[BUG FIX] [MER-3847] Sort attempts by date_evaluated (#5131)

* sort attempts by date_evaluated

* add another list entry

* Auto format

* Update lib/oli/delivery/attempts/scoring.ex

Co-authored-by: Nicolás Cirio <nicolas.cirio@wyeworks.com>

* Auto format

* filter out nil dates

* Auto format

---------

Co-authored-by: darrensiegel <darrensiegel@users.noreply.github.com>
Co-authored-by: Nicolás Cirio <nicolas.cirio@wyeworks.com>

lib/oli/delivery/attempts/scoring.ex

@@ -63,7 +63,16 @@ defmodule Oli.Delivery.Attempts.Scoring do
 
   # The most recent is assumed to be the last item in the list
   def calculate_score("most_recent", items) do
-    most_recent = Enum.reverse(items) |> hd
+    # Sort the resource_attemmpts by the date_evaluated field, so that
+    # the most recent evaluated attempt is the first item in the list.
+    #
+    # This makes this scoring strategy a little more robust in the face of
+    # attempts where somehow the most recent attempt does not match
+    # the natural database order - or somehow the query doesn't return
+    # in database order.
+    [most_recent | _] =
+      Enum.filter(items, &(&1.date_evaluated != nil))
+      |> Enum.sort_by(& &1.date_evaluated, &(DateTime.compare(&1, &2) != :lt))
 
     %Result{
       score: Map.get(most_recent, :score),

test/oli/delivery/attempts/scoring_test.exs

@@ -20,11 +20,17 @@ defmodule Oli.Delivery.Attempts.ScoringTest do
   end
 
   test "most recent" do
-    items = [%{score: 5, out_of: 10}]
+    items = [%{score: 5, out_of: 10, date_evaluated: ~U[2021-01-01 00:00:00Z]}]
     assert %Result{score: 5, out_of: 10} = Scoring.calculate_score("most_recent", items)
 
-    items = [%{score: 5, out_of: 10}, %{score: 1, out_of: 20}]
-    assert %Result{score: 1, out_of: 20} = Scoring.calculate_score("most_recent", items)
+    items = [
+      %{score: 2, out_of: 10, date_evaluated: ~U[2019-01-01 00:00:00Z]},
+      %{score: 5, out_of: 10, date_evaluated: ~U[2023-01-01 00:00:00Z]},
+      %{score: 1, out_of: 20, date_evaluated: ~U[2021-01-01 00:00:00Z]},
+      %{score: 9, out_of: 20, date_evaluated: nil}
+    ]
+
+    assert %Result{score: 5, out_of: 10} = Scoring.calculate_score("most_recent", items)
   end
 
   test "best" do