How to clean nodejs response after every user request? - node.js

Question

Every time a user enter to our URL he get the response of the last user + his new response.
I'm new with nodejs and I think I don't understand the way this server works :)
Anyway, here you can see the app:
https://s1-nodejs.herokuapp.com (You will need to reload the page to see the duplicate response every time you reload).
And this is the code I deployed to Heroku:
const start = Date.now();
// using the http module
var http = require('http');
var https = require('https');
var request = require('request');
var domain;
var apiKey = 'example';
var domainResultJson = [];
var promises = [];
// look for PORT environment variable,
// else look for CLI argument,
// else use hard coded value for port 8080
port = process.env.PORT || process.argv[2] || 8080;
// create a simple server
let server = http.createServer(function (req, res) {
for (var i = 0 ; i < 10 ; i++ ) {
var domain = 'example-'+i+'.com';
promises.push(CheckIfDomainAvailable(https,domain,apiKey,domainResultJson));
}
Promise.all(promises).then(function(values) {
//console.log(values);
res.statusCode = 200;
res.setHeader('Content-Type', 'text/plain');
for (var i in values) {
val = values[i];
res.write(val);
}
res.end();
}).catch(
console.error
);
function CheckIfDomainAvailable(https,domain,apiKey,domainResultJson) {
return new Promise(function (success, failure) {
request('https://example.com/api/v1?'
+ 'apiKey=' + apiKey + '&d=' + domain + '', function (error, response, body) {
if (!error && response.statusCode == 200) {
domainResultJson.push('1');
success(body);
} else {
failure(error);
}
});
});
}
});
// listen on the port
server.listen(port, function () {
console.log('app up on port: ' + port);
});

Answer 1

Try to declare let promises = []; inside function (req, res) { ... }, like this:
// ...
let server = http.createServer(function (req, res) {
let promises = []; // <= Define promises container here.
for (var i = 0 ; i < 10 ; i++ ) {
var domain = 'example-'+i+'.com';
promises.push(CheckIfDomainAvailable(https,domain,apiKey,domainResultJson));
}
// ...