🐛 Preload the authors_mod on AuthorsUsersSeparatorUpdater

I really dodged a bullet by importing the production database and
testing that this worked manually, phew!

lib/authors_users_separation_updater.rb

@@ -1,16 +1,27 @@
 class AuthorsUsersSeparationUpdater
   def run
-    User.all.each do |user|
-      authors_mods = AuthorsMod.where(author_id: user.id)
+    all_users = User.all
+    all_authors_mods = all_users.map{|u| AuthorsMod.where(author_id: u.id).load }
+    all_users.each_with_index do |user, i|
+      #LN "============ Updating user: #{user.name} #{user.id}"
+      authors_mods = all_authors_mods[i]
       unless authors_mods.empty?
         author = Author.create! name: user.name, forum_name: user.name
-        authors_mods.update_all(author_id: author.id)
+        #LN "Has mods! Author created! #{author.id}"
+        authors_mods.each do |am|
+          #LN "Updating authors_mod #{am.mod.name}---#{user.name}   #{user.id} -> #{author.id}"
+          am.update! author_id: author.id
+        end
         Author.reset_counters(author.id, :mods)
         if user.autogenerated?
+          #LN "User was autogenerated, destroying!"
           user.destroy!
         elsif author.mods.where(owner: user).count > 0
+          #LN "User was legit and marked as owner! Associating them!"
           author.user = user
           author.save!
+        else
+          #LN "User was legit! But didn't have ownership of any mods!"
         end
       end
     end

spec/lib/authors_users_separation_updater_spec.rb

@@ -168,4 +168,27 @@ describe AuthorsUsersSeparationUpdater do
     expect(a2.mods).to match_array [m1]
     expect(a3.mods).to match_array [m3]
   end
+
+  it 'should not mess up with newly created AuthorsMod' do
+    # This will ensure us that IDs start at 1
+    DatabaseCleaner.strategy = :truncation
+    DatabaseCleaner.clean
+
+    u1 = create :user, name: 'Potato'
+    u2 = create :user, name: 'Galaxy'
+
+    # We create and destroy a new author so the next one starts with ID=2
+    # and we can break this thing!
+    Author.create!(name: 'Whatever').destroy!
+
+    m1 = create :mod, owner: nil, authors: []
+
+    create :authors_mod, mod_id: m1.id, author_id: u1.id
+
+    updater.run
+
+    expect(Author.count).to eq 1
+    a1 = Author.last
+    expect(a1.mods).to match_array [m1]
+  end
 end