How To Use jQuery To Post A CSV File To A Node.js Server

front-end.js

// using jQuery
$("#2020data").submit(function(e) {

  $.ajax({
    url: "https://e0d92634.ngrok.io/test",
    type: "POST",
    data: new FormData(this),
    processData: false,
    contentType: false
  });

  return false;
});

index.html

<form id="2020data">
  <input type="file" name="csvFile">
  <button type="submit" class="btn btn-default">Upload CSV File</button>
</form>

server-side.js

const express = require('express');
const multer = require('multer');

const app = express();
const upload = multer();

app.post('/test', upload.single('csvFile'), async (req, res) => {
  try {
    const csvFile = req.file.buffer.toString();
    const rows = csvFile.split('\n');

    for (let row of rows) {
      const columns = row.replace(/"/g, '').split(',');
      console.log(columns);
    }

    res.sendStatus(200);
  } catch (err) {
    console.log(err);
    res.sendStatus(400);
  }
});

app.listen(3000, function() {
  console.log(`Server started at ${new Date().toString()}`);
});

A bit of a walkthrough here https://golightlyplus.com/use-jquery-post-csv-file-node-js-server/