How to determine whether any prerequisite tasks needed to run at the time they were defined?

issue に示されている Rake::Task のエントリポイント、#needed?、#already_invoked、#execute、#enhance、invoke_prerequisites から始めます。それぞれの状態がいつ変化するかを追跡し、実際に実行された prerequisite と、呼び出されただけの prerequisite を区別する方法を明らかにします。両方のケースについて動作が仕様化され、テストでカバーされていれば完了です。

I have a use-case in which I need to run a task if and only if at least one of its prerequisite tasks either (1) currently needs to run or (2) needed to run at the time the prerequisite task was defined. Here are some attempts at a Rake::Task subclass:

class MyTask < Rake::Task
  def needed?
    prerequisite_tasks.any?(&:needed?)
  end
end

This approach does not work, since at the time MyTask#needed? is called, prerequisite tasks may have run and therefore return false for #needed?.

class MyTask < Rake::Task
  def needed?
    prerequisite_tasks.any? { |p| p.needed? or p.already_invoked }
  end
end

This also doesn't work, since #already_invoked can return true [even if the task's #execute method was never called]:

          @already_invoked = true


          invoke_prerequisites(task_args, new_chain)
          execute(task_args) if needed?

What ended up working was:

class MyTask < Rake::Task
  def initialize(*)
    @needed = false
    super
  end
  
  def enhance(*)
    super.tap { @needed |= prerequisite_tasks.any?(&:needed?) }
  end

  def needed?
    @needed
  end
end

But that just feels... wrong. Is there something I'm missing here? I'd be more than happy to open a PR implementing what I'm looking for (maybe an #already_executed method?) if this functionality doesn't already exist.

Thanks!