Improve error messages by using pr-str instead of str when printing objects

Question

Many error messages from ClojureScript include the invalid argument like this:

(throw (js/Error. (str "Doesn't support name: " x)))

If {{x}} is nil, then the error message produces is {{"Doesn't support name: "}} which is a bit mystifying to debug. If {{x}} was wrapped with {{pr-str}} then the error message would be the much more understandable: {{"Doesn't support name: nil"}}.

If there's interest in this, then I can prepare a patch which wraps these kinds of errors with pr-str.

Answer 1

Comment made by: dnolen

Go for it

Answer 2

Comment made by: mfikes

I also pondered this for a bit with CLJS-2089. Seems like the right thing to do in general.

Answer 3

Comment made by: mfikes

Patch no longer applies.

Answer 4

Comment made by: slipset

Should apply now, I hope

Answer 5

Comment made by: mfikes

0001-CLJS-1908-Wrap-vars-in-throw-message-with-pr-str.patch no longer applies

Answer 6

Comment made by: slipset

0001-CLJS-1908-Wrap-vars-in-throw-message-with-pr-str-2.patch updated, should apply

Answer 7

Comment made by: mfikes

0001-CLJS-1908-Wrap-vars-in-throw-message-with-pr-str-2.patch LGTM

Answer 8

Comment made by: mfikes

0001-CLJS-1908-Wrap-vars-in-throw-message-with-pr-str-2.patch passes CI and Canary (/)

Answer 9

Comment made by: mfikes

0001-CLJS-1908-Wrap-vars-in-throw-message-with-pr-str-2.patch added to Patch Tender (i)

Answer 10

Reference: https://clojure.atlassian.net/browse/CLJS-1908 (reported by desk@danielcompton.net)