Congratulate when koans are complete

lib/meditate.ex

@@ -16,6 +16,8 @@ defmodule Mix.Tasks.Meditate do
     |> Tracker.start
     |> Runner.run
 
+    if Tracker.complete?, do: Display.congratulate
+
     receive do
       {:DOWN, _references, :process, watcher, _reason} -> nil
     end

lib/tracker.ex

@@ -19,6 +19,11 @@ defmodule Tracker do
     end)
   end
 
+  def complete? do
+    {total, completed} = Agent.get(__MODULE__, &(&1))
+    total == Enum.count(completed)
+  end
+
   def summarize({total, completed}) do
     %{total: total, current: MapSet.size(completed)}
   end

lib/watcher.ex

@@ -12,6 +12,8 @@ defmodule Watcher do
       rescue
         e -> Display.show_compile_error(e)
       end
+
+      if Tracker.complete?, do: Display.congratulate
     end
   end
 end