private cache_path passed in as a symbol doesn't work in v1.2.0

[MarinaMurashev]

I'm running Rails 4.2.9 and Ruby 2.3.5. I just upgraded actionpack-action_caching gem from 1.1.1 to 1.2.0. Before, on v1.1.1 I was able to specify the cache_path with a symbolized method name (without the _url postfix), like this:

class MyController < ApplicationController
  caches_action :my_action, cache_path: :my_cache_path, if: :is_cacheable?

  def my_action
    ...
  end

  private

  def my_cache_path_url
    url_for(
      only_path: true, 
      action: "my_action", 
      format: "json", 
      page_number: params[:page],
      max_updated_at: MyModel.maximum(:updated_at).to_i,
    )
  end

  def is_cacheable?
    true
  end
end

After updating the gem to v1.2.0, this would only work if I wrapped the cache_path method in a new Proc with its full name including the _url portion:

caches_action :my_action, cache_path: Proc.new { my_cache_path_url }, if: :is_cacheable? # works

It also works with the short lambda syntax:

caches_action :my_action, cache_path: -> { my_cache_path_url }, if: :is_cacheable? # works

Can you verify whether v1.2.0 of the gem hurt the ability to pass in a symbolized url path name to cache_path?:

 caches_action :my_action, cache_path: :my_cache_path, if: :is_cacheable? # does not currently work

[MarinaMurashev]

UPDATE:

I tried moving my path method under protected instead of private and now its symbol version does work, with the _url postfix added on:

class MyController < ApplicationController
  caches_action :my_action, cache_path: :my_cache_path_url, if: :is_cacheable? # works

  def my_action
    ...
  end

  protected

  def my_cache_path_url
    url_for(
      only_path: true, 
      action: "my_action", 
      format: "json", 
      page_number: params[:page],
      max_updated_at: MyModel.maximum(:updated_at).to_i,
    )
  end

  private

  def is_cacheable?
    true
  end
end

If this is expected behavior, please make that more explicit in the readme -- that the symbolized cache path needs to be under protected and cannot be under private.