rails--rails/activesupport/CHANGELOG.md

*   Added support for error dispatcher classes in `ActiveSupport::Rescuable`. Now it acts closer to Ruby's rescue.

        class BaseController < ApplicationController
          module ErrorDispatcher
            def self.===(other)
              Exception === other && other.respond_to?(:status)
            end
          end

          rescue_from ErrorDispatcher do |error|
            render status: error.status, json: { error: error.to_s }
          end
        end

    *Genadi Samokovarov*

*   Added `#verified` and `#valid_message?` methods to `ActiveSupport::MessageVerifier`

    Previously, the only way to decode a message with `ActiveSupport::MessageVerifier` was to use `#verify`, which would raise an exception on invalid messages. Now `#verified` can also be used, which returns `nil` on messages that cannot be decoded.

    Previously, there was no way to check if a message's format was valid without attempting to decode it. `#valid_message?` is a boolean convenience method that checks whether the message is valid without actually decoding it.

    *Logan Leger*

Please check [4-2-stable](https://github.com/rails/rails/blob/4-2-stable/activesupport/CHANGELOG.md) for previous changes.