Merge branch '202072-fix-flaky-examples' into 'master'

Sign-out current user when calling `sign_in` in tests and fix an example that only passes on retry

Closes #202072

See merge request gitlab-org/gitlab!24454

spec/controllers/groups_controller_spec.rb

@@ -96,7 +96,7 @@ describe GroupsController do
             User.where(id: [admin, owner, maintainer, developer, guest]).update_all(can_create_group: can_create_group_status)
           end
 
-          [:admin, :owner].each do |member_type|
+          [:admin, :owner, :maintainer].each do |member_type|
             context "and logged in as #{member_type.capitalize}" do
               it_behaves_like 'member with ability to create subgroups' do
                 let(:member) { send(member_type) }
@@ -104,7 +104,7 @@ describe GroupsController do
             end
           end
 
-          [:guest, :developer, :maintainer].each do |member_type|
+          [:guest, :developer].each do |member_type|
             context "and logged in as #{member_type.capitalize}" do
               it_behaves_like 'member without ability to create subgroups' do
                 let(:member) { send(member_type) }

spec/support/helpers/controller_helpers.rb

+# frozen_string_literal: true
+
+module ControllerHelpers
+  # It seems Devise::Test::ControllerHelpers#sign_in doesn't clear out the @current_user
+  # variable of the controller, hence it's not overwritten on retries.
+  # This should be fixed in Devise:
+  #   - https://github.com/heartcombo/devise/issues/5190
+  #   - https://github.com/heartcombo/devise/pull/5191
+  def sign_in(resource, deprecated = nil, scope: nil)
+    super
+
+    scope ||= Devise::Mapping.find_scope!(resource)
+
+    @controller.instance_variable_set(:"@current_#{scope}", nil)
+  end
+end
+
+Devise::Test::ControllerHelpers.prepend(ControllerHelpers)