Why index.html is rendered in Node.js

I have a handler for '/', which redirects to /login.html. However, even though i'm explicitly calling to redirection, the page that is rendered is STILL index.html.

it's pretty lame behaviour, since I'm expecting A and gets B. How can I solve it?

var app = express();

app.use(express.static('public'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: false}));
app.use(cookieParser());
app.use(session({ secret: 'keyboard cat', resave: false, saveUninitialized: false }));
app.use(passport.initialize());
app.use(passport.session());

MW:

app.use('/', (req, res, next) => {
    if (req.user) {
        next();
    } else {
        res.redirect('/login');
    }
});

app.post('/login',
  passport.authenticate('local', {
      successRedirect: '/index.html',
      failureRedirect: '/login.html'
  })
);

via Chen