Ensure the admin locale is only set by available locales

The available locales need to be Alchemy locales, not all locales
available to the I18n gem.

lib/alchemy/admin/locale.rb

@@ -41,7 +41,7 @@ def locale_change_needed?
       #
       def available_locale
         locales = [params[:admin_locale], locale_from_user, locale_from_browser].compact.map(&:to_sym)
-        locales.detect { |locale| ::I18n.available_locales.include?(locale) }
+        locales.detect { |locale| Alchemy::I18n.available_locales.include?(locale) }
       end
 
       # Try to get the locale from user settings.

spec/dummy/config/locales/alchemy.en.yml

@@ -0,0 +1,26 @@
+en:
+  alchemy:
+    element_names:
+      gallery_picture: Gallery picture
+    content_names:
+      essence_boolean: EssenceBoolean
+      essence_date: EssenceDate
+      essence_file: EssenceFile
+      essence_html: EssenceHtml
+      essence_link: EssenceLink
+      essence_picture: EssencePicture
+      essence_richtext: EssenceRichtext
+      essence_select: EssenceSelect
+      essence_text: EssenceText
+    element_hints:
+      all_you_can_eat: This element shows all content types (Essences) and settings of an Element Alchemy comes with in a default installation.
+    content_hints:
+      essence_boolean: This content type (Essence) represents a simple true/false value
+      essence_date: This content type (Essence) represents a date value
+      essence_file: This content type (Essence) represents a downloadable file
+      essence_html: This content type (Essence) represents raw HTML output
+      essence_link: This content type (Essence) represents a link
+      essence_picture: This content type (Essence) represents a picture
+      essence_richtext: This content type (Essence) represents richtext
+      essence_select: This content type (Essence) represents values the editor can choose from
+      essence_text: This content type (Essence) represents a simple line of text

spec/dummy/config/locales/alchemy.kl.yml

@@ -0,0 +1,3 @@
+kl:
+  alchemy:
+    welcome_back_note: majQa' Dub

spec/dummy/config/locales/en.yml

@@ -1,30 +1,4 @@
 en:
-  alchemy:
-    element_names:
-      gallery_picture: Gallery picture
-    content_names:
-      essence_boolean: EssenceBoolean
-      essence_date: EssenceDate
-      essence_file: EssenceFile
-      essence_html: EssenceHtml
-      essence_link: EssenceLink
-      essence_picture: EssencePicture
-      essence_richtext: EssenceRichtext
-      essence_select: EssenceSelect
-      essence_text: EssenceText
-    element_hints:
-      all_you_can_eat: This element shows all content types (Essences) and settings of an Element Alchemy comes with in a default installation.
-    content_hints:
-      essence_boolean: This content type (Essence) represents a simple true/false value
-      essence_date: This content type (Essence) represents a date value
-      essence_file: This content type (Essence) represents a downloadable file
-      essence_html: This content type (Essence) represents raw HTML output
-      essence_link: This content type (Essence) represents a link
-      essence_picture: This content type (Essence) represents a picture
-      essence_richtext: This content type (Essence) represents richtext
-      essence_select: This content type (Essence) represents values the editor can choose from
-      essence_text: This content type (Essence) represents a simple line of text
-
   activerecord:
     models:
       event:

spec/features/admin/locale_select_feature_spec.rb

@@ -4,6 +4,7 @@
 
 RSpec.describe 'Locale select', type: :system do
   let(:a_page) { create(:alchemy_page, :public) }
+
   before do
     allow(Alchemy::I18n).to receive(:translation_files).and_return ['alchemy.kl.yml', 'alchemy.jp.yml', 'alchemy.cz.yml']
     authorize_user(:as_admin)
@@ -19,9 +20,29 @@
       allow(Alchemy::I18n).to receive(:available_locales).and_return [:jp, :cz]
     end
 
-    it "provides only that locales" do
+    it "provides only these locales" do
       visit admin_dashboard_path
       expect(page).to have_select('change_locale', options: ['Jp', 'Cz'])
     end
   end
+
+  describe 'user selects locale' do
+    context 'that is available' do
+      before do
+        allow(Alchemy::I18n).to receive(:available_locales).and_return [:kl]
+      end
+
+      it 'switches the locale' do
+        visit admin_dashboard_path(admin_locale: 'kl')
+        expect(page).to have_content("majQa' Dub")
+      end
+    end
+
+    context 'that is not available' do
+      it 'does not switch the locale' do
+        visit admin_dashboard_path(admin_locale: 'de')
+        expect(page).to have_content("Welcome back")
+      end
+    end
+  end
 end