Fix #5002: "Urls url has already been taken" when submitting duplicate urls with different capitalization

Fix URLs being normalized after checking for duplicates rather than
before, which meant that URLs that differed in capitalization weren't
detected as duplicates.

app/logical/artist_finder.rb

@@ -149,7 +149,7 @@ module ArtistFinder
   # @param url [String] the artist profile URL
   # @return [Array<Artist>] the list of matching artists
   def find_artists(url)
-    url = ArtistUrl.normalize(url)
+    url = ArtistUrl.normalize_normalized_url(url)
     artists = []
 
     while artists.empty? && url.size > 10

app/models/artist_url.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
 class ArtistUrl < ApplicationRecord
-  before_validation :initialize_normalized_url, on: :create
-  before_validation :normalize
+  normalize :url, :normalize_url
+
   validates :url, presence: true, uniqueness: { scope: :artist_id }
   validate :validate_url_format
   belongs_to :artist, :touch => true
@@ -18,7 +18,7 @@ class ArtistUrl < ApplicationRecord
     [is_active, url]
   end
 
-  def self.normalize(url)
+  def self.normalize_normalized_url(url)
     if url.nil?
       nil
     else
@@ -29,7 +29,7 @@ class ArtistUrl < ApplicationRecord
       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 =~ %r{^https?://(?:mobile\.)?twitter\.com}
+      url = url.downcase if url =~ %r{^https?://(?:mobile\.)?twitter\.com}i
 
       url = Sources::Strategies.find(url).normalize_for_artist_finder
 
@@ -67,7 +67,7 @@ class ArtistUrl < ApplicationRecord
     elsif url.include?("*")
       where_ilike(attr, url)
     else
-      where(attr => normalize(url))
+      where(attr => normalize_normalized_url(url))
     end
   end
 
@@ -118,20 +118,17 @@ class ArtistUrl < ApplicationRecord
     sites.index(site_name) || 1000
   end
 
-  def normalize
-    # Perform some normalization with Addressable on the URL itself
-    # - Converts scheme and hostname to downcase
-    # - Converts unicode hostname to Punycode
+  def self.normalize_url(url)
     uri = Addressable::URI.parse(url)
     uri.site = uri.normalized_site
-    self.url = uri.to_s
-    self.normalized_url = self.class.normalize(url)
+    uri.to_s
   rescue Addressable::URI::InvalidURIError
-    # Don't bother normalizing the URL if there is errors
+    url
   end
 
-  def initialize_normalized_url
-    self.normalized_url = url
+  def url=(url)
+    super(url)
+    self.normalized_url = self.class.normalize_normalized_url(self.url)
   end
 
   def to_s

test/unit/artist_test.rb

@@ -158,6 +158,13 @@ class ArtistTest < ActiveSupport::TestCase
       assert_equal(old_url_ids, ArtistUrl.order("id").pluck(&:id))
     end
 
+    should "normalize urls before removing duplicates" do
+      @artist = create(:artist, url_string: "https://Twitter.com/o8q https://twitter.com/o8q")
+
+      assert_equal(1, @artist.urls.count)
+      assert_equal(["https://twitter.com/o8q"], @artist.urls.map(&:to_s))
+    end
+
     should "ignore pixiv.net/ and pixiv.net/img/ url matches" do
       a1 = FactoryBot.create(:artist, :name => "yomosaka", :url_string => "http://i2.pixiv.net/img18/img/evazion/14901720.png")
       a2 = FactoryBot.create(:artist, :name => "niwatazumi_bf", :url_string => "http://i2.pixiv.net/img18/img/evazion/14901720_big_p0.png")