Clear current language when switching sites

app/controllers/concerns/alchemy/admin/current_language.rb

@@ -6,11 +6,21 @@ module CurrentLanguage
       extend ActiveSupport::Concern
 
       included do
+        # This needs to happen before BaseController#current_alchemy_site sets the session value.
+        prepend_before_action :clear_current_language_from_session, if: :switching_site?, only: :index
         before_action :load_current_language
       end
 
       private
 
+      def switching_site?
+        params[:site_id].present? && (params[:site_id] != session[:alchemy_site_id]&.to_s)
+      end
+
+      def clear_current_language_from_session
+        session.delete(:alchemy_language_id)
+      end
+
       def load_current_language
         @current_language = if session[:alchemy_language_id].present?
           set_alchemy_language(session[:alchemy_language_id])

lib/alchemy/test_support/current_language_shared_examples.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+RSpec.shared_examples_for "a controller that loads current language" do |args|
+  context "when session has current language id key" do
+    let!(:site_1) { create(:alchemy_site) }
+    let!(:site_1_default_language) { create :alchemy_language, site: site_1, default: true }
+    let!(:another_site_1_language) { create :alchemy_language, site: site_1, code: :de }
+    let(:site_2) { create :alchemy_site, host: "another.host", languages: [build(:alchemy_language, code: :en), build(:alchemy_language, code: :de)] }
+
+    context "on index action" do
+      context "when switching the current site" do
+        before do
+          session[:alchemy_site_id] = site_1.id
+          session[:alchemy_language_id] = another_site_1_language.id
+        end
+
+        it "sets @current_language to the new site default language" do
+          get :index, params: {site_id: site_2.id}
+          expect(assigns(:current_language)).to eq site_2.default_language
+        end
+      end
+
+      context "when no language to set" do
+        it "shows flash warning with redirect" do
+          Alchemy::Language.destroy_all
+          get :index, params: {site_id: site_1.id}
+          expect(flash[:warning]).to eq Alchemy.t("Please create a language first.")
+          expect(response).to redirect_to admin_languages_path
+        end
+      end
+    end
+  end
+end

spec/controllers/alchemy/admin/layoutpages_controller_spec.rb

@@ -10,6 +10,8 @@ module Alchemy
       authorize_user(:as_admin)
     end
 
+    it_behaves_like "a controller that loads current language"
+
     describe "#index" do
       context "with no language present" do
         it "redirects to the languages admin" do

spec/controllers/alchemy/admin/nodes_controller_spec.rb

@@ -10,6 +10,8 @@ module Alchemy
       authorize_user(:as_admin)
     end
 
+    it_behaves_like "a controller that loads current language"
+
     describe "#index" do
       context "if no language is present" do
         it "redirects to the language admin" do

spec/controllers/alchemy/admin/pages_controller_spec.rb

@@ -10,6 +10,8 @@
     authorize_user(:as_admin)
   end
 
+  it_behaves_like "a controller that loads current language"
+
   describe "#index" do
     let!(:page) { create(:alchemy_page) }
 

spec/rails_helper.rb

@@ -31,6 +31,7 @@
 require "alchemy/test_support/shared_contexts"
 require "alchemy/test_support/shared_link_tab_examples"
 require "alchemy/test_support/shared_uploader_examples"
+require "alchemy/test_support/current_language_shared_examples"
 
 require_relative "support/calculation_examples"
 require_relative "support/hint_examples"