Posting as a followup from a conversation on the Clojurians Slack.
The following shows that find is not implemented for ClojureScript on transient maps:
cljs.user=> (def m (transient {}))
#'cljs.user/m
cljs.user=> (def m (assoc! m :a 1))
#'cljs.user/m
cljs.user=> (find m :a)
nil
Alex Miller believes that this was addressed in Clojure in https://clojure.atlassian.net/projects/CLJ/issues/CLJ-700
That ticket addresses contains? on transient hash-maps, which is likely similar, but this function already works in ClojureScript:
cljs.user=> (contains? m :a)
true
Note that (get m :a) also works.
