@testing-library/user-event/dist/esm/event/selection/modifySelection.js

Fire events the same way the user does

import { setUISelection } from '../../document/UI.js';
import '../../utils/dataTransfer/Clipboard.js';
import { getTargetTypeAndSelection } from './getTargetTypeAndSelection.js';

/**
 * Extend/shrink the selection like with Shift+Arrows or Shift+Mouse
 */ function modifySelection({ focusNode, focusOffset }) {
    var _focusNode_ownerDocument_getSelection, _focusNode_ownerDocument;
    const typeAndSelection = getTargetTypeAndSelection(focusNode);
    if (typeAndSelection.type === 'input') {
        return setUISelection(focusNode, {
            anchorOffset: typeAndSelection.selection.anchorOffset,
            focusOffset
        }, 'modify');
    }
    (_focusNode_ownerDocument = focusNode.ownerDocument) === null || _focusNode_ownerDocument === undefined ? undefined : (_focusNode_ownerDocument_getSelection = _focusNode_ownerDocument.getSelection()) === null || _focusNode_ownerDocument_getSelection === undefined ? undefined : _focusNode_ownerDocument_getSelection.extend(focusNode, focusOffset);
}

export { modifySelection };