rails--rails/guides/source/6_0_release_notes.md

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Ruby on Rails 6.0 Release Notes

Highlights in Rails 6.0:

• Action Mailbox
• Action Text
• Parallel Testing
• Action Cable Testing

These release notes cover only the major changes. To learn about various bug fixes and changes, please refer to the change logs or check out the list of commits in the main Rails repository on GitHub.

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Upgrading to Rails 6.0

If you're upgrading an existing application, it's a great idea to have good test coverage before going in. You should also first upgrade to Rails 5.2 in case you haven't and make sure your application still runs as expected before attempting an update to Rails 6.0. A list of things to watch out for when upgrading is available in the Upgrading Ruby on Rails guide.

Major Features

Action Mailbox

Pull Request

Action Mailbox allows you to route incoming emails to controller-like mailboxes. You can read more about Action Mailbox in the Action Mailbox Basics guide.

Action Text

Pull Request

Action Text brings rich text content and editing to Rails. It includes the Trix editor that handles everything from formatting to links to quotes to lists to embedded images and galleries. The rich text content generated by the Trix editor is saved in its own RichText model that's associated with any existing Active Record model in the application. Any embedded images (or other attachments) are automatically stored using Active Storage and associated with the included RichText model.

You can read more about Action Text in the Action Text Overview guide.

Parallel Testing

Pull Request

Parallel Testing allows you to parallelize your test suite. While forking processes is the default method, threading is supported as well. Running tests in parallel reduces the time it takes your entire test suite to run.

Action Cable Testing

Pull Request

Action Cable testing tools allow you to test your Action Cable functionality at any level: connections, channels, broadcasts.

Railties

Please refer to the Changelog for detailed changes.

Removals

• Remove deprecated after_bundle helper inside plugins templates. (Commit)

• Remove deprecated support to config.ru that uses the application class as argument of run. (Commit)

• Remove deprecated environment argument from the rails commands. (Commit)

• Remove deprecated capify! method in generators and templates. (Commit)

• Remove deprecated config.secret_token. (Commit)

Deprecations

• Deprecate passing Rack server name as a regular argument to rails server. (Pull Request)

• Deprecate support for using HOST environment to specify server IP. (Pull Request)

• Deprecate accessing hashes returned by config_for by non-symbol keys. (Pull Request)

Notable changes

• Add an explicit option --using or -u for specifying the server for the rails server command. (Pull Request)

• Add ability to see the output of rails routes in expanded format. (Pull Request)

• Run the seed database task using inline Active Job adapter. (Pull Request)

• Add a command rails db:system:change to change the database of the application. (Pull Request)

• Add rails test:channels command to test only Action Cable channels. (Pull Request)

• Introduce guard against DNS rebinding attacks. (Pull Request)

• Add ability to abort on failure while running generator commands. (Pull Request)

• Make Webpacker the default JavaScript compiler for Rails 6. (Pull Request)

• Add multiple database support for rails db:migrate:status command. (Pull Request)

• Add ability to use different migration paths from multiple databases in the generators. (Pull Request)

• Add support for multi environment credentials. (Pull Request)

• Make null_store as default cache store in test environment. (Pull Request)

Action Cable

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

• The ActionCable javascript package has been converted from CoffeeScript to ES2015, and we now publish the source code in the npm distribution.

  This allows ActionCable users to depend on the javascript source code rather than the compiled code, which can produce smaller javascript bundles.

  This change includes some breaking changes to optional parts of the ActionCable javascript API:

  • Configuration of the WebSocket adapter and logger adapter have been moved from properties of ActionCable to properties of ActionCable.adapters.

  • The ActionCable.startDebugging() and ActionCable.stopDebugging() methods have been removed and replaced with the property ActionCable.logger.enabled.

Action Pack

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

Action View

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

Action Mailer

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

Active Record

Please refer to the Changelog for detailed changes.

Removals

• Remove deprecated #set_state from the transaction object. (Commit)

• Remove deprecated #supports_statement_cache? from the database adapters. (Commit)

• Remove deprecated #insert_fixtures from the database adapters. (Commit)

• Remove deprecated ActiveRecord::ConnectionAdapters::SQLite3Adapter#valid_alter_table_type?. (Commit)

• Remove support for passing the column name to sum when a block is passed. (Commit)

• Remove support for passing the column name to count when a block is passed. (Commit)

• Remove support for delegation of missing methods in a relation to arel. (Commit)

• Remove support for delegating missing methods in a relation to private methods of the class. (Commit)

• Remove support for specifying a timestamp name for #cache_key. (Commit)

• Remove deprecated ActiveRecord::Migrator.migrations_path=. (Commit)

