Filter language to not display the current lang in the dropdown

No need to set a lang that is actually already set

app/views/shared/menu/_language_selector.html.haml

@@ -3,6 +3,6 @@
     %i.ofn-i_071-globe
     %span= t 'language_name'
   %ul.dropdown
-    - OpenFoodNetwork::I18nConfig.selectable_locales.each do |l|
+    - OpenFoodNetwork::I18nConfig.locale_options.each do |l|
       %li
         = link_to t('language_name', locale: l), main_app.locale_path(l.to_s)

lib/open_food_network/i18n_config.rb

@@ -5,6 +5,11 @@ module OpenFoodNetwork
   # Currently, language settings are read from the environment.
   # See: config/application.yml
   class I18nConfig
+    # Users don't need to select the already selected locale.
+    def self.locale_options
+      selectable_locales - [I18n.locale.to_s]
+    end
+
     # Locales that can be selected by users.
     def self.selectable_locales
       ENV["AVAILABLE_LOCALES"].andand.split(/[\s,]+/) || []

spec/features/consumer/multilingual_spec.rb

@@ -127,7 +127,7 @@ feature 'Multilingual', js: true do
 
         find('.language-switcher').click
         within '.language-switcher .dropdown' do
-          expect(page).to have_link I18n.t('language_name', locale: :en), href: '/locales/en'
+          expect(page).not_to have_link I18n.t('language_name', locale: :en), href: '/locales/en'
           expect(page).to have_link I18n.t('language_name', locale: :es, default: 'Language Name'),
                                     href: '/locales/es'