This guide covers the process of migrating an old Spree 2/3 extension to Spree 4.
Zeitwerk is the new default code autoloader in Rails 6.
This doesn’t work well with the old approach to decorators (files that name ends with decorator.rb, eg.
app/models/spree/order_decorator.rb) using class_eval.
Example of an old decorator:
Spree::Order.class_eval do has_many :new_custom_model def some_method # ... end end
the same decorator in the new notation:
module YourExtensionName::OrderDecorator def self.prepended(base) base.has_many :new_custom_model end def some_method # ... end end ::Spree::Order.prepend(YourExtensionName::OrderDecorator)
You can always find up-to-date Travis CI config here: https://github.com/spree/spree/blob/master/cmd/lib/spree_cmd/templates/extension/travis.yml For the rationale of the changes please look at the blame view: https://github.com/spree/spree/blame/master/cmd/lib/spree_cmd/templates/extension/travis.yml
You can always find up-to-date Appraisals config here: https://github.com/spree/spree/blob/master/cmd/lib/spree_cmd/templates/extension/Appraisals
For the rationale of the changes please look at the blame view: https://github.com/spree/spree/blame/master/cmd/lib/spree_cmd/templates/extension/Appraisals
After each change please remember to re-generate gemfiles by running:
bundle exec appraisal generate --travis
Some Extensions still use Deface overrides to add some UI features, mainly in the admin panel. Deface isn’t recommended. If you can use other methods. Eg. If your extension adds a link to the Admin Panel menu you can do it this way https://guides.spreecommerce.org/developer/customization/view.html#adding-new-links-to-the-admin-panel-menu
If you’re stuck on Deface please remember to prepare versioned overrides for both Spree 3.x and 4.x, eg. https://github.com/spree-contrib/spree_static_content/commit/e4b9e4900024235158d0ec1a48a100b4732348ef
Spree 4 uses Bootstrap 4 and many partials and HTML structure changed compared to Spree 3.x.
Also - remember to add deface gem to gemspec as deface itself was removed as a dependency of Spree. eg. https://github.com/spree/spree_auth_devise/commit/d729689ca87d8586e541ffcc865ef1e0a5a79fe4
Replace all development dependencies with:
spec_helper.rb contents with: