pr-writer-ex-info does not print false values and tries to reimplement map printer

Question

While working on CLJS-1722 I spotted two issues with pr-writer-ex-info:

1) if data or cause happen to be "false", they are skipped in printing
2) the code tries to mimic map printer

This patch fixes both issues. It turns out printing real info map yields exactly same string output and plays better with cljs-devtools printer (which newly sees real map instead of soup of strings and values).

For reference: pr-writer-ex-info was implemented in CLJS-983

Answer 1

Comment made by: dnolen

Can you explain why you think 1 is a problem? data should be a map. cause should be an error but I suppose that could be a problem if you have a rethrow which wraps some throwable value (which of course could be anything).

Answer 2

Comment made by: darwin

Disclaimer: I don't have much experience with Clojure and almost none with Java.

Just by reading the code I didn't see any checks in ex-info (or in ExceptionInfo ctor) to restrict data or cause. So I assumed anything can be passed in and printer should print it as-is without additional logic. I assumed that checking for nil values was intentional abbreviation when CLJS-983 was implemented. And I assumed that false value was supposed to be printed. At least I personally would want it to be distinguished from nil. Or there should be no abbreviation at all.

Answer 3

Reference: https://clojure.atlassian.net/browse/CLJS-1723 (reported by darwin)