@testing-library/user-event/dist/types/event/selection/modifySelection.d.ts

Fire events the same way the user does

/**
 * Extend/shrink the selection like with Shift+Arrows or Shift+Mouse
 */
export declare function modifySelection({ focusNode, focusOffset, }: {
    focusNode: Node;
    /** DOM Offset */
    focusOffset: number;
}): void;