index.js

const express = require('express');

const app = express();

const port = process.env.PORT || 5000;

const db = require('./db/db');

const router = require('./router.js');

const cors = require('cors');

//Configuro cors

let corsOptions = {
    origin: "*",
    methods: "GET,HEAD,PUT,PATCH,POST,DELETE",
    preflightContinue: false,
    optionsSuccessStatus: 204
};

//Middlewares

app.use(express.json());

app.use(cors(corsOptions));

app.use(router);

//Conexión a base de datos y levantar servidor

db.then(()=>{

    app.listen(port, ()=> {console.log("Servidor levantado en el puerto ", port)});

}).catch((err) => console.log(err.message));