Note that, when taking votes from an erased user, since poll answers
don't belong to poll voters, we were not migrating them in the
`take_votes_from` method (and we aren't migrating them now either).
This call was added in commit 81f65f1ac, and the test for its need was
added in commit cb1542874. However, both the test and the helper method
relying on the `touch` call were removed in commit f90d0d9c4.
We were checking we didn't have more votes than allowed in the case of
questions with multiple answers, but we weren't checking it in the case
of questions with a single answer. This made it possible to create more
than one answer to the same question. This could happen because the
method `find_or_initialize_user_answer` might initialize two answers in
different threads, due to a race condition.
Back in commit 36e452437, we wrote:
> The `reload` method added to max_votes validation is needed because
> the author gets here with some changes because of the around_action
> `switch_locale`, which adds some changes to the current user record
> and therefore, the lock method raises an exception when trying to lock
> it requiring us to save or discard those record changes.
This happened when `current_user` didn't have a locale stored in the
database and the `current_locale` method returned the default locale.
And the test "Poll Votation Type Multiple answers" would indeed fail if
we removed the `reload` method. However, we can remove the need to
reload the record by avoiding the mentioned changes on the current user
record.
So we're changing the `User#locale` method so it doesn't modify the user
record.
The `reload` method added to max_votes validation is needed because the
author gets here with some changes because of the around_action
`switch_locale`, which adds some changes to the current user record and
therefore, the lock method raises an exception when trying to lock it
requiring us to save or discard those record changes.
In case we receive consecutive requests we are locking the poll author record
until the first request transaction ends, so the author answers count during
subsequent requests validations is up to date.
Up until now, we were assuming the voter was valid, but were not raising
an exception if it wasn't. And in the user interface everything seemed
to be working properly.
We were having this issue when skipping verification, when there could
be voters without a document number, which would be considered invalid.
Raising an exception when failing to save the voter and making sure the
answer and the voter are saved inside a transaction solves the problem.
Not doing so has a few gotchas when working with relations, particularly
with records which are not stored in the database.
I'm excluding the related content file because it's got a very peculiar
relationship with itself: the `has_one :opposite_related_content` has no
inverse; the relation itself is its inverse. It's a false positive since
the inverse condition is true:
```
content.opposite_related_content.opposite_related_content.object_id ==
content.object_id
```
Usually when we specify a `belongs_to` relations, we also specify its
equivalent `has_many`. That allows us to write, for example:
`topic.user.topics`.
We were very inconsistent regarding these rules.
Personally I prefer no empty lines around blocks, clases, etc... as
recommended by the Ruby style guide [1], and they're the default values
in rubocop, so those are the settings I'm applying.
The exception is the `private` access modifier, since we were leaving
empty lines around it most of the time. That's the default rubocop rule
as well. Personally I don't have a strong preference about this one.
[1] https://rubystyle.guide/#empty-lines-around-bodies
