Rails has added support in Action Cable to unsubscribe from specific streamRails adds ActionCable::Channel#stop_stream_from and ActionCable::Channel#stop_stream_for methods to allow user to unsubscribe from specific stream
Rails adds round_mode parameter support to number helpersRails has added :round_mode parameter support to number helpers
Ruby 2.7 - Setting $ special variables to non-nil value is now warnedIn Ruby 2.7, setting special variable $, $; $/ $\ to non-nil values will now show a deprecated warning
Eager loading Active Storage models to avoid N+1 issuesRemoving N+1 queries when we access the Active Storage attachments associated with an ActiveRecord model.
Rails adds jitter to ActiveJob::Exceptions.retry_onRails adds jitter to ActiveJob::Exceptions.retry_on to cater to thundering herd effect
Ruby Hash#transform_keys now accepts a hash that maps existing keys to new keysRuby Hash#transform_keys now also accepts a hash that maps the existing hash keys to new keys
Rails has added strict loading mode to prevent lazy loadingRails has added strict loading mode to prevent lazy loading of associations and help avoid N + 1 queries
Rails adds config rake_eager_loadRails has added the option to eager load all the registered name spaces in rake tasks.
Rails has added support for automatic database connection switching from primary to the replicaRails has added support for automatic database connection switching from primary to the replica
Ruby 2.7 removes taint checking mechanismRuby 2.7 access and setting of $SAFE is now always warned. $SAFE will become a normal global variable in Ruby 3.0