Read from a csv file

I have a csv file uploaded in input type file and I want to read this file the exceljs but I don’t know how ? can you please help me with that. In the documentation it’s not mention how to read before prepossessing with exceljs this are the examples in the documentation :

// read from a file
var workbook = new Excel.Workbook();
workbook.csv.readFile(filename)
    .then(function(worksheet) {
        // use workbook or worksheet
    });
 
// read from a stream
var workbook = new Excel.Workbook();
workbook.csv.read(stream)
    .then(function(worksheet) {
        // use workbook or worksheet
    });
 
// pipe from stream
var workbook = new Excel.Workbook();
stream.pipe(workbook.csv.createInputStream());

This the begining of my code :

function ValidateFile(input) {
  
    var files = input.files || [];
    if (!files.length) return;
    var file = files[0];

    fileName = file.name;
    
   //what to do here ???

   var workbook = new Excel.Workbook();
   workbook.csv.read(stream)
    .then(function(worksheet) {
        
    });
}

Wich one can I use and how ? Thank you.

[1whatleytay]

This is really frustrating. Xlsx works really well in browser via the load method if you load an ArrayBuffer via FileReader, but load is inexplicably missing for CSVs. I can’t imagine why, a corresponding writeBuffer method exists, why not load??

The need to load a csv file is always present on browser, even if it is slower or less efficient. It makes absolutely no sense why CSV requires a node environment but Xlsx does not.

[Shiko1st]

Is there a chance to read csv and xlsx in browser?