Rails 6.1: Add Active Record Marshal forward compatibility tests (#893)

* add Active Record Marshal forward compatibility tests

* add changelog item

Author: mgrunberg

CHANGELOG.md

@@ -15,6 +15,7 @@
 - [#891](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/891) Add support for if_not_exists to indexes
 - [#892](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/892) Add support for if_exists on remove_column
 - [#883](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/885) Fix quoting of ActiveRecord::Relation::QueryAttribute and ActiveModel::Attributes
+- [#893](https://github.com/rails-sqlserver/activerecord-sqlserver-adapter/pull/893) Add Active Record Marshal forward compatibility tests
 
 #### Changed
 

test/cases/coerced_tests.rb

@@ -1656,3 +1656,14 @@ def test_annotate_is_sanitized_coerced
     end
   end
 end
+
+class MarshalSerializationTest < ActiveRecord::TestCase
+  private
+
+  def marshal_fixture_path(file_name)
+    File.expand_path(
+      "support/marshal_compatibility_fixtures/#{ActiveRecord::Base.connection.adapter_name}/#{file_name}.dump",
+      ARTest::SQLServer.test_root_sqlserver
+    )
+  end
+end