Untitled

var ModuleOne = require('./moduleone');
var ModuleTwo = require('./moduletwo');

function dataQuery() {

    this.query = function(text, callback) {
        //...//
    }
};

module.exports = dataQuery;

var dataQuery = require('./dataquery.js');

function query() {

    var dq = new dataQuery();
    dq.query('interesting data', function(json){
        console.log("query response: " + json);
    });
}

query();

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Data Query</title>
    <script src="dataquery-bundle.js" type="text/javascript"></script>
</head>
<body>
<script src="dataapp.js" type="text/javascript"></script>
</body>
</html>