Only compile from before_action in test env

No longer invoke `EmberCli::App#compile` from within
`EmberCli::App#build` unless in the `test` environment.

When deploying to `production`-like environments,
`rake assets:precompile` will invoke `EmberCli::App#compile`.

When serving locally in `development`, compilation isn't necessary,
as we'll spawn an `ember build` into a separate process.

When testing, the first request to an Ember app will trigger a compile.

Author: seanpdoyle

CHANGELOG.md

@@ -1,6 +1,10 @@
 master
 ------
 
+* Invoke `EmberCli::App#compile` in `test` environment, spawn `build` process in
+  development, rely on `rake assets:precompile` in `production`-like
+  environments.
+
 0.5.0
 -----
 

lib/ember-cli/app.rb

@@ -35,9 +35,9 @@ def compile
     end
 
     def build
-      if EmberCli.env.development?
+      if development?
         build_and_watch
-      else
+      elsif test?
         compile
       end
 
@@ -59,7 +59,7 @@ def sprockets
     end
 
     def index_file
-      if EmberCli.env.production?
+      if production?
         paths.applications.join("#{name}.html")
       else
         paths.dist.join("index.html")
@@ -68,6 +68,12 @@ def index_file
 
     private
 
+    delegate :development?, :production?, :test?, to: :env
+
+    def env
+      EmberCli.env
+    end
+
     def build_and_watch
       prepare
       @shell.build_and_watch
@@ -84,7 +90,7 @@ def prepare
     end
 
     def copy_index_html_file
-      if EmberCli.env.production?
+      if production?
         FileUtils.cp(paths.app_assets.join("index.html"), index_file)
       end
     end