Rails.cache.fetch is active in spite of ActionController::Base.perform_caching

[antoine-lizee]

I am not sure how to create a simple Minimal Working Example.
This happens when testing my caching behavior, and something along these lines fails:

  context "without cache" do

    it "should return the appropriate result, computing it every time", :caching => false do
      p ActionController::Base.perform_caching
      Object.should_receive(:where).exactly(4).and_call_original
      result1 = SomeService.action(args1, args2)
      result2 = SomeService.action(args1, args2)
    end

  end

...even though false is printed out for the ActionController::Base.perform_caching.
[I set this to false by the :caching => false option of the bloc (I use a hook)]

If I annihilate caching by switching from the default :memory_store to the :null_store for the testing environment, the test passes as expected.
[I just add config.cache_store = :null_store in test.rb]

My action method uses the core caching from Rails:

def action(args1, args2):
...
  objects = Rails.cache.fetch(cache_key, expires_in: 5.days) do
    object.where(id: args1).where(charac: args2).includes(...).to_a
  end
...
end

[matthewd]

This sounds like expected behaviour to me; maybe the documentation can be improved.

It says ActionController::Base.perform_caching can be used "to turn off all caching". It could be clearer, but it means "to turn off all caching involving this module" -- direct access to Rails.cache is entirely outside ActionController's responsibility.

If you want to prevent all caching, rather than just having AC opt out of using it, :null_store what you want.

[antoine-lizee]

Well, after looking at the code from the active_support library, I am wondering if low-level caching has ever been meant to answer from ActionController::Base.perform_caching... Maybe we should improve the documentation that is clearly misleading here: http://guides.rubyonrails.org/caching_with_rails.html

[antoine-lizee]

@matthewd Yeah, got it. But the caching guide of rails is clearly misleading - it talks about the perform_caching as if it governed the while thing, including the low level caching stuff it is describing later on. I'll propose a PR.

[antoine-lizee]

On a related note, what would involve supporting this?

[rails-bot]

This issue has been automatically marked as stale because it has not been commented on for at least
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The resources of the Rails team are limited, and so we are asking for your help.

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[antoine-lizee]

Closing, as the doc PR has been merged. Discussion could be restarted elsewhere if some new feature is desirable around this issue.