Allow :npm-deps to be specified per-build or per-target

[aiba]

I have a project that has both a browser frontend and also a react-native frontend, and they share clojurescript code and a single deps.edn file and a single shadow-cljs.edn file. But they need to have separate node_modules directories.

I'd like to be able to specify different :npm-deps for different targets, e.g.:

 :target-defaults
 {:browser {:js-options {:js-package-dirs ["web/node_modules"]
                          :npm-deps {:install-dir "web"}}}
  :react-native {:js-options {:js-package-dirs ["mobile/node_modules"]
                              :npm-deps {:install-dir "mobile"}}}}

But it seems that :npm-deps is only accepted at the top level of the config.

[thheller]

Currently, this is tricky since the :npm-deps install runs once when shadow-cljs first starts. This is far before any actual builds are looked at or started. See #998

Most likely I will be removing the automatic install of :npm-deps entirely at some point. It has been nothing but a nuisance and has lots of quirks. Instead it'll probably become manual command, which you could then pass a directory to I guess.

So, something like npx shadow-cljs install-npm-deps --dir mobile or so.

Would that be a suitable fix? I mean its not impossible to look at build configs and running the install multiple times, I'm just skeptical of the automatic install given the problems it has.

[aiba]

Yes, that would work great for my use case. If it's not too much trouble, it would also be handy to get a message or warning when running watch or compile, indicating that it may be necessary to re-run install-npm-deps command.