I'm populating an existing Excel file using ExcelJS.

Setting the value directly, without re-adding the dataValidation wipes out the dropdown. It's necessary to re-add the validations again using the code below (for example):

const workbook = new ExcelJS.Workbook();
await workbook.xlsx.load(buffer);
const targetSheet = workbook.worksheets[1];
let row = targetSheet.getRow(rowNumber); // Target row
cell = row.getCell(4); // Target cell
cell.dataValidation = {
      type: 'list',
      allowBlank: false,
      formulae: ['"Option1,Option2,Option3"']
};

Now, I also need to read the existing dropdown values before setting the new value but using cell.dataValidation does not work to read the current dataValidation, but strangely it works to write them.

How to read the existing dataValidation of a specific cell using ExcelJS?