Add active_language controller and cookie storage

spec/requests/active_language_spec.rb

@@ -0,0 +1,20 @@
+require 'rails_helper'
+
+RSpec.describe "ActiveLanguages", type: :request do
+
+  describe "POST :set_active_language" do
+    
+    it "should set the cookie" do
+      language = FactoryBot.create(:language)
+      post "/set_active_language/", params: { active_language_id: language.id }
+      expect(cookies[:active_language_id]).to_not be_nil
+    end
+
+    it "should not set the cookie if language does not exist" do
+      language = FactoryBot.create(:language)
+      id = language.id + 1
+      post "/set_active_language/", params: { active_language_id: id }
+      expect(response).to have_http_status(:unprocessable_entity)
+    end
+  end
+end

spec/requests/root_spec.rb

@@ -39,5 +39,12 @@ RSpec.describe "Root path", type: :request do
       get root_path
       expect(response.body).to include(user.username)
     end
+
+    it "should have a language drop-down" do
+      user = FactoryBot.create(:user)
+      sign_in user
+      get root_path
+      expect(response.body).to have_field("active_language_id")
+    end
   end
 end