Feature/endgame play (#1)

* create endgame play section

* add cache tests

* normalise FENs - trim and fuill move to 1 on addition

* remove svg on root and allow navbar to exist across all pages

* update nav items

test/chesstrainer/endgames_test.exs

@@ -0,0 +1,88 @@
+defmodule Chesstrainer.EndgamesTest do
+  use Chesstrainer.DataCase
+
+  alias Chesstrainer.Endgames
+  alias Chesstrainer.Endgames.Endgame
+
+  describe "create_endgame/1 FEN validation" do
+    test "accepts a standard valid FEN" do
+      attrs = %{
+        fen: "8/8/3k4/8/8/3K1R2/8/8 w - - 0 1",
+        color: :white,
+        key: "KR v K",
+        result: :win,
+        rating: 1500
+      }
+
+      assert {:ok, %Endgame{}} = Endgames.create_endgame(attrs)
+    end
+
+    test "normalizes fullmove 0 to 1 before inserting" do
+      attrs = %{
+        fen: "6k1/5p2/6p1/8/7p/8/6PP/6K1 b - - 0 0",
+        color: :black,
+        key: "KPPP v KPP",
+        result: :win,
+        rating: 1500
+      }
+
+      assert {:ok, endgame} = Endgames.create_endgame(attrs)
+      assert endgame.fen == "6k1/5p2/6p1/8/7p/8/6PP/6K1 b - - 0 1"
+    end
+
+    test "trims whitespace around the FEN before inserting" do
+      attrs = %{
+        fen: "  8/8/3k4/8/8/3K1R2/8/8 w - - 0 1\t\n",
+        color: :white,
+        key: "KR v K",
+        result: :win,
+        rating: 1500
+      }
+
+      assert {:ok, endgame} = Endgames.create_endgame(attrs)
+      assert endgame.fen == "8/8/3k4/8/8/3K1R2/8/8 w - - 0 1"
+    end
+
+    test "rejects a FEN with a zero digit in a rank" do
+      attrs = %{
+        fen: "4k3/8/8/8/8/8/8/0K7 w - - 0 1",
+        color: :white,
+        key: "KQ v K",
+        result: :win,
+        rating: 1500
+      }
+
+      assert {:error, changeset} = Endgames.create_endgame(attrs)
+      assert [msg] = errors_on(changeset).fen
+      assert msg =~ "board must be 8 ranks"
+    end
+
+    test "rejects a FEN with the wrong number of fields" do
+      attrs = %{
+        fen: "8/8/3k4/8/8/3K1R2/8/8",
+        color: :white,
+        key: "KQ v K",
+        result: :win,
+        rating: 1500
+      }
+
+      assert {:error, changeset} = Endgames.create_endgame(attrs)
+      assert [msg] = errors_on(changeset).fen
+      assert msg =~ "6 space-separated"
+    end
+
+    test "rejects a FEN with an unknown active color" do
+      attrs = %{
+        fen: "8/8/3k4/8/8/3K1R2/8/8 x - - 0 1",
+        color: :white,
+        key: "KQ v K",
+        result: :win,
+        rating: 1500
+      }
+
+      assert {:error, changeset} = Endgames.create_endgame(attrs)
+      assert [msg] = errors_on(changeset).fen
+      assert msg =~ "active color"
+    end
+  end
+end