Optionally testing caching in Rails 3 functional tests

Question

Generally, I want my functional tests to not perform action caching. Rails seems to be on my side, defaulting to config.action_controller.perform_caching = false in environment/test.rb. This leads to normal functional tests not testing the caching.

So how do I test caching in Rails 3.

The solutions proposed in this thread seem rather hacky or taylored towards Rails 2: How to enable page caching in a functional test in rails?

I want to do something like:

test "caching of index method" do
  with_caching do
    get :index
    assert_template 'index'
    get :index
    assert_template ''
  end
end

Maybe there is also a better way of testing that the cache was hit?

Answer 1

You're liable to end up with tests stomping on each other. You should wrap this up with ensure and reset it to old values appropriately. An example:

module ActionController::Testing::Caching
  def with_caching(on = true)
    caching = ActionController::Base.perform_caching
    ActionController::Base.perform_caching = on
    yield
  ensure
    ActionController::Base.perform_caching = caching
  end

  def without_caching(&block)
    with_caching(false, &block)
  end
end

I've also put this into a module so you can just include this in your test class or parent class.