Merge pull request #3961 from nebulab/dont-check-env-for-mailer-previews

Don't hack into ActionMailer to add our mail previews path

core/lib/spree/core/engine.rb

@@ -55,18 +55,13 @@ class Engine < ::Rails::Engine
         end
       end
 
-      config.after_initialize do
-        # Load in mailer previews for apps to use in development.
-        # We need to make sure we call `Preview.all` before requiring our
-        # previews, otherwise any previews the app attempts to add need to be
-        # manually required.
-        if Rails.env.development? || Rails.env.test?
-          ActionMailer::Preview.all
+      # Load in mailer previews for apps to use in development.
+      initializer "spree.core.action_mailer.set_preview_path", after: "action_mailer.set_configs" do |app|
+        original_preview_path = app.config.action_mailer.preview_path
+        solidus_preview_path = Spree::Core::Engine.root.join 'lib/spree/mailer_previews'
 
-          Dir[root.join("lib/spree/mailer_previews/**/*_preview.rb")].each do |file|
-            require_dependency file
-          end
-        end
+        app.config.action_mailer.preview_path = "{#{original_preview_path},#{solidus_preview_path}}"
+        ActionMailer::Base.preview_path = app.config.action_mailer.preview_path
       end
     end
   end

core/lib/spree/testing_support/dummy_app.rb

@@ -64,6 +64,7 @@ class Application < ::Rails::Application
 
     config.action_mailer.delivery_job = "ActionMailer::MailDeliveryJob" if RAILS_6_OR_ABOVE
     config.action_mailer.preview_path = File.expand_path('dummy_app/mailer_previews', __dir__)
+    config.action_mailer.show_previews = true
     config.active_record.sqlite3.represent_boolean_as_integer = true unless RAILS_6_OR_ABOVE
 
     config.storage_path = Rails.root.join('tmp', 'storage')