Replace homebrew scheduling logic with Rufus

lib/lesson.rb

@@ -1,3 +1,5 @@
+require "rufus-scheduler"
+
 DEFAULT_LESSON_PLAN = [
   [15, "login and catch up on the week"],
   [45, "review chapter vocab and grammar"],
@@ -6,30 +8,34 @@ DEFAULT_LESSON_PLAN = [
 ]
 
 class Lesson
-  attr_reader :lesson_plan, :channel, :thread, :running
+  attr_reader :lesson_plan, :channel, :thread, :running, :scheduler
 
-  def initialize(lesson_plan=DEFAULT_LESSON_PLAN)
+  def initialize(lesson_plan=DEFAULT_LESSON_PLAN, scheduler: Rufus::Scheduler.new)
     @lesson_plan = lesson_plan
     @running = false
+    @scheduler = scheduler
   end
 
   def stop!
-    thread.kill if thread
-    @running = false
+    @scheduler.shutdown
   end
 
   def start!(channel)
-    stop!
-    @channel = channel
-    @thread = Thread.new do
-      @running = true
-      lesson_plan.each do |time, message|
+    lesson_plan.each_with_index do |(time, message), index|
+      offset = lesson_plan.map(&:first)[0..index - 1].sum(0)
+      offset = 0 if index == 0
+      scheduler.in "#{offset}m" do
         channel.send_message "#{time} minutes to #{message}"
-        sleep(time * 60)
       end
+    end
+
+    end_offset = lesson_plan.map(&:first).sum(0)
+    scheduler.in "#{end_offset}m" do
       channel.send_message "Lesson over!"
       @running = false
     end
+
+    @running = true
   end
 
   def running?

test/test_lesson.rb

@@ -3,20 +3,14 @@ require "minitest/autorun"
 
 class TestLesson < Minitest::Test
   def setup
-    @lesson = Lesson.new [[0.1 / 60, "test the thing"], [0.1 / 60, "finish testing"]]
+    @scheduler = Minitest::Mock.new
   end
 
   def test_start
-    @channel = Minitest::Mock.new
-    @channel.expect(:send_message, nil) { |msg| msg.include? "to test the thing" }
-    @channel.expect(:send_message, nil) { |msg| msg.include? "to finish testing" }
-    @channel.expect(:send_message, nil) { |msg| msg == "Lesson over!" }
-    assert_equal false, @lesson.running
-    @lesson.start!(@channel)
-    sleep(0.5)
-    # gonna be impossible to thread this needle
-    # assert_equal true, @lesson.running
-    sleep(0.5)
-    assert_equal false, @lesson.running
+    @lesson = Lesson.new [[1, "test the thing"], [3, "finish testing"]], scheduler: @scheduler
+    @scheduler.expect(:in, nil) { |time| time == "0m" }
+    @scheduler.expect(:in, nil) { |time| time == "1m" }
+    @scheduler.expect(:in, nil) { |time| time == "4m" }
+    @lesson.start! nil
   end
 end