在特定日期后每三天发送一次提醒电子邮件

Question

这是我的第一篇文章，对于任何新手的错误，请提前道歉。我已尝试研究解决此问题的不同解决方案，但到目前为止还没有找到适合我特定情况的解决方案。

我有一个应用程序，个人创建 evaluations，如果在 created_at 日期后 7 天仍未满足最低要求，我想每 3 天发送一次提醒电子邮件，提示他们采取行动。

reminders.rb 文件如下所示，Evaluation::ASSESSMENTS_COMPLETION_WAIT_TIME 设置为 7.days，Reminders::LIMBO_EMAIL_INTERVAL_DAYS 设置为 3：

def self.send_peer_shortage_notifications
    time = Time.current - Evaluation::ASSESSMENTS_COMPLETION_WAIT_TIME
    range = time..Time.current
    today = Time.current.to_date

    evaluations = Evaluation.arel_table
    assessments = Assessment.arel_table

    left_join = evaluations
                .join(assessments, Arel::Nodes::OuterJoin)
                .on(evaluations[:id].eq(assessments[:evaluation_id]),
                    assessments[:state].in([:pending, :complete]),
                    assessments[:assessor_id].not_in([evaluations[:user_id],
                                                      evaluations[:manager_id]]))
                .join_sources

    relation = Evaluation
               .in_process
               .joins(left_join)
               .where(created_at: range)
               .group(:user_id)
               .having(evaluations[:user_id].count.lt(Evaluation::MINIMUM_NUM_PEERS))

    relation.find_each do |evaluation|
      days_in_limbo = (today - (evaluation.created_at + Evaluation::ASSESSMENTS_COMPLETION_WAIT_TIME).to_date).to_i
      if days_in_limbo % Reminders::LIMBO_EMAIL_INTERVAL_DAYS == 0
        EvaluationMailer.delay.limbo_notification(evaluation)
      end
    end
  end

我的reminders_rspec.rb 看起来像这样（第一次测试失败，我不知道为什么）：

context 'minimum number of peer assessments not in pending/complete and limbo email interval day' do
      limbo_interval_array = Array.new(10) { |i| i*Reminders::LIMBO_EMAIL_INTERVAL_DAYS }

      let!(:evaluation) { create(:evaluation, created_at: (Evaluation::ASSESSMENTS_COMPLETION_WAIT_TIME + limbo_interval_array.sample.days).ago) }
      let!(:assessments) do
        create_list(:assessment,
        Evaluation::MINIMUM_NUM_PEERS,
        evaluation: evaluation,
        state: [:expired, :declined].sample)
      end

      it 'sends limbo email' do
        expect { subject }.to change { ActionMailer::Base.deliveries.count }.by(1)
      end
    end

    context 'on every non-third day since limbo' do
      array = (1..20).to_a
      limbo_interval_array = Array.new(10) { |i| i*Reminders::LIMBO_EMAIL_INTERVAL_DAYS }
      non_limbo_interval_array = array - limbo_interval_array


      let!(:evaluation) { create(:evaluation, created_at: (Evaluation::ASSESSMENTS_COMPLETION_WAIT_TIME + non_limbo_interval_array.sample.days).ago) }
      let!(:assessments) do
        create_list(:assessment,
        Evaluation::MINIMUM_NUM_PEERS,
        evaluation: evaluation,
        state: [:expired, :declined].sample)
      end

      it 'sends nothing' do
        expect { subject }.to change { ActionMailer::Base.deliveries.count }.by(0)
      end
    end

有没有更简单的方法来编写和测试它？对于我正在尝试做的事情来说，这似乎过于复杂，但我无法找到更简单的方法。

Answer 1

确实，您似乎让这变得比需要的更复杂。这里的关键是您希望使用队列后端来异步发送电子邮件通知。由于提醒将在创建评估后 7 天发送，因此延迟的电子邮件将在EvaluationsController 的#create 操作中排队：

class EvaluationsController < ApplicationController

def create
  # Do whatever it is you do to create an evaluation

  if @evaluation.valid?
     EvaluationMailer.delay_for(7.days).limbo_notification(evaluation.id)  # Pass an ID rather than a model object, and use `find_by` within `limbo_notification`
     # redirect or whatever...
  end
end

现在，所有繁重的工作都将由您的排队后端ActiveJob 完成，它将在 7 天后自动为您发送电子邮件。

队列后端是一个大主题，我不会详细说明它们的工作原理，而是将您指向此处的文档：http://edgeguides.rubyonrails.org/active_job_basics.html。对于特定的队列后端，我建议使用带有 Redis 的 Sidekiq。