解决exceljs导出的xlsx文件中合并单元格部分边框样式不显示问题

//设置合并数据
function setMerge(luckyMerge, worksheet) {
  const mergearr = Object.values(luckyMerge);
  mergearr.forEach(function (elem) {
    const startCell = `${createCol(elem.c)}${elem.r + 1}`
    const endCell = `${createCol(elem.c + elem.cs - 1)}${elem.r + elem.rs}`
    const end_border = worksheet.getCell(`${endCell}`).border
    const start_border = worksheet.getCell(`${startCell}`).border
    const border = {}
    if (start_border) {
      border.top = start_border.top
      border.left = start_border.left
    }
    if (end_border) {
      border.bottom = end_border.bottom
      border.right = end_border.right
    }
    worksheet.mergeCells(`${startCell}:${endCell}`);
    worksheet.getCell(`${startCell}:${endCell}`).border = border
  });
}

需要对合并后的单元格再做边框处理，分别取开始单元格的上边框和左边框，结束单元格的右边框和下边框