/**
 * @internal Only for the use of DevXp
 * Util to get a free port to run tests on.
 */
export declare function findPortInRange(host: string, startPort: number, endPort?: number): Promise<number | undefined>;
/**
 * @internal Only for the use of DevXp
 * Util to check if a port is used or not
 */
export declare function isUsed(host: string, port: number): Promise<boolean>;
/**
 * @internal Only for the use of DevXp
 * Util to write code that depends on a port being unused. Tries to run
 * the specified code on a specified port and retries with next port (<= options.endPort)
 * if it fails due to the port being bound already.
 * @param run code to run that depends on a port being unused.
 * @param startPort port that should be used for the first try.
 * @param options further options.
 * @returns
 */
export declare function runOnUnusedPort<T>(run: (port: number) => Promise<T>, startPort: number, options?: {
    range?: number | number[];
    /**
     * Part of error message that indicates that the
     * port is already in use.
     * @default 'EADDRINUSE'
     */
    errorMessage?: string;
    /**
     * Error message that should be displayed if no
     * free port was found in the specified range.
     */
    displayMessage?: string;
    /**
     * Callback that is executed every time the code failed
     * due to the port being used. Can be used to do info logs.
     */
    onUsedCallback?: (port: number) => void;
}): Promise<T>;