server.js

const express = require("express");
const mongoose = require("mongoose");
const ShortUrl = require('./models/shortUrl');
const app = express();

mongoose.connect('mongodb://localhost/urlShortener', {
    useNewUrlParser: true,
    useUnifiedTopology: true
}); 

app.set("view engine", "ejs");
app.use(express.urlencoded({extended: true}));

app.get("/", async (req, res) => {
    const shortUrls = await ShortUrl.find();
    res.render("index", {shortUrls: shortUrls})
})

app.post("/shortUrls", async (req, res)=>{
    await ShortUrl.create({full: req.body.fullUrl});
    res.redirect("/");
})

app.get("/:shortUrl", async (req, res) => {
    const shortUrl = await ShortUrl.findOne({ short: req.params.shortUrl});
    if(!shortUrl)
        return res.sendStatus(404);

    shortUrl.clicks++;
    shortUrl.save();

    res.redirect(shortUrl.full);

})

app.listen(process.env.PORT || 5000, console.log("server started"));