Flash message is showing "1" it doesn't show any flash message - node.js

Question

I have a different problem in flash messages, and that is whenever i open my login page with flash message it's show a number "1". I don't know what does it mean.
app.js
const express = require('express')
const mongoose = require('mongoose')
const session = require('express-session')
const expressValidator = require('express-validator')
const MongoStore = require('connect-mongo')(session)
const path = require('path')
const passport = require('passport')
const bodyParser = require('body-parser')
const flash = require('connect-flash')
const routes = require('./routes/index')
const errorHandlers = require('./handlers/errorHandlers')
require('./handlers/passport')
const app = express();
app.use(express.static(path.join(__dirname + '/public')))
app.set('views', path.join(__dirname, 'public'))
app.engine('html', require('ejs').renderFile)
app.set('view engine', 'ejs')
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(expressValidator());
// populates req.cookies with any cookies that came along with the request
//app.use(cookieParser());
app.use(session({
secret: process.env.SECRET,
key: process.env.KEY,
resave: false,
saveUninitialized: false,
store: new MongoStore({ mongooseConnection: mongoose.connection })
}));
app.use(passport.initialize());
app.use(passport.session());
app.use(flash());
app.use((req, res, next) => {
res.locals.msg = req.flash();
res.locals.user = req.user || null;
res.locals.currentPath = req.path;
next();
});
// After allllll that above middleware, we finally handle our own routes!
app.use('/', routes);
// If that above routes didnt work, we 404 them and forward to error handler
app.use(errorHandlers.notFound);
// One of our error handlers will see if these errors are just validation errors
//app.use(errorHandlers.flashValidationErrors);
// done! we export it so we can start the site in start.js
module.exports = app;
userController.js
const mongoose = require('mongoose')
const User = mongoose.model('User')
const promisify = require('es6-promisify')
const { check } = require('express-validator/check')
exports.loginForm = (req, res) => {
res.render('login',{
msg: req.flash('error','welcome in login page')})
;
};
exports.registerForm = (req, res) => {
res.render('signup')
};
exports.aboutUs = (req, res) => {
res.render('about', { title: 'Register' })
};
exports.dash = (req, res) => {
res.render('dashhome', { title: 'Register' })
}
exports.homePage = (req, res) => {
res.render('index')
}
exports.contactForm = (req, res) => {
res.render('contact')
}}
login.ejs
This is my main syntax of ejs for flash message
<% if (msg) { %>
<%=msg %>
<% } %>
I expect the result is 'welcome in login page' but i don't know how i get this output when i open login page and see this result "1" instead of flash message.

Answer 1

You should assign data to req.flash before handling the response then you can pass the instance of the assigned data when rendering the view.
exports.loginForm = (req, res) => {
req.flash('error', 'welcome in login page');
res.render('login',{
msg: req.flash('error')
})
};

Answer 2

Before render the view, You just have to save the local messages using the flash like as below:
request.flash("error","Error Occured");
response.locals.messages = request.flash();
res.render('login',{
msg: req.flash('error')
})
Once you set the local messages, you are able to fetch it. Here messages is the main object which as a key called error. So, at the view you may access it like:
<% if (locals.messages) { %>
<script language="javascript">
alert("<%= messages.error %>");
</script>
<% } %>
You can perform whatever you want under the if condition.