
type InterceptHandler<A> = (request: A, onComplete: Promise<void>) => Promise<A>;
export declare abstract class Interceptor<H extends InterceptHandler<Req>, Req = Parameters<H>[0]> {
    private callbacks;
    addHandler(...cb: H[]): void;
    protected chainHandlers<R extends Parameters<H>>(...request: R): Promise<Req>;
}
export type Callback = (request: FetchParams, onComplete: Promise<void>) => Promise<FetchParams>;
export type InterceptPredicate = (input: string | URL, init?: RequestInit) => boolean;
export declare class RequestInterceptor extends Interceptor<Callback> {
    private predicate;
    constructor(predicate: InterceptPredicate);
}
export declare function parseFetchRequestBody(init: RequestInit): BodyData;
export declare function makeFetchRequestBody(init: RequestInit, newBody: BodyData): string | FormData | URLSearchParams;
export declare function shopifyUrlStartsWith(url: URL | string, prefix: string): boolean;
export {};