[REPL Window] undefined namespace when starting a shadow-cljs cljs REPL Window

[PEZ]

This is using the preview of the coming Calva with that spiffy REPL Window:

Opening a ClojureScript REPL in a shadow-cljs project (Calva itself as it happens) the prompt displays:

undefined=>

I don't have the time right now to investigate it further, not even if the namespace really is undefined 😄, so just dumping the bug report here.

[cfehse]

This is fixed in version 2.0.49.

[cfehse]

This was not fixed in version 2.0.49!

The root cause for the problem is that the cljs repl is connected but no application is connected. In this situation the code:

let res = this.session.eval("nil");
await res.value;

The returned promise contains literally nothing and the resulting res.ns is undefined.

I tested this issue with the calva cljs-lib - and I have no idea how to "connect an application to the REPL" for that project.

[PEZ]

You press F5 😄

It's mentioned here: https://github.com/BetterThanTomorrow/calva/wiki/How-to-Contribute

[PEZ]

It is not much we can do about ”no prompt when no app”, but we could, maybe, detect the situation. I have tried many times, and failed. That is not to say it is not possible. I had a chat with Thomas Heller about this some months ago, and he mentioned a message bus that shadow-cljs has, that could probably be used to make Calva know what state the connection is in.

[cfehse]

You press F5 😄

That's a problem: you cannot run the debug instance in the directory you are debugging from - at least not on Windows. So I made a copy of calva and ran the debugged calva there. This will not start the clsj-lib. At least not for me.

[cfehse]

It is not much we can do about ”no prompt when no app”, but we could, maybe, detect the situation. I have tried many times, and failed. That is not to say it is not possible. I had a chat with Thomas Heller about this some months ago, and he mentioned a message bus that shadow-cljs has, that could probably be used to make Calva know what state the connection is in.

Unfortunately shadow-cljs simply returns nothing instead of an error.