common cljs build format ideas

An_Explanation.md

A common build configuration format that all ClojureScript tools can consume

cljsbuilds1.edn

; A common shared Clojurescript build configuration file that can
; handle build tool specific concerns on a per build basis.

; in cljs-builds.edn
{ 
  ; id is a common concern among all tools
  :dev {
        ; source-paths is common concern among all tools
        :source-paths ["src" "dev"]
        
        ; build tool "build" specific concern
        :figwheel { :on-jsload 'example.core/reload }
        
        ; build tool "build" specific concern
        :cljbuild { :notify-command ["growl" "-f"] }
        
        :compiler { :output-to "example.js" 
                    :optimizations :none
                    ... }}}

; Question: should it be standard require eval on read?

; global build tool concerns (like server-port) can be implemented as a build tool desires...
; but it would be cool say if figwheel had a figwheel.edn and cljsbuild read a cljsbuild.edn 
; and doo had a doo.edn

; The figwheel.edn file could look as so

{:dev {:server-port 5000}
 :prod false}

; Edn files would allow folks to trivially read configuration in from scripts

cljsbuilds2.edn

; another approach would be to have a gereral build config that doesn't have any 
; build tool specific information in it
; I think I like this better

;cljs-builds.edn
; don't include any build tool specific information in this config
{:dev {:source-paths ["src" "dev"]
       :compiler { :output-to "example.js" 
                   :optimizations :none
                   ... }}}
                   
; in the project.clj the above could be entered like this
:cljs-builds { :dev {...}
               :prod {...}}

; The above has some real advantages.  We can write one library to read validate and thoroughly document this
; general configuration format. And then leave the tool specific validation to the individual tools.

; We then place "build" specific information in the build tool configuration wherever that may be

; figwheel.edn or in project.clj depending on mode of tool
{ :server-port 4555
  :builds {:dev {:on-jsload 'example.core/reload}} }

;this is cleaner but maybe less clear when someone is trying to understand the config

; in a project.clj the above could be entered under the :figwheel key like so
:figwheel { :server-port 4555 
            :builds {} }

Obvious downside is that we are changing things up on folks, yet again. But if we could rally around one central build config in one place I think the change would be worth it especially if we can share read and validation.