Unexpected behavior of render :json => obj

Hi,
sorry I left that out, long day.

The object is completely basic subclass of Exception

class ApiException < Exception
  
  def to_json
    return { :error => self.class.name, :message => self.to_str }.to_json
  end
  
end

Whenever the exception is raised, it is caught with this around_filter in my app controller:

  #application_controller.rb
  respond_to :json
  around_filter :catch_api_errors
  def catch_api_errors
    begin
      yield
    rescue ApiException => e
      respond_with e, :status => 400
    end
  end

I expect the output of this to be the result of :to_json being sent to the ApiException instance but instead I just the the value of :to_str

(from [4e2a981bdd162dfd52b15f34b4e45ba87726ff53]) If a user wants json output then try best to render json output. In such cases prefer kind_of(String) over respond_to?(to_str)

[#5841 Unexpected behavior of render :json => obj state:resolved]

Signed-off-by: José Valim jose.valim@gmail.com
https://github.com/rails/rails/commit/4e2a981bdd162dfd52b15f34b4e45...