fixes #3422

app/models/artist_url.rb

@@ -16,6 +16,10 @@ class ArtistUrl < ApplicationRecord
       url = url.gsub(/^http:\/\/blog-imgs-\d+-\w+\.fc2/, "http://blog.fc2")
       url = url.sub(%r!(http://seiga.nicovideo.jp/user/illust/\d+)\?.+!, '\1/')
       url = url.sub(%r!^http://pictures.hentai-foundry.com//!, "http://pictures.hentai-foundry.com/")
+
+      # the strategy won't always work for twitter because it looks for a status
+      url = url.downcase if url =~ /https?:\/\/(?:mobile\.)?twitter\.com/
+
       begin
         url = Sources::Site.new(url).normalize_for_artist_finder!
       rescue PixivApiClient::Error, Sources::Site::NoStrategyError

test/unit/artist_url_test.rb

@@ -3,6 +3,7 @@ require 'test_helper'
 class ArtistUrlTest < ActiveSupport::TestCase
   context "An artist url" do
     setup do
+      User.any_instance.stubs(:validate_sock_puppets)
       CurrentUser.user = FactoryGirl.create(:user)
       CurrentUser.ip_addr = "127.0.0.1"
     end
@@ -28,6 +29,16 @@ class ArtistUrlTest < ActiveSupport::TestCase
       assert_equal("http://google.com/", url.normalized_url)
     end
 
+    context "normalize twitter profile urls" do
+      setup do
+        @url = FactoryGirl.create(:artist_url, :url => "https://twitter.com/BLAH")
+      end
+
+      should "downcase the url" do
+        assert_equal("http://twitter.com/blah/", @url.normalized_url)
+      end
+    end
+
     should "normalize fc2 urls" do
       url = FactoryGirl.create(:artist_url, :url => "http://blog55.fc2.com/monet")
       assert_equal("http://blog55.fc2.com/monet", url.url)

test/unit/sources/twitter_test.rb

@@ -158,15 +158,5 @@ module Sources
         assert_equal(tags, @site.tags)
       end
     end
-
-    context "#normalize_for_artist_finder!" do
-      setup do
-        @site = Sources::Site.new("https://twitter.com/BLAH")
-      end
-
-      should "downcase the url" do
-        assert_equal("https://twitter.com/blah", @site.normalize_for_artist_finder!)
-      end
-    end
   end
 end