Add spec to test taking over session values

spec/services/users/login_service_spec.rb

@@ -0,0 +1,79 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe ::Users::LoginService, type: :model do
+  let(:input_user) { FactoryBot.build_stubbed(:user) }
+  let(:controller) { double('ApplicationController') }
+  let(:session) { {} }
+
+  let(:instance) { described_class.new(controller: controller) }
+
+  subject { instance.call(input_user) }
+
+  describe 'session' do
+    context 'with an SSO provider' do
+      let(:sso_provider) do
+        {
+          name: 'saml',
+          retain_from_session: %i[foo bar]
+        }
+      end
+
+      before do
+        allow(controller)
+          .to(receive(:login_provider_for))
+          .and_return sso_provider
+
+        allow(controller)
+          .to(receive(:session))
+          .and_return session
+
+        allow(controller)
+          .to(receive(:reset_session)) do
+          session.clear
+        end
+      end
+
+      context 'if provider retains session values' do
+        let(:retained_values) { %i[foo bar] }
+
+        it 'retains present session values' do
+          session[:foo] = 'foo value'
+          session[:what] = 'should be cleared'
+
+          subject
+
+          expect(session[:foo]).to be_present
+          expect(session[:user_id]).to eq input_user.id
+        end
+      end
+    end
+  end
+end