Migrating Rails cookies to the new JSON serializer

How to move from Marshal to the new Rails 7 default JSON serializer.I was recently upgrading Phrase to Rails 7. Big upgrades like that are usually being done with the most minimal changes, and this one wasn’t an exception. However, every major and minor version of Rails brings some new defaults that can accumulate over time, leaving you with some debt to pay.Today I want to talk about the JSON serializer for cookies that became the default starting with Rails 7.0.