Problem with reader literals and tools.namespace

[mmower]

Hi Jake.

So a problem has popped up that appears to be related to the use of tools.namespace for reloading (I'm reporting some detective work by llasram in #clojure here):

Ok, so usually namespaces are created on-demand and never removed
When clojure.core is first loaded and initialized data-readers, it creates
namespaces and vars for all the referenced reader functions, which will
be at that point unbound
Normally, when you then load a namespace, if the namespace object
already exists, it just creates/updates the bindings for vars in the namespace
But the tools.namespace reload code is destroying the namespace itself,
and creating a new one to then load code into
The data-readers map is left holding a var in a namespace object which
no-one else can see, and never gets new code loaded into it

The net result is that if you try and use a reader literal in your test code you get an exception, see: https://www.refheap.com/85727 which you don't get in normal use or from the REPL.

Any thoughts?

m/

[jakemcc]

Will have to look into it. Seems like either might need to do something different with tools.namespace or try to figure out if tools.namespace can be patched.

[jakemcc]

This is hacky and not actually a solution but you may be able to stop a specific namespace from being reloaded.

https://github.com/clojure/tools.namespace#managing-reloads

I haven't tried this but it seems like you may be able to do what it suggests to force certain namespaces to not be reloaded.

[mmower]

Hi Jake. I'm not sure how I'd apply this workaround as the namespace I'd need to stop reloading contains the namespace I'm testing which is, I assume, what is getting reloaded for each test run?