Fix evaluation comment email on system emails

Currently with both seeds and dev_seeds, not only was this email not
displayed from the system emails section, but it also caused an error in
the application.

@email_to had an empty value and in the view we tried to access
@email_to.name which caused the error. We kept the same logic but
added the current_user to make sure it always has a valid value. We add
the current_user because the current_user is always present in this controller..

app/controllers/admin/system_emails_controller.rb

@@ -104,7 +104,7 @@ class Admin::SystemEmailsController < Admin::BaseController
       comment = Comment.where(commentable_type: "Budget::Investment").last
       if comment
         @email = EvaluationCommentEmail.new(comment)
-        @email_to = @email.to.first
+        @email_to = @email.to.first || current_user
       else
         redirect_to admin_system_emails_path,
                     alert: t("admin.system_emails.alert.no_evaluation_comments")

spec/system/admin/system_emails_spec.rb

@@ -251,25 +251,36 @@ describe "System Emails" do
       expect(page).to have_content "Some example data is needed in order to preview the email."
     end
 
-    scenario "#evaluation_comment" do
-      admin = create(:administrator, user: create(:user, username: "Baby Doe"))
-      investment = create(:budget_investment,
-        title: "Cleaner city",
-        heading: heading,
-        author: user,
-        administrator: admin)
-      comment = create(:comment, :valuation, commentable: investment)
+    describe "#evaluation_comment" do
+      scenario "render correctly evaluaton comment mailer with valuator as a sample user" do
+        admin = create(:administrator, user: create(:user, username: "Baby Doe"))
+        investment = create(:budget_investment,
+          title: "Cleaner city",
+          heading: heading,
+          author: user,
+          administrator: admin)
+        comment = create(:comment, :valuation, commentable: investment)
 
-      visit admin_system_email_view_path("evaluation_comment")
+        visit admin_system_email_view_path("evaluation_comment")
 
-      expect(page).to have_content "New evaluation comment for Cleaner city"
-      expect(page).to have_content "Hi #{admin.name}"
-      expect(page).to have_content "There is a new evaluation comment from #{comment.user.name} "\
-                                   "to the budget investment Cleaner city"
-      expect(page).to have_content comment.body
+        expect(page).to have_content "New evaluation comment for Cleaner city"
+        expect(page).to have_content "Hi #{admin.name}"
+        expect(page).to have_content "There is a new evaluation comment from #{comment.user.name} "\
+                                     "to the budget investment Cleaner city"
+        expect(page).to have_content comment.body
 
-      expect(page).to have_link "Cleaner city",
-        href: admin_budget_budget_investment_url(investment.budget, investment, anchor: "comments", host: app_host)
+        expect(page).to have_link "Cleaner city",
+          href: admin_budget_budget_investment_url(investment.budget, investment, anchor: "comments", host: app_host)
+      end
+
+      scenario "uses a current_user as a sample user for sample regular comments" do
+        create(:budget_investment_comment, body: "This is a sample comment")
+
+        visit admin_system_email_view_path("evaluation_comment")
+
+        expect(page).to have_content "This is a sample comment"
+        expect(page).to have_content admin.name
+      end
     end
   end