Fix run_after_commit_or_now to use model's connection

app/models/concerns/after_commit_queue.rb

@@ -15,8 +15,8 @@ module AfterCommitQueue
   end
 
   def run_after_commit_or_now(&block)
-    if ApplicationRecord.inside_transaction?
-      if ActiveRecord::Base.connection.current_transaction.records&.include?(self) # rubocop: disable Database/MultipleDatabases
+    if self.class.inside_transaction?
+      if connection.current_transaction.records&.include?(self)
         run_after_commit(&block)
       else
         # If the current transaction does not include this record, we can run

spec/models/concerns/after_commit_queue_spec.rb

@@ -69,5 +69,60 @@ RSpec.describe AfterCommitQueue do
 
       expect(called).to be true
     end
+
+    context 'multiple databases - Ci::ApplicationRecord models' do
+      before do
+        skip_if_multiple_databases_not_setup
+
+        table_sql = <<~SQL
+          CREATE TABLE _test_ci_after_commit_queue (
+            id serial NOT NULL PRIMARY KEY);
+        SQL
+
+        ::Ci::ApplicationRecord.connection.execute(table_sql)
+      end
+
+      let(:ci_klass) do
+        Class.new(Ci::ApplicationRecord) do
+          self.table_name = '_test_ci_after_commit_queue'
+
+          include AfterCommitQueue
+
+          def self.name
+            'TestCiAfterCommitQueue'
+          end
+        end
+      end
+
+      let(:ci_record) { ci_klass.new }
+
+      it 'runs immediately if not within a transaction' do
+        called = false
+        test_proc = proc { called = true }
+
+        ci_record.run_after_commit_or_now(&test_proc)
+
+        expect(called).to be true
+      end
+
+      it 'runs after transaction has completed' do
+        called = false
+        test_proc = proc { called = true }
+
+        Ci::ApplicationRecord.transaction do
+          # Add this record to the current transaction so that after commit hooks
+          # are called
+          Ci::ApplicationRecord.connection.add_transaction_record(ci_record)
+
+          ci_record.run_after_commit_or_now(&test_proc)
+
+          ci_record.save!
+
+          expect(called).to be false
+        end
+
+        expect(called).to be true
+      end
+    end
   end
 end