Fix: uninitialized constant User

In the test setting Test (MONGOID, 3.1, mongoid_73.gemfile)

got this error:
SimpleCov failed with exit 1/home/runner/work/pluck_all/pluck_all/test/mongoid/support/seeds.rb:2:in `<top (required)>': uninitialized constant User (NameError)

gemfiles/mongoid_73.gemfile

@@ -4,6 +4,11 @@ source 'https://rubygems.org'
 
 gem 'mongoid', '~> 7.3.3'
 
+# We need zeitwerk for autoloading in Rails 7
+# But zeitwerk required ruby >= 2.4.4, we cannot test it in ruby 2.3
+# So we lock the version below 7
+gem 'activesupport', '< 7'
+
 group :test do
   gem 'simplecov', '< 0.18'
 end

test/mongoid/support/seeds.rb

@@ -1,4 +1,8 @@
 # frozen_string_literal: true
+
+require 'rails_compatibility/setup_autoload_paths'
+RailsCompatibility.setup_autoload_paths [File.expand_path('../models/', __FILE__)]
+
 User.delete_all
 User.create(name: 'Pearl Shi', age: 18)
 User.create(name: 'Rumble Huang', age: 20)