wrap-exceptions does not throw Exceptions (if wrapped in try+)

[jwr]

I just discovered, much to my surprise, that my code that has a try+/catch block with a (catch Exception e...) at the end does not catch "403" exceptions thrown by wrap-exceptions. It does catch everything else, e.g. other exceptions, just not those thrown by wrap-exceptions.

This is at least unintuitive and I'm not quite sure what is the right way to go, but: I filed an issue with slingshot (scgilardi/slingshot#24) and now I'm thinking whether it is a good idea for a library such as clj-http to throw exceptions using throw+.

I think (I'm not 100% certain, though) that while using try+/throw+ within the library is fine, exceptions that do not get caught should follow the standard Java conventions. I did not expect to see throw+ in clj-http and I had to look at the source code to see it.

[dakrone]

I've played with this, so far it seems like a Slingshot issue, I'll talk to Steve and get to the bottom of it.

[dakrone]

I talked to Steve about this (see his comment on the slingshot issue). I think I would rather have a little bit of a disconnect (like having to do (catch Object o ...) or (catch map? m ...) in the try+) since it gives the benefit of being able to encapsulate the data in the response.

If you don't care about the contents of the exception, you could easily do a (catch Exception e ...) with a regular try, and if you do, I would recommend using (catch Object o ...).

Does this work for your usage?

[jwr]

Please take a look at my comments in the slingshot issue: scgilardi/slingshot#24 (comment)

Basically, I can't find anything wrong with what you're doing, it's just that I did not expect that changing try to try+ would start missing exceptions. It is the combination of slingshot unwrapping behavior and the fact that you are using throw+ that caused the issue.

I can see how it makes sense to throw maps with full information — so as for clj-http I'd just suggest that you change the documentation somewhat. Currently it says:

"clj-http will throw a Slingshot Stone that can be caught by a regular (catch Exception e ...) or in Slingshot's try+ block"

... which is true, but you can't expect both to work, e.g. (try+ (http/get...) (catch Exception e)) will not work.