import { NetworkProtocol } from './types';
type RuleResult = {
    success: true;
} | {
    success: false;
    reason: string;
};
export interface NetworkRule {
    test: (url: URL) => RuleResult;
}
interface HostnameRuleConfig {
    allowLocalhost: boolean;
}
export declare class HostnameRule implements NetworkRule {
    private readonly allowLocalhost;
    constructor(config: HostnameRuleConfig);
    test(url: URL): RuleResult;
}
export declare class ProtocolRule implements NetworkRule {
    private protocols;
    constructor(protocols: NetworkProtocol[]);
    test(url: URL): RuleResult;
}
export declare function isLocalhost(hostname: string): boolean;
export {};