Clean up the cache before the request in case we are running in the reload_classes_only_on_change schema.

activerecord/lib/active_record/railtie.rb

@@ -85,11 +85,19 @@ module ActiveRecord
       end
     end
 
-    initializer "active_record.set_dispatch_hooks", :before => :set_clear_dependencies_hook do |app|
+    initializer "active_record.set_reloader_hooks" do |app|
-      ActiveSupport.on_load(:active_record) do
+      hook = lambda do
-        ActionDispatch::Reloader.to_cleanup do
+        ActiveRecord::Base.clear_reloadable_connections!
-          ActiveRecord::Base.clear_reloadable_connections!
+        ActiveRecord::Base.clear_cache!
-          ActiveRecord::Base.clear_cache!
+      end
+
+      if app.config.reload_classes_only_on_change
+        ActiveSupport.on_load(:active_record) do
+          ActionDispatch::Reloader.to_prepare(&hook)
+        end
+      else
+        ActiveSupport.on_load(:active_record) do
+          ActionDispatch::Reloader.to_cleanup(&hook)
         end
       end
     end

railties/lib/rails/application/finisher.rb

@@ -71,7 +71,7 @@ module Rails
 
       # Set app reload just after the finisher hook to ensure
       # paths added in the hook are still loaded.
-      initializer :set_dependencies_hook, :group => :all do
+      initializer :set_clear_dependencies_hook, :group => :all do
         callback = lambda do
           ActiveSupport::DescendantsTracker.clear
           ActiveSupport::Dependencies.clear

railties/test/application/console_test.rb

@@ -62,8 +62,6 @@ class ConsoleTest < Test::Unit::TestCase
     load_environment
     assert User.new.respond_to?(:name)
 
-    sleep(1)
-
     app_file "app/models/user.rb", <<-MODEL
       class User
         attr_accessor :name, :age

railties/test/application/loading_test.rb

@@ -120,7 +120,6 @@ class LoadingTest < Test::Unit::TestCase
     extend Rack::Test::Methods
 
     require "#{rails_root}/config/environment"
-    sleep(1)
 
     get "/c"
     assert_equal "1", last_response.body
@@ -160,7 +159,6 @@ class LoadingTest < Test::Unit::TestCase
     extend Rack::Test::Methods
 
     require "#{rails_root}/config/environment"
-    sleep(1)
 
     get "/c"
     assert_equal "1", last_response.body
@@ -175,7 +173,7 @@ class LoadingTest < Test::Unit::TestCase
     assert_equal "1", last_response.body
   end
 
-  test "added files also trigger reloading" do
+  test "added files (like db/schema.rb) also trigger reloading" do
     add_to_config <<-RUBY
       config.cache_classes = false
     RUBY
@@ -207,6 +205,56 @@ class LoadingTest < Test::Unit::TestCase
     assert_equal "2", last_response.body
   end
 
+  test "columns migrations also trigger reloading" do
+    add_to_config <<-RUBY
+      config.cache_classes = false
+    RUBY
+
+    app_file 'config/routes.rb', <<-RUBY
+      AppTemplate::Application.routes.draw do
+        match '/title', :to => lambda { |env| [200, {"Content-Type" => "text/plain"}, [Post.new.title]] }
+        match '/body',  :to => lambda { |env| [200, {"Content-Type" => "text/plain"}, [Post.new.body]] }
+      end
+    RUBY
+
+    app_file "app/models/post.rb", <<-MODEL
+      class Post < ActiveRecord::Base
+      end
+    MODEL
+
+    require 'rack/test'
+    extend Rack::Test::Methods
+
+    app_file "db/migrate/1_create_posts.rb", <<-MIGRATION
+      class CreatePosts < ActiveRecord::Migration
+        def change
+          create_table :posts do |t|
+            t.string :title, :default => "TITLE"
+          end
+        end
+      end
+    MIGRATION
+
+    Dir.chdir(app_path) { `rake db:migrate`}
+    require "#{rails_root}/config/environment"
+
+    get "/title"
+    assert_equal "TITLE", last_response.body
+
+    app_file "db/migrate/2_add_body_to_posts.rb", <<-MIGRATION
+      class AddBodyToPosts < ActiveRecord::Migration
+        def change
+          add_column :posts, :body, :text, :default => "BODY"
+        end
+      end
+    MIGRATION
+
+    Dir.chdir(app_path) { `rake db:migrate` }
+
+    get "/body"
+    assert_equal "BODY", last_response.body
+  end
+
   protected
 
   def setup_ar!

railties/test/application/rake/migrations_test.rb

@@ -86,7 +86,7 @@ module ApplicationTests
           `rails generate migration add_email_to_users email:string`
         end
 
-        Dir.chdir(app_path) { `rake db:migrate`}
+        Dir.chdir(app_path) { `rake db:migrate` }
         output = Dir.chdir(app_path) { `rake db:migrate:status` }
 
         assert_match(/up\s+\d{14}\s+Create users/, output)