I have a grid with numbers representing a type of error
the number is translated into a string e.g. 0 => No Error

When I do an excel export, I have numbers in the sheet
But when I do a CSV export I have strings

How can I have strings in my excel exports?

Sample here: https://plnkr.co/edit/LG7wMcPPp9cT7mGl?open=main.js&preview

let gridApi;

const gridOptions = {
  columnDefs: [
    {
      headerName: "Error Type",
      field: "a",
      valueFormatter: errorFormatter
    }
  ],
  rowData: createRowData(),
  enableRangeSelection: true,
  enableFillHandle: true,
};

function errorFormatter(params) {
  if(params.value == null)
    return "";

  switch (params.value){
    case 0:
      return "No Error";
    case 1:
      return "Reading Error";
    case 2:
      return "Parsing Error";
  }
}

function createRowData() {
  const rowData = [];

  for (let i = 0; i < 100; i++) {
    rowData.push({
      a: Math.floor(Math.random() * 2)
    });
  }

  return rowData;
}

// setup the grid after the page has finished loading
document.addEventListener("DOMContentLoaded", function () {
  const gridDiv = document.querySelector("#myGrid");
  gridApi = agGrid.createGrid(gridDiv, gridOptions);
});