Refine AR to enchant an ability to lease a connection when it cannot

lib/database_rewinder/cleaner.rb

@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 
+require_relative 'lease_connection_compat'
 require_relative 'multiple_statements_executor'
 
+using DatabaseRewinder::LeaseConnectionCompat
 using DatabaseRewinder::MultipleStatementsExecutor
 
 module DatabaseRewinder

lib/database_rewinder/lease_connection_compat.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module DatabaseRewinder
+  module LeaseConnectionCompat
+    # Make old AR compatible with AR >= 7.2 by defining `lease_connection`
+    unless ActiveRecord::ConnectionAdapters::ConnectionPool.instance_methods.include? :lease_connection
+      refine ActiveRecord::ConnectionAdapters::ConnectionPool do
+        def lease_connection
+          connection
+        end
+      end
+    end
+  end
+end

test/fake_app.rb

@@ -3,6 +3,9 @@
 ENV['DB'] ||= 'sqlite3'
 require 'active_record/railtie'
 
+require_relative '../lib/database_rewinder/lease_connection_compat'
+using DatabaseRewinder::LeaseConnectionCompat
+
 module DatabaseRewinderTestApp
   Application = Class.new(Rails::Application) do
     # Rais.root