Allow users to choose when to eager_load the application or not.

Previously, the eager load behavior was mostly coupled to
config.cache_classes, however this was suboptimal since in
some environments a developer may want to cache classes but
not necessarily load them all on boot (for example, test env).

This pull request also promotes the use of config.eager_load
set to true by default in production. In the majority of the
cases, this is the behavior you want since it will copy most
of your app into memory on boot (which was also the previous
behavior).

Finally, this fix a long standing Rails bug where it was
impossible to access a model in a rake task when Rails was
set as thread safe.

1 files changed, 5 insertions, 0 deletions

diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt
index 878deb49d7..8ab27eb6e1 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/test.rb.tt
@@ -7,6 +7,11 @@
   # and recreated between test runs. Don't rely on the data there!
   config.cache_classes = true
 
+  # Do not eager load code on boot. This avoids loading your whole application
+  # just for the purpose of running a single test. If you are using a tool that
+  # preloads Rails for running tests, you may have to set it to true.
+  config.eager_load = false
+
   # Configure static asset server for tests with Cache-Control for performance.
   config.serve_static_assets = true
   config.static_cache_control = "public, max-age=3600"