JSFiddle - React, Tailwind, and code Playground

JavaScript

var  bufferString = "fname, lname, uid, phone, address\nJohn, Doe, 1, 444-555-6666, 34 dead rd\nJane, Doe, 2, 555-444-7777, 24 dead rd\nJimmy, James, 3, 111-222-3333, 60 alive way";

    var arr = bufferString.split('\n');     

    var jsonObj = [];
    var headers = arr[0].split(',');
    for(var i = 1; i < arr.length; i++) {
      var data = arr[i].split(',');
      var obj = {};
      for(var j = 0; j < data.length; j++) {
         obj[headers[j].trim()] = data[j].trim();
      }
      jsonObj.push(obj);
    }
    alert(JSON.stringify(jsonObj));