Don't access the database in comment replies tests

As mentioned in commits like a586ba806, a7664ad81, 006128da5, b41fbfa52
and c480cdd91, accessing the database after starting the browser with
the `visit` method sometimes results in database corruption and failing
tests on our CI due to the process running the test accessing the
database after the process running the browser has started.

In this case, we're avoiding the usage of `user.subscriptions_token` and
`Comment.last`. In the future, we should probably simplify these tests
by moving most of the checks to a mailer test.

spec/support/common_actions/comments.rb

@@ -1,14 +1,14 @@
 module Comments
-  def reply_to(comment, replier: create(:user))
+  def reply_to(comment, with: "I like what you say", replier: create(:user))
     login_as(replier)
 
     visit polymorphic_path(comment.commentable)
 
     click_link "Reply"
     within "#js-comment-form-comment_#{comment.id}" do
-      fill_in "Leave your comment", with: "It will be done next week."
+      fill_in "Leave your comment", with: with
       click_button "Publish reply"
     end
-    expect(page).to have_content "It will be done next week."
+    expect(page).to have_content with
   end
 end

spec/system/emails_spec.rb

@@ -40,21 +40,25 @@ describe "Emails" do
   end
 
   context "Comment replies" do
-    let(:user) { create(:user, email_on_comment_reply: true) }
-    let(:debate) { create(:debate) }
+    let(:user) { create(:user, email_on_comment_reply: true, subscriptions_token: "commenter_token") }
+    let(:debate) { create(:debate, title: "Controversial topic") }
     let!(:comment) { create(:comment, commentable: debate, user: user) }
 
     scenario "Send email on comment reply" do
-      reply_to(comment)
+      reply_to(comment, with: "It will be done next week")
 
       email = open_last_email
-      expect(email).to have_subject("Someone has responded to your comment")
-      expect(email).to deliver_to(user)
-      expect(email).not_to have_body_text(debate_path(debate))
-      expect(email).to have_body_text(comment_path(Comment.last))
-      expect(email).to have_body_text("To unsubscribe from these emails, visit")
-      expect(email).to have_body_text(edit_subscriptions_path(token: user.subscriptions_token))
-      expect(email).to have_body_text('and uncheck "Notify me by email when someone replies to my comments"')
+      expect(email).to have_subject "Someone has responded to your comment"
+      expect(email).to deliver_to user
+      expect(email).not_to have_body_text debate_path(debate)
+      expect(email).to have_body_text "It will be done next week"
+      expect(email).to have_link "Controversial topic"
+      expect(email).to have_body_text "To unsubscribe from these emails, visit"
+      expect(email).to have_link "Notifications", href: edit_subscriptions_url(
+                                                          host: Mailer.default_url_options[:host],
+                                                          token: "commenter_token"
+                                                        )
+      expect(email).to have_body_text 'and uncheck "Notify me by email when someone replies to my comments"'
     end
 
     scenario "Do not send email about own replies to own comments" do
@@ -312,20 +316,23 @@ describe "Emails" do
 
   context "Polls" do
     scenario "Send email on poll comment reply" do
-      user = create(:user, email_on_comment_reply: true)
-      poll = create(:poll, author: create(:user))
+      user = create(:user, email_on_comment_reply: true, subscriptions_token: "user_token")
+      poll = create(:poll, author: create(:user), name: "Important questions")
       comment = create(:comment, commentable: poll, author: user)
 
       reply_to(comment)
 
       email = open_last_email
-      expect(email).to have_subject("Someone has responded to your comment")
-      expect(email).to deliver_to(user)
-      expect(email).not_to have_body_text(poll_path(poll))
-      expect(email).to have_body_text(comment_path(Comment.last))
-      expect(email).to have_body_text("To unsubscribe from these emails, visit")
-      expect(email).to have_body_text(edit_subscriptions_path(token: user.subscriptions_token))
-      expect(email).to have_body_text('and uncheck "Notify me by email when someone replies to my comments"')
+      expect(email).to have_subject "Someone has responded to your comment"
+      expect(email).to deliver_to user
+      expect(email).not_to have_body_text poll_path(poll)
+      expect(email).to have_body_text "Important questions"
+      expect(email).to have_body_text "To unsubscribe from these emails, visit"
+      expect(email).to have_link "Notifications", href: edit_subscriptions_url(
+                                                          host: Mailer.default_url_options[:host],
+                                                          token: "user_token"
+                                                        )
+      expect(email).to have_body_text 'and uncheck "Notify me by email when someone replies to my comments"'
     end
   end