Support getting artist bios from Wikipedia (experimental)

test/music_brainz/artist_test.exs

@@ -0,0 +1,27 @@
+defmodule MusicBrainz.ArtistTest do
+  use ExUnit.Case, async: true
+
+  alias MusicBrainz.Artist
+
+  describe "get_wikidata_id/1" do
+    test "extracts wikidata ID from relations" do
+      artist_data = MusicBrainz.Fixtures.Artist.get_artist()
+      artist = Artist.from_api_response(artist_data)
+
+      assert Artist.get_wikidata_id(artist) == "Q352766"
+    end
+
+    test "returns nil when no wikidata relation exists" do
+      artist = %Artist{
+        id: "test",
+        name: "Test",
+        sort_name: "Test",
+        relations: [
+          %{type: "discogs", url: %{"resource" => "https://www.discogs.com/artist/123"}}
+        ]
+      }
+
+      assert Artist.get_wikidata_id(artist) == nil
+    end
+  end
+end