Extract method to get a user segment name

We're going to add geozones as user segments, so it's handy to have the
method in the UserSegments class.

We're also changing the `user_segment_emails` parameter name for
consistency and simplicity.

spec/lib/user_segments_spec.rb

@@ -5,6 +5,22 @@ describe UserSegments do
   let(:user2) { create(:user) }
   let(:user3) { create(:user) }
 
+  describe ".segment_name" do
+    it "returns a readable name of the segment" do
+      expect(UserSegments.segment_name("all_users")).to eq "All users"
+      expect(UserSegments.segment_name("administrators")).to eq "Administrators"
+      expect(UserSegments.segment_name("proposal_authors")).to eq "Proposal authors"
+    end
+
+    it "accepts symbols as parameters" do
+      expect(UserSegments.segment_name(:all_users)).to eq "All users"
+    end
+
+    it "returns nil for invalid segments" do
+      expect(UserSegments.segment_name("invalid")).to be nil
+    end
+  end
+
   describe ".all_users" do
     it "returns all active users enabled" do
       active_user = create(:user)

spec/system/admin/admin_notifications_spec.rb

@@ -215,15 +215,15 @@ describe "Admin Notifications", :admin do
   end
 
   scenario "Select list of users to send notification" do
-    UserSegments.segments.each do |user_segment|
-      segment_recipient = I18n.t("admin.segment_recipient.#{user_segment}")
+    UserSegments.segments.each do |segment|
+      segment_recipient = UserSegments.segment_name(segment)
 
       visit new_admin_admin_notification_path
 
       fill_in_admin_notification_form(segment_recipient: segment_recipient)
       click_button "Create notification"
 
-      expect(page).to have_content(I18n.t("admin.segment_recipient.#{user_segment}"))
+      expect(page).to have_content segment_recipient
     end
   end
 end

spec/system/admin/emails/newsletters_spec.rb

@@ -16,7 +16,7 @@ describe "Admin newsletter emails", :admin do
 
       expect(page).to have_link "Go back", href: admin_newsletters_path
       expect(page).to have_content "This is a subject"
-      expect(page).to have_content I18n.t("admin.segment_recipient.#{newsletter.segment_recipient}")
+      expect(page).to have_content "All users"
       expect(page).to have_content "no-reply@consul.dev"
       expect(page).to have_content "This is a body"
     end
@@ -40,10 +40,9 @@ describe "Admin newsletter emails", :admin do
       expect(page).to have_css(".newsletter", count: 3)
 
       newsletters.each do |newsletter|
-        segment_recipient = I18n.t("admin.segment_recipient.#{newsletter.segment_recipient}")
         within("#newsletter_#{newsletter.id}") do
           expect(page).to have_content newsletter.subject
-          expect(page).to have_content segment_recipient
+          expect(page).to have_content UserSegments.segment_name(newsletter.segment_recipient)
         end
       end
     end
@@ -162,13 +161,15 @@ describe "Admin newsletter emails", :admin do
   end
 
   scenario "Select list of users to send newsletter" do
-    UserSegments.segments.each do |user_segment|
+    UserSegments.segments.each do |segment|
+      segment_recipient = UserSegments.segment_name(segment)
+
       visit new_admin_newsletter_path
 
-      fill_in_newsletter_form(segment_recipient: I18n.t("admin.segment_recipient.#{user_segment}"))
+      fill_in_newsletter_form(segment_recipient: segment_recipient)
       click_button "Create Newsletter"
 
-      expect(page).to have_content(I18n.t("admin.segment_recipient.#{user_segment}"))
+      expect(page).to have_content segment_recipient
     end
   end
 end