Broken tests after upgrading to Rails 6.1

[OndrejKu]

If I run the test suite by using rspec, I'm getting everything green, but when I use parallel_spec, I'm getting random errors.

In my test setup, I'm using database cleaner and transactional fixtures. After running bisect I was able to identify tests that are failing more precisely. The main issue happens after I added to my database configuration reader and replicas. The transaction on test side of things has all the data, but when I access the application side, there are no data. This doesn't happen on every file. For example now I have 2091 test cases, but only 7 of them are random failures.

I went back to the database settings and change the code to following:

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  connects_to database: { writing: :primary, reading: :primary_replica } unless Rails.env.test?
  connects_to database: { writing: :primary, reading: :primary } if Rails.env.test?
end

But this didn't help as I expected. Could this be a parallel_spec bug or Rails bug or am I doing something wrong?

[grosser]

• database cleaner should not be needed when using transactional fixtures ... so try removing to simplify setup
• run with --verbose to get a printout of the the files parallel_rspec runs and run them manually ... that should reproduce the issue and you can bisect from there