How do I execute a node js file on MacOS? - node.js

Question

I've started the tutorial for Node.JS on tutorialspoint, but I can't get past the first step: https://www.tutorialspoint.com/nodejs/nodejs_first_application.htm
I us MacOS 10.13.5
I've created the following js file, named main.js.
var http = require("http");
http.createServer(function (request, response) {
// Send the HTTP header
// HTTP Status: 200 : OK
// Content Type: text/plain
response.writeHead(200, {'Content-Type': 'text/plain'});
// Send the response body as "Hello World"
response.end('Hello World\n');
}).listen(8081);
// Console will print the message
console.log('Server running at http://127.0.0.1:8081/');
It's a copy-paste of the tutorial, but when I try to run the given command node main.js nothing happens.
When I write the code directly in the node CLI I get the following response:
Server {
domain:
Domain {
domain: null,
_events: { error: [Function: debugDomainError] },
_eventsCount: 1,
_maxListeners: undefined,
members: [] },
_events:
{ request: [Function],
connection: [Function: connectionListener] },
_eventsCount: 2,
_maxListeners: undefined,
_connections: 0,
_handle:
TCP {
reading: false,
owner: [Circular],
onread: null,
onconnection: [Function: onconnection],
writeQueueSize: 0 },
_usingSlaves: false,
_slaves: [],
_unref: false,
allowHalfOpen: true,
pauseOnConnect: false,
httpAllowHalfOpen: false,
timeout: 120000,
keepAliveTimeout: 5000,
_pendingResponseData: 0,
maxHeadersCount: null,
_connectionKey: '6::::8081',
[Symbol(asyncId)]: 192 }
Edit:
The first time I tried writing it in the command line I misspelled response. I fixed it now and now I get the above response.
Edit 2
Here's what happens in the terminal. I included ls so you can see that it contains the file I'm trying to call

Answer 1

After running ps -a | grep node I saw I already had a process running. After I killed it I was able to execute my file.