Ok - the state of things

Things pass except for the fixture connection tests and one test that
is getting too many shards in the list because we're no longer cleaning
up connections at the end of the tests.

We need a way I think to turn off shared connection pools for the AR
tests, or at least when we're not doing multi-connection work.

rails#40384 is interesting but I didn't
have time to make it work with our stuff.

So basically we're in a better state but I'm not quite sure yet how to
get just the 2 tests that need shared pools to use them. Thoughts?

activerecord/lib/active_record/test_fixtures.rb

@@ -189,19 +189,22 @@ def enlist_fixture_connections
       # need to share a connection pool so that the reading connection
       # can see data in the open transaction on the writing connection.
       def setup_shared_connection_pool
+        return if ENV["OFFFFFFF"]
         if ActiveRecord::Base.legacy_connection_handling
-          writing_handler = ActiveRecord::Base.connection_handlers[ActiveRecord::Base.writing_role]
+          ActiveSupport::Deprecation.silence do
+            writing_handler = ActiveRecord::Base.connection_handlers[ActiveRecord::Base.writing_role]
 
-          ActiveRecord::Base.connection_handlers.values.each do |handler|
-            if handler != writing_handler
-              handler.connection_pool_names.each do |name|
-                writing_pool_manager = writing_handler.send(:owner_to_pool_manager)[name]
-                return unless writing_pool_manager
+            ActiveRecord::Base.connection_handlers.values.each do |handler|
+              if handler != writing_handler
+                handler.connection_pool_names.each do |name|
+                  writing_pool_manager = writing_handler.send(:owner_to_pool_manager)[name]
+                  return unless writing_pool_manager
 
-                writing_pool_config = writing_pool_manager.get_pool_config(nil, :default)
+                  writing_pool_config = writing_pool_manager.get_pool_config(nil, :default)
 
-                pool_manager = handler.send(:owner_to_pool_manager)[name]
-                pool_manager.set_pool_config(nil, :default, writing_pool_config)
+                  pool_manager = handler.send(:owner_to_pool_manager)[name]
+                  pool_manager.set_pool_config(nil, :default, writing_pool_config)
+                end
               end
             end
           end

activerecord/test/cases/base_prevent_writes_test.rb

@@ -202,7 +202,6 @@ def teardown
       end
 
       test "preventing writes with multiple handlers" do
-        skip "ugg"
         ActiveRecord::Base.connects_to(database: { writing: :arunit, reading: :arunit })
 
         conn1_error = assert_raises ActiveRecord::ReadOnlyError do

activerecord/test/cases/fixtures_test.rb

@@ -1404,11 +1404,11 @@ def setup
 
       handler = ActiveRecord::ConnectionAdapters::ConnectionHandler.new
       handler.establish_connection(db_config)
-      assert_deprecated do
-        ActiveRecord::Base.connection_handlers = {}
-      end
       ActiveRecord::Base.connection_handler = handler
+
       ActiveRecord::Base.connects_to(database: { writing: :default, reading: :readonly })
+
+      setup_shared_connection_pool
     end
 
     def teardown
@@ -1428,15 +1428,76 @@ def test_uses_writing_connection_for_fixtures
     end
 
     def test_writing_and_reading_connections_are_the_same
-      if ActiveRecord::Base.legacy_connection_handling
-        rw_conn = ActiveRecord::Base.connection_handlers[:writing].connection_pool_list.first.connection
-        ro_conn = ActiveRecord::Base.connection_handlers[:reading].connection_pool_list.first.connection
-      else
-        rw_conn = ActiveRecord::Base.connection_handler.connection_pool_list(:writing).first.connection
-        ro_conn = ActiveRecord::Base.connection_handler.connection_pool_list(:reading).first.connection
+      rw_conn = ActiveRecord::Base.connection_handler.connection_pool_list(:writing).first.connection
+      ro_conn = ActiveRecord::Base.connection_handler.connection_pool_list(:reading).first.connection
+
+      assert_equal rw_conn, ro_conn
+    end
+
+    private
+      def config
+        { "default" => default_config, "readonly" => readonly_config }
+      end
+
+      def default_config
+        { "adapter" => "sqlite3", "database" => "test/fixtures/fixture_database.sqlite3" }
+      end
+
+      def readonly_config
+        default_config.merge("replica" => true)
+      end
+  end
+
+  class MultipleFixtureLegacyConnectionsTest < ActiveRecord::TestCase
+    include ActiveRecord::TestFixtures
+
+    fixtures :dogs
+
+    def setup
+      @old_value = ActiveRecord::Base.legacy_connection_handling
+      ActiveRecord::Base.legacy_connection_handling = true
+
+      @old_handler = ActiveRecord::Base.connection_handler
+      @prev_configs, ActiveRecord::Base.configurations = ActiveRecord::Base.configurations, config
+      db_config = ActiveRecord::DatabaseConfigurations::HashConfig.new(ENV["RAILS_ENV"], "readonly", readonly_config)
+
+      handler = ActiveRecord::ConnectionAdapters::ConnectionHandler.new
+      assert_deprecated do
+        handler.establish_connection(db_config)
+        ActiveRecord::Base.connection_handlers = {}
       end
+      ActiveRecord::Base.connection_handler = handler
+      ActiveRecord::Base.connects_to(database: { writing: :default, reading: :readonly })
+
+      setup_shared_connection_pool
+    end
+
+    def teardown
+      ActiveRecord::Base.configurations = @prev_configs
+      ActiveRecord::Base.connection_handler = @old_handler
+      ActiveRecord::Base.legacy_connection_handling = false
+    end
+
+    def test_uses_writing_connection_for_fixtures
+      ActiveRecord::Base.connected_to(role: :reading) do
+        Dog.first
+
+        assert_nothing_raised do
+          ActiveRecord::Base.connected_to(role: :writing) { Dog.create! alias: "Doggo" }
+        end
+      end
+    end
+
+    def test_writing_and_reading_connections_are_the_same_with_legacy_handling
+      writing = assert_deprecated { ActiveRecord::Base.connection_handlers[:writing] }
+      reading = assert_deprecated { ActiveRecord::Base.connection_handlers[:reading] }
+
+      rw_conn = assert_deprecated { writing.connection_pool_list.first.connection }
+      ro_conn = assert_deprecated { reading.connection_pool_list.first.connection }
 
       assert_equal rw_conn, ro_conn
+    ensure
+      ActiveRecord::Base.legacy_connection_handling = @old_value
     end
 
     private

activerecord/test/cases/helper.rb

@@ -150,26 +150,9 @@ def disable_extension!(extension, connection)
 end
 
 def clean_up_legacy_connection_handlers
-  handler = ActiveRecord::Base.default_connection_handler
-  assert_deprecated do
-    ActiveRecord::Base.connection_handlers = { ActiveRecord::Base.writing_role => handler }
-  end
-
-  handler.connection_pool_names.each do |name|
-    next if ["ActiveRecord::Base", "ARUnit2Model", "Contact", "ContactSti"].include?(name)
-
-    handler.send(:owner_to_pool_manager).delete(name)
-  end
 end
 
 def clean_up_connection_handler
-  handler = ActiveRecord::Base.connection_handler
-  handler.instance_variable_get(:@owner_to_pool_manager).each do |owner, pool_manager|
-    pool_manager.role_names.each do |role_name|
-      next if role_name == ActiveRecord::Base.default_role
-      pool_manager.remove_role(role_name)
-    end
-  end
 end
 
 def load_schema