Node - exceljs: writing to file breaks fomulas in the file - node.js

Question

I have an excel (xlsx) file that contains random columns. Some of these columns have formulas mapped to the sum of some cells; for example:
=J8+F9-H9
In my case I have the following three columns:
F: number
H: number
J: =sum of previous row's F and H cell's values.
I aim to get external data and store them cell by cell in this workbook. For this I am using Node module exceljs.
This is my code so far, I am harcoding values for now (which I will be getting from another file later on).
var workbook = new Excel.Workbook();
var filename = 'Bank Synoptic Journal.xlsx'
workbook
.xlsx
.readFile(filename)
.then(function() {
var worksheet = workbook.getWorksheet('Bank Synoptic');
var row = null;
row = worksheet.getRow(8);
row.getCell('J').value = Math.random();
row.commit();
for(var i=9; i<=305;i++) { //row
row = worksheet.getRow(i);
row.getCell('F').value = Math.random();
row.getCell('H').value = Math.random();
row.commit();
}
})
.then(function() {
return workbook.xlsx.writeFile(filename + '_modified.xlsx');
})
.then(function() {
console.log('Done!');
});
It prints the output into a new excel file. The problem I am facing is that for cells 'J' ie which contains the formulas; these cells are breaking with no consitency:
Some cells keep formulas and do the calculations
Others have no more formulas nor calculations done (have '0' instead of formula)
Recalculations are not done automatically using this injection mechanism
(Snapshots)
What I am missing or doing wrong that is leading to this error?

Answer 1

After several trials and errors I moved to Apache POI and so built the script using Java.
I downloaded and included the following JARs in my project:
It manipulates rows/columns and keeps the formulas intact. Once you open the modified excel file all you have to do is refresh (On Windows: ctrl + alt + f9) and it will recalculate.