Firebase increase badge count with iOS - firebase

Question

I'm developing an app with Firebase and I implemented push notifications right. And now I'm trying to show badge icon but I can't find a good information to do that. I read I should work on the server side and the example code is something like this.
"aps" :
{
"alert" : "Your notification message",
"badge" : badgecount ,
"sound" : "bingbong.aiff"
}
But I don't know where to add the code in my function.
This is how my function looks like:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.pushNotifications = functions.database.ref('/messages/{messageId}')
.onCreate(event => {
const data = event.data;
const fromId = data.fromId;
const toId = data.toId;
const message = data.message;
console.log(fromId + ' sent a message to' + toId);
return admin.database().ref('/users/' + fromId).once('value', snapshot => {
var user = snapshot.val();
var payload = {
notification: {
title: user.username,
body: message
}
}
admin.messaging().sendToDevice(user.fcmToken, payload)
.then(function(response) {
// See the MessagingDevicesResponse reference documentation for
// the contents of response.
console.log("Successfully sent message:", response);
})
.catch(function(error) {
console.log("Error sending message:", error);
});
})
Can someone give me an advice how to do this?

Answer 1

The "apns" object goes in the payload object as a sibling to notification:
var payload = {
notification: {
title: user.username,
body: message
},
apns: {
// badge and other ios only data here here
}
}
I would also suggest returning the admin.messaging() method: return admin.messagins().sendToDevice().ect. It might not be required, but Firebase suggests returning all thenable references.