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.
These tests don't use the browser to send emails since commit e21588ec1.
However, note that this commit actually actually decreased our test
coverage somehow; since then, we're no longer testing whether we send an
email to the author after clicking the "Publish comment" button. We
might need to add a test for this in the `spec/system/comments_spec.rb`
file... but that's a story for another time.
Note we need to stub the `deliver_later` method; otherwise,
`open_last_email` would raise an exception since no email would have
been delivered.
We're moving them now because these tests use the `open_last_email`
method, and we're looking for places where using this method might
result in a flaky test when used inside a system test.
We take the comment as a parameter instead of the user, since usually
people reply to comments and not to users.
We also remove one database query after the browser has started, since
we can use `debate_path(debate)`. It's also more clear why we're using
`debate_path` in the test; before these changes, we had to enter the
`reply_to` method to realize that we were replying on a debate.
