[BUG] Template data validation lost

🐛 Bug Report

I have a template Excel file which includes data validations. When I use exceljs to write data to the template the data validations are lost.

Lib version: 3.8.2

Steps To Reproduce

// index.js
const Excel = require("exceljs");
(async () => {
  const workbook = new Excel.Workbook();
  await workbook.xlsx.readFile("./template.xlsx"); // Has data validation
  await workbook.xlsx.writeFile("./output.xlsx"); // Data validation lost
})();

See attached sample project: exceljs-bug.zip

The expected behaviour:

Data validation is retained.

[Siemienik]

So todo list:

1. fix xlsx parser and renderer classes to be consistent with: [MS-XLSX]-120411.pdf
2. typings to current existed Worksheet.dataValidations https://github.com/exceljs/exceljs/blob/master/index.d.ts#L955
3. add dataValidation getter and setter for Column
4. add dataValidation getter and setter for Row
5. add posibility to set dataValidation by Range
6. typings to all above
7. update documentation

[florianLucas]

Hi,

Any news about this issue?