Speed up development by only reloading classes if dependencies files changed.

This can be turned off by setting `config.reload_classes_only_on_change` to false.

Extensions like Active Record should add their respective files like db/schema.rb and db/structure.sql to `config.watchable_files` if they want their changes to affect classes reloading.

Thanks to https://github.com/paneq/active_reload and Pastorino for the inspiration. <3

1 files changed, 13 insertions, 0 deletions

diff --git a/activesupport/test/file_update_checker_test.rb b/activesupport/test/file_update_checker_test.rb
index a5a9b7a682..52c1f3260d 100644
--- a/activesupport/test/file_update_checker_test.rb
+++ b/activesupport/test/file_update_checker_test.rb
@@ -54,6 +54,19 @@ class FileUpdateCheckerWithEnumerableTest < Test::Unit::TestCase
     assert_equal 1, i
   end
 
+  def test_should_cache_updated_result_until_flushed
+    i = 0
+    checker = ActiveSupport::FileUpdateChecker.new(FILES, true){ i += 1 }
+    assert !checker.updated?
+
+    sleep(1)
+    FileUtils.touch(FILES)
+
+    assert checker.updated?
+    assert checker.execute_if_updated
+    assert !checker.updated?
+  end
+
   def test_should_invoke_the_block_if_a_watched_dir_changed_its_glob
     i = 0
     checker = ActiveSupport::FileUpdateChecker.new([{"tmp_watcher" => [:txt]}], true){ i += 1 }