JSFiddle - React, Tailwind, and code Playground

JavaScript

function Invoice() {
    this.read = function(callback_fun){
        var stmnt = "SELECT * FROM invoices ORDER BY ID DESC";
       // function callback(callback_fun){        
            var myrows = [];
            db.transaction(function(tx){
            tx.executeSql(stmnt, [], function(tx,result){
                debugger;
                for(var i = 0; i < result.rows.length; i++){
                    var row = result.rows.item(i);
                    myrows.push(row);
                }
                callback_fun(myrows);
                }, function(tx,error){
                   alert('Error: '+error.message);
                    return;
                });
            });
    };
};
var newInvoice = new Invoice();
var myResult;
newInvoice.read(function(r) {
    debugger;
    myResult = r;
});
setTimeout(function(){ alert(myResult); }, 6000);