Check duplicate value from an exsting array and push the uniqe value in js

 let userData = await User.findOne(user.id);

let deviceId = [];

// if the fbDeviceId is not present in the user table

if (!userData.fbDeviceId) {

deviceId.push(req.body.deviceId);

} else {

//then assign all the fetched fbDeviceId to deviceId array

deviceId = userData.fbDeviceId;

//check if the deviceid exist or not

let index = userData.fbDeviceId.indexOf(req.body.deviceId);

//if not exist then push the new value to the array

if (index === -1) {

deviceId.push(req.body.deviceId);

}

}

// console.log('new deviceId', deviceId)

await User.update({ id: userData.id }).set({ fbDeviceId: deviceId });