...
resolve: (root, params) => {
  var user = User.findOne({email: params.data.email}).exec()
  return user;
}
...

{
  "data": {
"login": "{ _id: 596f4cc4f51fa12bf0f5a001,n  updatedAt: 2017-07-19T12:12:52.736Z,n  createdAt: 2017-07-19T12:12:52.736Z,n  email: 'myemail@gmail.com',n  password: '$2a$12$bhPG4TPGR6by/UBTeAnzq.lyxhfMAJnBymDbkFDIHWl5.XF2JG62O',n  __v: 0 }"