nijie: fetch artist commentary.

test/unit/sources/nijie_test.rb

@@ -23,6 +23,14 @@ module Sources
       should "get the tags" do
         assert_equal([["眼鏡", "http://nijie.info/search.php?word=%E7%9C%BC%E9%8F%A1"], ["リトルウィッチアカデミア", "http://nijie.info/search.php?word=%E3%83%AA%E3%83%88%E3%83%AB%E3%82%A6%E3%82%A3%E3%83%83%E3%83%81%E3%82%A2%E3%82%AB%E3%83%87%E3%83%9F%E3%82%A2"], ["アーシュラ先生", "http://nijie.info/search.php?word=%E3%82%A2%E3%83%BC%E3%82%B7%E3%83%A5%E3%83%A9%E5%85%88%E7%94%9F"]], @site.tags)
       end
+
+      should "get the commentary" do
+        title = "ジャージの下は"
+        desc = "「リトルウィッチアカデミア」から無自覚サキュバスぶりを発揮するアーシュラ先生です"
+
+        assert_equal(title, @site.artist_commentary_title)
+        assert_equal(desc, @site.artist_commentary_desc)
+      end
     end
 
     context "The source site for a nijie referer url" do