:default catch blocks with core.async and clojurescript

[cameron]

I'm having an issue where :default catch blocks are not working in clojurescript when in a go block.

The following code prints "a str" as expected:

(prn (try

           (throw "a str")

           (catch :default e e )))

The same code in a go block results in an unhandled exception 

(go (prn (try

                (throw "a str")

                (catch :default e e ))))

I can see an old core.async issue that added support for :default (http://dev.clojure.org/jira/browse/ASYNC-42) 

but no other references, is this a regression or something I'm missing?

I'm using clojurescript  "1.8.51"  and core.async "0.2.374"

Cameron.

[Kevin Downey]

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You will likely find that (throw (js/String. "a str")) will work the
same in both.

This issue has two parts:

1. String literals are somehow not objects or something in javascript (I
don't entirely understand this, but I vaguely recall that it is a thing)

2. The go macro uses js/Object as the exception type in the "catch all"
exception handler it creates to emulate exception handling.

You can verify that the combination of these two things causes this
problem by playing with this code:

(try (throw "foo") (catch js/Object e :good))

(try (throw (js/String. "foo")) (catch js/Object e :good))

(try (throw "foo") (catch :default e :good))

The "Fix" for the issue you linked didn't change "js/Object" to
":default" in the catch all, so it didn't actually fix anything.

--
And what is good, Phaedrus,
And what is not good—
Need we ask anyone to tell us these things?

[Kevin Downey]

I am not entirely sure what to do with this. What I did was re-open
async-42 with a link to this thread