`typeahead`'s async `:data-source` is racey

[p-himik]

Consider this :data-source:

(fn [s callback]
  (go
    (<! (timeout (* 1000 (- 3 (count s)))))
    (callback (suggestions-for-search s)))
  nil)

Now when you start typing, type goo but slowly - 250-500 ms between key strokes.

You'll see the suggestions first opening for goo, then for go, then for g, even though the text input still contains goo.