This module provides a class method called `each_batch` that can be used
to iterate tables in batches in a more efficient way compared to Rails'
`in_batches` method. This commit also includes a RuboCop cop to
blacklist the use of `in_batches` in favour of this new method.
This is allowed for existing instances so we don't end up 76 offenses
right away, but for new code one should _only_ use this if they _have_
to remove non database data. Even then it's usually better to do this in
a service class as this gives you more control over how to remove the
data (e.g. in bulk).
From the Ruby style guide:
# bad
class FooError < StandardError
end
# okish
class FooError < StandardError; end
# good
FooError = Class.new(StandardError)
This cop does that, but only for error classes (classes where the
superclass ends in 'Error'). We have empty controllers and models, which
are perfectly valid empty classes.
This adds a Rubocop rule to enforce the use of
add_concurrent_foreign_key instead of the regular add_foreign_key
method. This cop has been disabled for existing migrations so we don't
need to change those.
