MongoDB Fetch check if data exists - node.js

Question

I am trying to find the best way to write this code. I fetch locations from a remote resource and need to check if there are any new locations present in the data, if there are I should add them to my database, if they are not new I just want to update them.
const http = require('http');
const timeout = 5000; //5 seconds
const MongoClient = require('mongodb').MongoClient;
// Database Name
const dbName = 'weatherApp';
const url = 'mongodb://localhost:27017';
// Connect using MongoClient
MongoClient.connect(url, function(err, client) {
if(err){
console.log(err);
return;
}
const locationsCollection = client.db(dbName).collection('locations');
(function fetchTemperatureLoop(){
console.log('Started http request..');
http.get('remote url..', function(resp){
var data = '';
resp.on('data', (chunk) => {
data += chunk;
});
resp.on('end', () => {
if(data.isJson()){
var locations = JSON.parse(data).toArray();
(function locationsLoop(){
var location = locations.pop();
locationsCollection.findOne({location: location.location}, function(err, result){
if(err){
console.log(err);
return;
}
if(result){
//Exists
var measurements = result.measurements;
measurements.push({timestamp: +new Date, temperature: location.temperature})
locationsCollection.update({location: location.location}, {$set: {measurements: measurements}}, function(err){
if(err){
console.log(err);
return;
}
console.log('Added new temperature for location: ' + location.location);
continueLocationsLoop();
});
}else{
//Doesnt exist
location.measurements = [];
location.measurements.push({timestamp: +new Date, temperature: location.temperature});
locationsCollection.insert(location, function(err){
if(err){
console.log(err);
return;
}
console.log('Created new location: ' + location.location);
continueLocationsLoop();
});
}
});
function continueLocationsLoop(){
if(locations.length){
locationsLoop()
}else{
setTimeout(fetchTemperatureLoop, timeout);
}
}
})();
}
});
}).on("error", (err) => {
console.log("Error: " + err.message);
console.log("Continue anyways..");
setTimeout(fetchTemperatureLoop, timeout);
});
})();
});
String.prototype.isJson = function(){
try{
JSON.parse(this);
}catch(e){
return false;
}
return true;
}
Object.prototype.toArray = function(){
var arr = [];
for(var key in this){
if(this.hasOwnProperty(key)){
arr.push(this[key]);
}
}
return arr;
}
I really want to avoid using so many closures but I dont want to repeat myself either. Any help rewriting this code in an optimal way is much appriciated.
My main problem was illiterating through the locations and doing the calls to the database.