shadow-cljs CLI utility should use lein if available

[thheller]

If lein and project.clj are available it should use lein classpath and use that instead of constructing its own from package.json.

Need to check if boot can export a classpath.

[shaunlebron]

Boot classpath with:

boot show -c

[thheller]

Thanks, first glance seems weird. I get a few entries like

/Users/zilence/.boot/cache/tmp/Users/zilence/745/d0ofpk/
/Users/zilence/.boot/cache/tmp/Users/zilence/745/11lgcg/
/Users/zilence/.boot/cache/tmp/Users/zilence/745/-p9hf6h/

These seem to be different on the next invocation.

/Users/zilence/.boot/cache/tmp/Users/zilence/765/d0ofpk/
/Users/zilence/.boot/cache/tmp/Users/zilence/765/11lgcg/
/Users/zilence/.boot/cache/tmp/Users/zilence/765/-p9hf6h/

I think boot always copies the :source-paths but when the paths change the incremental cache of shadow-cljs won't work.

Could maybe use a hash of the file contents instead of path+last-modified instead.

[thheller]

It now uses the lein classpath but that might actually create more problems than it solves.

Since shadow-cljs uses alpha16 clojure.spec.alpha it won't work with other versions of Clojure. The user may configure a different version in lein but not the normal approach of a tool specific classpath.

[thheller]

I'm thinking that it is getting less useful to use lein since shadow-cljs can now do the classpath itself.

It may be fine to just have all CLJS configuration in shadow-cljs.edn and not in lein.

The issue with lein (or boot) is that any non-CLJS dependencies may mess up shadow-cljs (ie. if you want to use Clojure 1.8.0). CLJS dependencies are usually more lightweight and keeping them out of lein solves a couple of issues.

[thheller]

With :lein {:profile "+cljs"} in shadow-cljs.edn the CLI script will launch the JVM using lein.

shadow-cljs --once
shadow-cljs - 1.0.20170615-09 using /Users/zilence/code/shadow-cljs/shadow-cljs.edn
shadow-cljs - running: lein with-profile +cljs run -m shadow.cljs.devtools.cli --npm --once

When using :lein the :source-paths and :dependencies of lein are used and not those of shadow-cljs.edn.

I want a similar integration with boot but don't know enough about it to write it as boot is about much more than just managing the classpath and launching a JVM. There is a lot of feature overlap and some decisions made by boot don't align well with shadow-cljs.