Edit in JSFiddle

currentDisplay = ""
$("#search").on("keyup change", (ev)->
                query = $(ev.target).val()
                return if query.length < 3
                setTimeout( ()=>
                               return if query != $(ev.target).val()
                               return if currentDisplay == query
                               currentDisplay = query
                               queryMovie(query).then(updateMovies)
                           , 300)
                )