Future deprecation message

1 files changed, 5 insertions, 1 deletions

diff --git a/activemodel/lib/active_model/deprecated_error_methods.rb b/activemodel/lib/active_model/deprecated_error_methods.rb
index b0d7023046..c3cc1d53ae 100644
--- a/activemodel/lib/active_model/deprecated_error_methods.rb
+++ b/activemodel/lib/active_model/deprecated_error_methods.rb
@@ -1,7 +1,11 @@
 module ActiveModel
   module DeprecatedErrorMethods
     def on(attribute)
-      # ActiveSupport::Deprecation.warn "Errors#on have been deprecated, use Errors#[] instead"
+      # message = "Errors#on have been deprecated, use Errors#[] instead.\n"
+      # message << "Also note that the behaviour of Errors#[] has changed. Errors#[] now always returns an Array and an empty Array when "
+      # message << "there are not errors on the specified attribute."
+      # ActiveSupport::Deprecation.warn(message)
+
       errors = self[attribute]
       errors.size < 2 ? errors.first : errors
     end