Added clicks abd ability to redirect to full url

You can click on short or full url.
Increments the count and updates in db.
Sends 404 if null url.

server.js

@@ -22,7 +22,7 @@ const ShortUrl = require("./models/shortUrl");
 
 //get
 // index page with request and response parameters
-// show all url in index page
+// show all url from table "ShortUrl" in index page
 app.get("/", async (req, res) => {
   const shortUrls = await ShortUrl.find();
   res.render("index", { shortUrls: shortUrls });
@@ -33,6 +33,25 @@ app.post("/shortUrls", async (req, res) => {
   ShortUrl.create({ full: req.body.fullUrl });
   res.redirect("/");
 });
+
+//for clicking on short url after slash
+//parameter ":shortUrl"
+app.get("/:shortUrl", async (req, res) => {
+  //find the one where in "short", a "shortUrl" is found
+  const shortUrl = await ShortUrl.findOne({ short: req.params.shortUrl });
+
+  //if user sends empty shorturl,send 404
+  if (shortUrl == null) return res.sendStatus(404);
+
+  //otherwise increase the click
+  shortUrl.clicks++;
+  //save the changes in table
+  shortUrl.save();
+
+  //redirect the full link corresponding the short url we found
+  res.redirect(shortUrl.full);
+});
+
 // start listening on specified port 4567
 //can set as environment var
 app.listen(process.env.PORT || 4567);