DEPRECATION WARNING: Rails.application.secrets is deprecated in favor of Rails.application.credentials Rails 7.1 and Devise

DEPRECATION WARNING: Rails.application.secrets is deprecated in favor of Rails.application.credentials

I recently upgraded to Rails 7.1 for my project, kidcarekit (a daycare management Saas) and upon running my tests, discovered a dreaded DEPRECATION WARNING. Well, at least we caught it before 7.2 was released!

Being relatively new to rails, I wasn't immediately clear how to update my project to use the new Rails.application.credentials instead of secrets. My application.rb file looked like this, and the error pointed at Bundler.require(*Rails.groups)

require_relative "boot"

require "rails/all"

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module Kidcarekit
...	

After some digging it looks like this was due to the Devise gem having a SecretKeyFinder that looked like this:

# frozen_string_literal: true

module Devise
  class SecretKeyFinder
    def initialize(application)
      @application = application
    end

    def find
      if @application.respond_to?(:credentials) && key_exists?(@application.credentials)
        @application.credentials.secret_key_base
      elsif @application.respond_to?(:secrets) && key_exists?(@application.secrets)
        @application.secrets.secret_key_base
      elsif @application.config.respond_to?(:secret_key_base) && key_exists?(@application.config)
        @application.config.secret_key_base
      elsif @application.respond_to?(:secret_key_base) && key_exists?(@application)
        @application.secret_key_base
      end
    end

    private

    def key_exists?(object)
      object.secret_key_base.present?
    end
  end
end

The FIX - I am able to mitigate the warning by implementing a Devise-specific secret key in devise.rb, but I'd like to keep it using the secret_key_base. So, in light of Rails 7.1 just being release yesterday, I've decided to wait for Devise to catch up!