add more intelligent js for artist forms

test/unit/artist_test.rb

@@ -101,6 +101,18 @@ class ArtistTest < ActiveSupport::TestCase
       assert_equal(artist.name, artist.wiki_page.title)
     end
 
+    context "when a wiki page with the same name already exists" do
+      setup do
+        @wiki_page = FactoryGirl.create(:wiki_page, :title => "aaa")
+        @artist = FactoryGirl.build(:artist, :name => "aaa")
+      end
+
+      should "not validate" do
+        @artist.save
+        assert_equal(["Name conflicts with a wiki page"], @artist.errors.full_messages)
+      end
+    end
+
     should "update the wiki page when notes are assigned" do
       artist = FactoryGirl.create(:artist, :name => "aaa", :notes => "testing")
       artist.update_attribute(:notes, "kokoko")