testdb.js

const BlacklistIDModel = require('./models/blacklistidmodel');
const config = require('./config.json')
const mongoose = require('mongoose');
const fs = require('fs');
var configids = config.blacklistedids; 
var blacklistedids = []

mongoose.connect('mongodb://' + config.db.user + ':' + config.db.pass + '@' +'localhost/nogiveaway', function (err) {
    if (err) throw err;
    BlacklistIDModel.find({}, function(err, data){
        if(err){
          console.log(err);
        };
        if(data.length == 0) {
            console.log("nothing gotten")
        }
        for(var i=0;i<data.length;i++){
            if(data[i].userid.length == 1){
                blacklistedids.push(parseFloat(data[i].userid.toString()));
            }
            else{
                blacklistedids = blacklistedids.concat(data[i].userid);
            }
        }
        saveblacklist()

      });
}, {useNewUrlParser: true});

function saveblacklist(){
    blacklistedids.concat(configids)
    blacklistedids = [...new Set(blacklistedids)];
    fs.writeFile("outputx.json", JSON.stringify({blacklistedids:blacklistedids},null, 4), 'utf8', function (err) {
        if (err) {
            console.log("An error occured while writing JSON Object to File.");
            return console.log(err);
        }
        console.log("JSON file has been saved.");
    });
}