When running Active Record MySQL test, this warning is printed in the
console:
warning: instance variable errno not initialized
It turns out that this is a warning from `mysql` gem in MySQL::Error
object. However, since the `mysql` gem is no longer maintained, and
there won't be a newer version, it make sense for us to just silence
this warning to make the output cleaner.
I’m renaming all instances of `use_transcational_fixtures` to
`use_transactional_tests` and “transactional fixtures” to
“transactional tests”.
I’m deprecating `use_transactional_fixtures=`. So anyone who is
explicitly setting this will get a warning telling them to use
`use_transactional_tests=` instead.
I’m maintaining backwards compatibility—both forms will work.
`use_transactional_tests` will check to see if
`use_transactional_fixtures` is set and use that, otherwise it will use
itself. But because `use_transactional_tests` is a class attribute
(created with `class_attribute`) this requires a little bit of hoop
jumping. The writer method that `class_attribute` generates defines a
new reader method that return the value being set. Which means we can’t
set the default of `true` using `use_transactional_tests=` as was done
previously because that won’t take into account anyone using
`use_transactional_fixtures`. Instead I defined the reader method
manually and it checks `use_transactional_fixtures`. If it was set then
it should be used, otherwise it should return the default, which is
`true`. If someone uses `use_transactional_tests=` then it will
overwrite the backwards-compatible method with whatever they set.
Follow-Up to https://github.com/rails/rails/pull/14348
Ensure that SQLCounter.clear_log is called after each test.
This is a step to prevent side effects when running tests. This will allow us to run them in random order.
