Don't cache classes unless the environment permits it

Fixes #264.

Author: jonleighton

CHANGELOG.md

@@ -6,6 +6,7 @@
 * Avoid `warning: already initialized constant APP_PATH` when running
   rails commands that do not use spring (e.g. `bin/rails server` would
   emit this when you ^C to exit)
+* Fix `reload!` in rails console
 
 ## 1.1.1
 

lib/spring/application.rb

@@ -91,7 +91,9 @@ def preload
 
       require Spring.application_root_path.join("config", "environment")
 
+      @original_cache_classes = Rails.application.config.cache_classes
       Rails.application.config.cache_classes = false
+
       disconnect_database
 
       @preloaded = :success
@@ -161,9 +163,13 @@ def serve(client)
         # Load in the current env vars, except those which *were* changed when spring started
         env.each { |k, v| ENV[k] ||= v }
 
-        # requiring is faster, and we don't need constant reloading in this process
-        ActiveSupport::Dependencies.mechanism = :require
-        Rails.application.config.cache_classes = true
+        # requiring is faster, so if config.cache_classes was true in
+        # the environment's config file, then we can respect that from
+        # here on as we no longer need constant reloading.
+        if @original_cache_classes
+          ActiveSupport::Dependencies.mechanism = :require
+          Rails.application.config.cache_classes = true
+        end
 
         connect_database
         srand