how to send json data under passport local strategy - node.js

Question

This is my passport Login Handler.
Now I want to send JSON Data under every condition so that API can access the response and on behalf of this display anything on frontend.
//Login Handler
passport.use('local-user', new LocalStrategy(
function(username, password, done) {
User.getUserByUsername(username, function(err, user){
if(err) {
console.log('error')
logger.log('error', 'Error Generates on User.getUserByUsername Query on users.js file');
throw err;
}
if(!user){
//res.send('unknown user');
console.log('Unknown User');
return done(null, false, {message: 'Unknown User'});
}
User.comparePassword(password, user.password, function(err, isMatch){
if(err) {
logger.log('error', 'Error Generates on User.comparePassword Query on users.js file');
throw err;
}
if(isMatch){
return done(null, user);
}else{
return done(null, false, {message: 'Invalid Credential, please check carefully...!'})
}
});
});
}
));
Anyone have any idea for this? Thanks in advance

Answer 1

The local strategy will pass the user or error with done(), then you receive that with a callback and pack it with res.json()
Here is my implementation. May help?
passport.use(
new LocalStrategy(
{
usernameField: "email"
},
function(username, password, done) {
User.findOne({ email: username }, function(err, user) {
if (err) {
return done(err);
}
if (!user) {
return done(null, false, {
email: "Email not found"
});
}
if (!user.validPassword(password)) {
return done(null, false, {
password: "Password is wrong"
});
}
return done(null, user);
});
}
)
);
router.post("/login", function(req, res) {
passport.authenticate("local", function(err, user, info) {
if (err) {
res.status(404).json(err);
return;
}
if (user) {
const token = user.generateJwt();
res.status(200);
res.json({
userInfo: user,
token: token
});
} else {
res.status(401).json(info);
}
})(req, res);
});