export type PartialResizeObserverEntry = Pick<ResizeObserverEntry, 'target'> & Partial<Omit<ResizeObserverEntry, 'target'>>;
/**
 * Mock-implementation of `ResizeObserver` with ability of simulating resize programmatically.
 * Useful for unit testing.
 */
export declare class ResizeObserverMock implements ResizeObserver {
    /** Callback. */
    protected readonly callback: ResizeObserverCallback;
    /** Observed elements. */
    protected readonly elements: Set<Element>;
    constructor(callback: ResizeObserverCallback);
    /** @inheritdoc */
    observe(target: Element): void;
    /** @inheritdoc */
    unobserve(target: Element): void;
    /** @inheritdoc */
    disconnect(): void;
    /**
     * Calls callback with given entries.
     * Each entry can omit all fields except `target`.
     * @param entries Entries.
     */
    simulateResize(entries: PartialResizeObserverEntry[]): void;
}