How to use

differenceBy

function

in

LoDashStatic

// Remove user to this role and link him to authenticated.
  _.differenceBy(role.users, body.users, role._id ? '_id' : 'id')
   .filter(user => user.role !== `${root._id || root.id}`.toString())
   .forEach(user => {
    arrayOfPromises.push(this.updateUserRole(user, authenticated._id || authenticated.id));
   });

// Add user to this role.
  _.differenceBy(body.users, role.users, role._id ? '_id' : 'id')
   .filter(user => user.role !== `${root._id || root.id}`.toString())
   .forEach(user => {
    arrayOfPromises.push(this.updateUserRole(user, roleID));
   });