increment safely in faunadb

gistfile1.txt

Update(
  Select(
    "ref", 
    Get(
      Match(
        Index("title_unique"),
        "TITLE HERE "
      )
    )
  ),
  { 
    data: { 
      users_ok: Add(
        Select(
          ['data', 'users_ok'], 
          Get(
            Match(
              Index("title_unique"),
              "TITLE HERE "
            )
          )
        ),
        1
      )
    }
  }
)