Clojurians Log v2

hey folks, I can't understand the reason behind this line of code https://github.com/tonsky/datascript/blob/master/src/datascript/db.cljc#L733

can someone help me with it please ?

what is the reason behind that hashmap

I think that's a clojure precondition.

http://blog.fogus.me/2009/12/21/clojures-pre-and-post/

https://clojure.org/reference/special_forms#__code_fn_code_name_em_param_em_em_condition_map_em_em_expr_em

All it says is that, before you even try to do anything, make sure that (db? db) returns true. It checks to make sure that the right things are being passed (or returned) from the function.

interesting, didn't know about them