what is this error? SyntaxError: Unexpected end of JSON input

var https = require('https');

function printMessage(username, badges, points){
    const message = `${username} has ${badges} badges and ${points} points`;
    console.log(message);
}

function getProfile(username){
        var request = https.get(`https://wwwteamtreehouse.com/${username}.json`, response => {

                                var body = '';
                                response.on('data', data => {
                                    body += data.toString();        
                                })

                                response.on('end', () => {
                                    const profile = JSON.parse(body);
                                    printMessage(username, profile.badges.length, profile.points.JavaScript);
                                })      
                        });
            request.on('error', error => console.error(error));

}


const users = process.argv.slice(2);
users.forEach(getProfile);