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

Fire events the same way the user does

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

function modifySelectionPerMouseMove(selectionRange, { document, target, node, offset }) {
    const selectionFocus = resolveCaretPosition({
        target,
        node,
        offset
    });
    if ('node' in selectionRange) {
        // When the mouse is dragged outside of an input/textarea,
        // the selection is extended to the beginning or end of the input
        // depending on pointer position.
        // TODO: extend selection according to pointer position
        /* istanbul ignore else */ if (selectionFocus.node === selectionRange.node) {
            const anchorOffset = selectionFocus.offset < selectionRange.start ? selectionRange.end : selectionRange.start;
            const focusOffset = selectionFocus.offset > selectionRange.end || selectionFocus.offset < selectionRange.start ? selectionFocus.offset : selectionRange.end;
            setUISelection(selectionRange.node, {
                anchorOffset,
                focusOffset
            });
        }
    } else {
        const range = selectionRange.cloneRange();
        const cmp = range.comparePoint(selectionFocus.node, selectionFocus.offset);
        if (cmp < 0) {
            range.setStart(selectionFocus.node, selectionFocus.offset);
        } else if (cmp > 0) {
            range.setEnd(selectionFocus.node, selectionFocus.offset);
        }
        const selection = document.getSelection();
        selection === null || selection === undefined ? undefined : selection.removeAllRanges();
        selection === null || selection === undefined ? undefined : selection.addRange(range.cloneRange());
    }
}

export { modifySelectionPerMouseMove };