allow empty favs list

app/lib/domain/fa/parser/user_page_helper.rb

@@ -151,7 +151,7 @@ class Domain::Fa::Parser::UserPageHelper < Domain::Fa::Parser::Base
           /\/view\/(\d+)/.match(href)[1]&.to_i || raise(
             "invalid url: #{href}"
           )
-        end
+        end || []
       else unimplemented_version!
       end
   end

spec/lib/domain/fa/parser/redux_page_spec.rb

@@ -364,6 +364,17 @@ describe Domain::Fa::Parser::Page do
     assert_equal up.registered_since, DateTime.parse("Sep 7, 2018 06:19")
   end
 
+  it "handles pages with no favorites" do
+    parser = get_parser("azurathefox_user_page.html")
+    assert_page_type parser, :probably_user_page?
+    up = parser.user_page
+    assert_equal up.name, "AzuraTheFox"
+    assert_equal up.recent_fav_fa_ids, []
+    assert_equal up.recent_watchers.first.to_a, ["SN214549", "sn214549"]
+    assert_equal up.recent_watchers.last.to_a, ["Duckyou7464", "duckyou7464"]
+    assert_equal up.recent_watching, []
+  end
+
   def get_parser(file, require_logged_in: true)
     path = File.join("domain/fa/parser/redux", file)
     contents = SpecUtil.read_fixture_file(path) || raise("Couldn't open #{path}")