For non-seqable types, seq evals to object info when running tests

Observing on master and 1.9.946, and as far back as 1.7.28:

If you do this in a REPL and call (test-seq) you will get the second test form throwing as expected:

Note that this also behaves properly if you are in a REPL and put this code in a namespace and load it via require while in the REPL:

Have src/foo/core.cljs containing

and then try it at the REPL:

If instead you drop the code (apart from the require form) into the bottom of the cljs.core-test namespace (or, the top of cljs.primitives-test) and run script/test-simple or script/test-self-parity you will see some concerning output. Also note the odd true and false return values.

A simpler case is (prn (seq #js {:a 1 :b 2})) which will print

.