Add option for class_attribute default (#29270)

* Allow a default value to be declared for class_attribute

* Convert to using class_attribute default rather than explicit setter

* Removed instance_accessor option by mistake

* False is a valid default value

* Documentation

2 files changed, 5 insertions, 6 deletions

diff --git a/railties/lib/rails/generators/testing/behaviour.rb b/railties/lib/rails/generators/testing/behaviour.rb
index 7a954a791d..ce0e42e60d 100644
--- a/railties/lib/rails/generators/testing/behaviour.rb
+++ b/railties/lib/rails/generators/testing/behaviour.rb
@@ -14,12 +14,12 @@ module Rails
         include ActiveSupport::Testing::Stream
 
         included do
-          class_attribute :destination_root, :current_path, :generator_class, :default_arguments
-
           # Generators frequently change the current path using +FileUtils.cd+.
           # So we need to store the path at file load and revert back to it after each test.
-          self.current_path = File.expand_path(Dir.pwd)
-          self.default_arguments = []
+          class_attribute :current_path, default: File.expand_path(Dir.pwd)
+          class_attribute :default_arguments, default: []
+          class_attribute :destination_root
+          class_attribute :generator_class
         end
 
         module ClassMethods
diff --git a/railties/lib/rails/test_unit/reporter.rb b/railties/lib/rails/test_unit/reporter.rb
index fe11664d5e..1cc27f7b6c 100644
--- a/railties/lib/rails/test_unit/reporter.rb
+++ b/railties/lib/rails/test_unit/reporter.rb
@@ -3,8 +3,7 @@ require "minitest"
 
 module Rails
   class TestUnitReporter < Minitest::StatisticsReporter
-    class_attribute :executable
-    self.executable = "bin/rails test"
+    class_attribute :executable, default: "bin/rails test"
 
     def record(result)
       super