Fix ArtistInfo.country/1 crash when area is missing

lib/music_library/artists/artist_info.ex

@@ -37,8 +37,7 @@ defmodule MusicLibrary.Artists.ArtistInfo do
 
   @spec country(t()) :: %{name: String.t(), code: String.t()}
   def country(artist_info) do
-    %{"area" => area} =
-      artist_info.musicbrainz_data
+    area = Map.get(artist_info.musicbrainz_data, "area", %{})
 
     country_code =
       case area["iso-3166-1-codes"] || area["iso-3166-2-codes"] do

test/music_library/artists/artist_info_test.exs

@@ -0,0 +1,60 @@
+defmodule MusicLibrary.Artists.ArtistInfoTest do
+  use MusicLibrary.DataCase, async: true
+
+  alias MusicLibrary.Artists.ArtistInfo
+
+  describe "country/1" do
+    test "returns country from area with ISO 3166-1 codes" do
+      artist_info = %ArtistInfo{
+        musicbrainz_data: %{
+          "area" => %{
+            "name" => "United Kingdom",
+            "iso-3166-1-codes" => ["GB"]
+          }
+        }
+      }
+
+      assert ArtistInfo.country(artist_info) == %{name: "United Kingdom", code: "GB"}
+    end
+
+    test "returns country from area with ISO 3166-2 codes" do
+      artist_info = %ArtistInfo{
+        musicbrainz_data: %{
+          "area" => %{
+            "name" => "England",
+            "iso-3166-2-codes" => ["GB-ENG"]
+          }
+        }
+      }
+
+      assert ArtistInfo.country(artist_info) == %{name: "England", code: "GB-ENG"}
+    end
+
+    test "falls back to top-level country when area has no ISO codes" do
+      artist_info = %ArtistInfo{
+        musicbrainz_data: %{
+          "country" => "US",
+          "area" => %{"name" => "United States"}
+        }
+      }
+
+      assert ArtistInfo.country(artist_info) == %{name: "United States", code: "US"}
+    end
+
+    test "returns defaults when area key is missing" do
+      artist_info = %ArtistInfo{
+        musicbrainz_data: %{}
+      }
+
+      assert ArtistInfo.country(artist_info) == %{name: "World", code: "XW"}
+    end
+
+    test "falls back to top-level country when area is missing" do
+      artist_info = %ArtistInfo{
+        musicbrainz_data: %{"country" => "JP"}
+      }
+
+      assert ArtistInfo.country(artist_info) == %{name: "World", code: "JP"}
+    end
+  end
+end