To enable adding the intro, the tracker knows visited modules.

test/tracker_test.exs

@@ -5,19 +5,24 @@ defmodule TrackerTest do
 
   test "can start" do
     Tracker.start(@sample_modules)
-    assert Tracker.summarize == %{total: 2, current: 0}
+    assert Tracker.summarize == %{total: 2, current: 0, visited_modules: []}
   end
 
   test "can be notified of completed koans" do
     Tracker.start(@sample_modules)
-    Tracker.completed(:"Hi there")
-    assert Tracker.summarize == %{total: 2, current: 1}
+    Tracker.completed(SampleKoan, :"Hi there")
+    assert Tracker.summarize == %{total: 2, current: 1, visited_modules: [SampleKoan]}
   end
 
   test "multiple comletions of the same koan count only once" do
     Tracker.start(@sample_modules)
-    Tracker.completed(:"Hi there")
-    Tracker.completed(:"Hi there")
-    assert Tracker.summarize == %{total: 2, current: 1}
+    Tracker.completed(SampleKoan, :"Hi there")
+    Tracker.completed(SampleKoan, :"Hi there")
+    assert Tracker.summarize == %{total: 2, current: 1, visited_modules: [SampleKoan]}
+  end
+
+  test "knows when koans are not complete" do
+    Tracker.start(@sample_modules)
+    refute Tracker.complete?
   end
 end