Interactions between Lolex, Timecop and the Cache in HyperSpec

先定位 HyperSpec::Internal::Controller 的 cache_read、cache_write 和 cache_delete 方法，然後檢查 Lolex.evaluate_ruby，以及 Filecache 和 Timecop 在其中如何互動。完成的標準是快取操作使用系統時間，並且在 HyperSpec 未掛載時保留 Lolex 更新，同時不傳送不必要的用戶端通訊。

Hyperspec uses the Filecache gem, which uses Time.now. But if Timecop freezes time in a spec, then Time.now is not returning the system time, and the Filecache does not work. This should be fixable by wrapping calls to the Filecache with the timecop return method (and a block.) But this does not in general work because Hyperspec tries to communicate the "return" to the client, even if the client is not running.

The following series of patches fixes the issue, and can be incorporated into the next point release:

module HyperSpec
  module Internal
    module Controller
      class << self
        # wrap all calls with Timecop.return so the file cache gets the true system time
        def cache_read(key)
          Timecop.return { file_cache.get(key) }
        end

        def cache_write(key, value)
          Timecop.return { file_cache.set(key, value) }
        end

        def cache_delete(key)
          Timecop.return { file_cache.delete(key) }
        rescue StandardError
          nil
        end
      end
    end
  end
end

class Lolex
  # store all lolex updates unless hyper_spec is mounted
  def self.evaluate_ruby(&block)
    if @capybara_page&.instance_variable_get('@hyper_spec_mounted')
      @capybara_page.internal_evaluate_ruby(yield)
    else
      pending_evaluations << block
    end
  end
end