Kasper joins Rails core!

That's right Kasper gets himself a cartoon face!

Kasper has helped make countless changes and helped others make them as well.

He's continued to making substantial, individual contributions, like the new partial collection caching scheme, wildcard template dependencies, and big improvements to the test runner.

This Week's Rails Contributors

This week saw contributions from 30 fabulous people. 2 of those had a commit merged into Rails for the very first time.

A big thank you to you all! ❤️ If you fancy seeing yourself up there next week, why not take a peek at the list of current issues? Improvements to the documentation can also be a great place to start!

2x performance boost for String#blank? in Ruby 2.4!

String#blank? now uses Regex#match? following the backwards compatible addition of Regex#match? that was introduced.

This helps to get upto 2x the performance with new Regex improvements on Ruby 2.4!

Introduce assert_changes and assert_no_changes

ActiveSupport::TestCase was augmented to complement assert_difference with a more more general usage.

With this handy comparison, we can now do something like-

user = User.start_registration
assert_changes 'user.token', from: nil, to: /\w{​32}​/ do
  user.finish_registration
end

to encapsulate the state changes, before and after an operation.

Bring back support for callable cache key when rendering collection

Support for custom callable cache key was added back to view caching. This allows us to do something like

<%= render partial: 'projects/project', collection: @projects, cached: -> project {​ [ project, current_user ] }​ %>

and pass a key based on a callable block, which allows us to depend on cache's and cache expiration based on result of the call. In the above case, the cache will be expired with changes to project and current_user objects.

Add exists? and update_all to CollectionProxy to respect an association scope

This change added exists? and update_all to CollectionProxy to respect an association scope.

This was causing issues in newest version of Rails whenever update_all or exists? were called on a collection object like user.references.update_all(...).

Fix bug in ActiveRecord TimeZoneConverter#set_time_zone_without_conversion

Before this change, multi-parameter attributes conversion with invalid params caused issue, when AR's time_zone_aware_attributes was enabled, since that caused an invalid conversion. 

The new change, now tries conversion only when a valid value is available for safe-conversion.

Fix calling merge method as the first occurrence in a scope

Previously calling merge as the first method to build up a scope used to lead to errors-

scope :unsafe_chaining, -> {​ merge(Comment.newest) }​ #=> NoMethodError:

This change now allows us to overcome this and build up scopes like-

scope :chaining, ->{​merge(Comment.newest).joins(:comments) }​ # => OK

Allow MessageEncryptor to take advantage of authenticated encryption modes

This change allow MessageEncryptor to now support authenticated encryption modes.

AEAD modes like aes-256-gcm provide both confidentiality and data authenticity, eliminating the need to use MessageVerifier to check if the encrypted data has been tampered with. This speeds up encryption/decryption and results in shorter cipher text.

Setup default session store internally, and no longer through an initializer

This change removes creation of the config/initializers/session_store.rb to define session store via initializer and sets up default session store internally.

By default the session store will be set to cookie store with application name as session key.