1 files changed, 56 insertions, 0 deletions
diff --git a/spec/rails_autoload.rb b/spec/rails_autoload.rb
new file mode 100644
index 00000000000..d3518acf8b2
--- /dev/null
+++ b/spec/rails_autoload.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+# Mimics Rails autoloading with zeitwerk when used outside of Rails.
+# This is used in:
+# * fast_spec_helper
+# * scripts/setup-test-env
+
+require 'zeitwerk'
+require 'active_support/string_inquirer'
+
+module Rails
+  extend self
+
+  def root
+    Pathname.new(File.expand_path('..', __dir__))
+  end
+
+  def env
+    @_env ||= ActiveSupport::StringInquirer.new(ENV["RAILS_ENV"] || ENV["RACK_ENV"] || "test")
+  end
+
+  def autoloaders
+    @autoloaders ||= [
+      Zeitwerk::Loader.new.tap do |loader|
+        loader.inflector = _autoloader_inflector
+      end
+    ]
+  end
+
+  private
+
+  def _autoloader_inflector
+    # Try Rails 7 first.
+    require 'rails/autoloaders/inflector'
+
+    Rails::Autoloaders::Inflector
+  rescue LoadError
+    # Fallback to Rails 6.
+    require 'active_support/dependencies'
+    require 'active_support/dependencies/zeitwerk_integration'
+
+    ActiveSupport::Dependencies::ZeitwerkIntegration::Inflector
+  end
+end
+
+require_relative '../lib/gitlab'
+require_relative '../config/initializers/0_inject_enterprise_edition_module'
+require_relative '../config/initializers_before_autoloader/000_inflections'
+require_relative '../config/initializers_before_autoloader/004_zeitwerk'
+
+Rails.autoloaders.each do |autoloader|
+  autoloader.push_dir('lib')
+  autoloader.push_dir('ee/lib') if Gitlab.ee?
+  autoloader.push_dir('jh/lib') if Gitlab.jh?
+  autoloader.setup
+end