For the HashAlignment rule, we're using the default `key` style (keys
are aligned and values aren't) instead of the `table` style (both keys
and values are aligned) because, even if we used both in the
application, we used the `key` style a lot more. Furthermore, the
`table` style looks strange in places where there are both very long and
very short keys and sometimes we weren't even consistent with the
`table` style, aligning some keys without aligning other keys.
Ideally we could align hashes to "either key or table", so developers
can decide whether keeping the symmetry of the code is worth it in a
case-per-case basis, but Rubocop doesn't allow this option.
To get the heading where a user voted, we were relying on the
`balloted_heading_id` field.
Our guess is this was done so the total number of users is the same as
the sum of users who voted on a heading. That is, if 2000 people voted
just on the "All city" heading, 1000 voted just on the "North district"
heading, and 500 people voted on both, instead of showing "3500 people
voted in total, 2500 voted in all city, 1500 voted in north district",
we show something like "3500 people voted in total, 2250 voted in all
city, and 1250 voted in north district".
However, this approach has some disadvantages.
The first disadvantage is, the stats aren't correct. In the case above,
2500 voted on the "All city heading", so the statistics for this heading
don't show reality.
The second one is we weren't considering the last heading where users
voted inside the budget being displayed, but the last heading where
users voted, period. That means that, if all the people above voted on a
later budget, the stats for the budget above would become "3500 people
voted in total, 0 voted in all city, and 0 voted in north district".
That also means we were including headings from previous budgets in the
statistics for more recent budgets when people hadn't voted on the
recent ones.
So we're removing the `balloted_heading_id` since its data is lost once
people vote on a new budget. And, in order to show the right stats and
simplify the code, we're no longer trying to add votes just to one
heading when users vote on several headings.
Co-Authored-By: Julian Nicolas Herrero <microweb10@gmail.com>
With two concurrent requests, it's possible to create two ballot lines
when only one of them should be created.
The reason is the code validating the line is not thread safe:
```
if ballot.amount_available(investment.heading) < investment.price.to_i
errors.add(:money, "insufficient funds")
end
```
If the second request executes this code after the first request has
executed it but before the first request has saved the record to the
database, both records will pass this validation and both will be saved
to the database.
So we need to introduce a lock. Now when the second request tries to
lock the ballot, it finds it's already locked by the first request, and
will wait for the transaction of the first request to finish before
checking whether there are sufficient funds.
Note we need to disable transactions during the test; otherwise the
second thread will wait for the first one to finish.
Also note that we need to update a couple of tests because records are
reloaded when they're locked.
In one case, reloading the ballot causes `ballot.user` to be `nil`,
since the user is hidden. So we hide the user after creating all its
associated records (which is the scenario that would take place in real
life).
In the other case, reloading the ballot causes `ballot.user` to reload
as well. So we need to reload the user object used in the test too so it
gets the updates done on `ballot.user`.
I haven't been able to reproduce this behavior in a system test. The
following test works with Rails 5.0, but it stopped working when we
moved to system tests in commit 9427f014. After that commit, for reasons
I haven't been able to debug (reintroducing truncation with
DatabaseClaner didn't seem to affect this test, and neither did
increasing the number of threads in Puma), the two AJAX requests
executed here are no longer simultaneous; the second request waits for
the first one to finish.
scenario "Race conditions with simultaneous requests", :js do
allow_any_instance_of(Budget::Ballot::Line).to receive(:check_sufficient_funds) do |object|
allow(object).to receive(:check_sufficient_funds).and_call_original
object.check_sufficient_funds
sleep 0.3
end
["First", "Second"].each do |title|
create(:budget_investment, :selected,
heading: california,
price: california.price,
title: title
)
end
login_as(user)
visit budget_investments_path(budget, heading_id: california.id)
within(".budget-investment", text: "First") { click_link "Vote" }
within(".budget-investment", text: "Second") { click_link "Vote" }
expect(page).to have_link "Remove vote"
expect(Budget::Ballot::Line.count).to eq 1
end
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
Having exceptions is better than having silent bugs.
There are a few methods I've kept the same way they were.
The `RelatedContentScore#score_with_opposite` method is a bit peculiar:
it creates scores for both itself and the opposite related content,
which means the opposite related content will try to create the same
scores as well.
We've already got a test to check `Budget::Ballot#add_investment` when
creating a line fails ("Edge case voting a non-elegible investment").
Finally, the method `User#send_oauth_confirmation_instructions` doesn't
update the record when the email address isn't already present, leading
to the test "Try to register with the email of an already existing user,
when an unconfirmed email was provided by oauth" fo fail if we raise an
exception for an invalid user. That's because updating a user's email
doesn't update the database automatically, but instead a confirmation
email is sent.
There are also a few false positives for classes which don't have bang
methods (like the GraphQL classes) or destroying attachments.
For these reasons, I'm adding the rule with a "Refactor" severity,
meaning it's a rule we can break if necessary.
We're using `eq` and `match_array` in most places, but there were a few
places where we were still checking each element is included in the
array. This is a bit dangerous, because the array could have duplicate
elements, and we wouldn't detect them with `include`.
