In this exercise, we’ll take a look at the endpoints to log in a user.

In order to log in a user we first need a POST request that takes in user credentials. We can add passport middleware in order to process the authentication and, if successful, serialize the user for us:

app.post("/login",
  passport.authenticate("insertStrategyHere", { failureRedirect : "/insertPathHere"}),
  (req, res) => {
    res.redirect("profile");
  }
);

We’re passing in passport.authenticate() as middleware. Using this middleware allows Passport.js to take care of the authentication process behind the scenes and creates a user session for us.

passport.authenticate() takes in:

• A string specifying which strategy to employ. In this case, we should use a local strategy.
• An optional object as the second argument. In this case, we should set the failureRedirect key to "/login". This will redirect the user to the /login page if the login process fails.

Once implemented, we can update the "/profile" endpoint to make use of the serialized user found in the request object, req.user:

app.get("/profile", (req, res) => {
  res.render("insertDashboardNameHere", { user: req.user });
}); 

This will render our profile view page along with the user data stored in the session!