Test env: fix ActionMailer preview_paths FrozenError and require fast_sqlite early for sqlite3 v2

Author: elia

core/lib/spree/testing_support/dummy_app.rb

@@ -3,6 +3,14 @@
 ENV['RAILS_ENV'] = 'test'
 ENV['DISABLE_DATABASE_ENVIRONMENT_CHECK'] = '1'
 
+# Ensure sqlite3 v2 is supported when running with the default sqlite adapter.
+# The `fast_sqlite` gem relaxes ActiveRecord's sqlite3 version constraints.
+begin
+  require 'fast_sqlite'
+rescue LoadError
+  # Gem not available, skip.
+end
+
 require 'rails'
 require 'active_record/railtie'
 require 'action_controller/railtie'
@@ -106,7 +114,10 @@ class Application < ::Rails::Application
 
     # Set the preview path within the dummy app:
     if ActionMailer::Base.respond_to? :preview_paths # Rails 7.1+
-      config.action_mailer.preview_paths << File.expand_path('dummy_app/mailer_previews', __dir__)
+      # Some Rails versions return a frozen array here; assign a new array
+      # to avoid FrozenError when augmenting the paths.
+      existing = Array(config.action_mailer.preview_paths)
+      config.action_mailer.preview_paths = existing + [File.expand_path('dummy_app/mailer_previews', __dir__)]
     else
       config.action_mailer.preview_path = File.expand_path('dummy_app/mailer_previews', __dir__)
     end

docker-compose.yml

@@ -1,4 +1,4 @@
-version: '3.7'
+version: "3.7"
 
 services:
   mysql:
@@ -18,12 +18,12 @@ services:
       - postgres:/var/lib/postgresql/data:cached
 
   app:
-    shm_size: '512mb'
+    shm_size: "512mb"
     build:
       context: .dockerdev
       dockerfile: Dockerfile
       args:
-        RUBY_VERSION: "3.1"
+        RUBY_VERSION: "3.4.6"
         PG_VERSION: 13
         NODE_VERSION: 20
         MYSQL_VERSION: "8.0"