• Remove deprecated expand_hash_conditions_for_aggregates. (Commit)

Deprecations

• Deprecate mismatched case-sensitivity collation comparisons for uniqueness validator. (Commit)

• Deprecate using class level querying methods if the receiver scope has leaked. (Pull Request)

• Deprecate config.activerecord.sqlite3.represent_boolean_as_integer. (Commit)

• Deprecate passing migrations_paths to connection.assume_migrated_upto_version. (Commit)

• Deprecate ActiveRecord::Result#to_hash in favor of ActiveRecord::Result#to_a. (Commit)

• Deprecate methods in DatabaseLimits: column_name_length, table_name_length, columns_per_table, indexes_per_table, columns_per_multicolumn_index, sql_query_length, and joins_per_query. (Commit)

• Deprecate update_attributes/! in favor of update/!. (Commit)

Notable changes

• Bump the minimum sqlite3 version to 1.4. (Pull Request)

• Add rails db:prepare to create a database if it doesn't exist, and run its migrations. (Pull Request)

• Add after_save_commit callback as shortcut for after_commit :hook, on: [ :create, :update ]. (Pull Request)

• Add ActiveRecord::Relation#extract_associated for extracting associated records from a relation. (Pull Request)

• Add ActiveRecord::Relation#annotate for adding SQL comments to ActiveRecord::Relation queries. (Pull Request)

• Add support for setting Optimizer Hints on databases. (Pull Request)

• Add insert_all/insert_all!/upsert_all methods for doing bulk inserts. (Pull Request)

• Add rails db:seed:replant that truncates tables of each database for ther current environment and loads the seeds. (Pull Request)

• Add reselect method, which is a short-hand for unscope(:select).select(fields). (Pull Request)

• Add negative scopes for all enum values. (Pull Request)

• Add #destroy_by and #delete_by for conditional removals. (Pull Request)

• Add the ability to automatically switch database connections. (Pull Request)

• Add the ability to prevent writes to a database for the duration of a block. (Pull Request)

• Add an API for switching connections to support multiple databases. (Pull Request)

• Make timestamps with precision the default for migrations. (Pull Request)

• Support :size option to change text and blob size in MySQL. (Pull Request)

• Set both the foreign key and the foreign type columns to NULL for polymorphic associations on dependent: :nullify strategy. (Pull Request)

• Allow a permitted instance of ActionController::Parameters to be passed as an argument to ActiveRecord::Relation#exists?. (Pull Request)

• Add support in #where for endless ranges introduced in Ruby 2.6. (Pull Request)

• Make ROW_FORMAT=DYNAMIC a default create table option for MySQL. (Pull Request)

• Add the ability to disable scopes generated by ActiveRecord.enum. (Pull Request)

• Make implicit ordering configurable for a column. (Pull Request)

• Bump the minimum PostgreSQL version to 9.3, dropping support for 9.1 and 9.2. (Pull Request)

• Make the values of an enum frozen, raising an error when attempting to modify them. (Pull Request)

• Make the SQL of ActiveRecord::StatementInvalid errors its own error property and include SQL binds as a separate error property. (Pull Request)

• Add an :if_not_exists option to create_table. (Pull Request)

• Add support for multiple databases to rails db:schema:cache:dump and rails db:schema:cache:clear. (Pull Request)

• Add support for hash and url configs in database hash of ActiveRecord::Base.connected_to. (Pull Request)

• Add support for default expressions and expression indexes for MySQL. (Pull Request)

• Add an index option for change_table migration helpers. (Pull Request)

• Fix transaction reverting for migrations. Previously, commands inside of a transaction in a reverted migration ran uninverted. This change fixes that. (Pull Request)

• Allow ActiveRecord::Base.configurations= to be set with a symbolized hash. (Pull Request)

• Fix the counter cache to only update if the record is actually saved. (Pull Request)

• Add expression indexes support for the SQLite adapter. (Pull Request)

• Allow subclasses to redefine autosave callbacks for associated records. (Pull Request)

• Bump the minimum MySQL version to 5.5.8. (Pull Request)

• Use the utf8mb4 character set by default in MySQL. (Pull Request)

• Add the ability to filter out sensitive data in #inspect (Pull Request, Pull Request)

• Change ActiveRecord::Base.configurations to return an object instead of a hash. (Pull Request)

• Add database configuration to disable advisory locks. (Pull Request)

• Update SQLite3 adapter alter_table method to restore foreign keys. (Pull Request)

• Allow the :to_table option of remove_foreign_key to be invertible. (Pull Request)

• Fix default value for mysql time types with specified precision. (Pull Request)

• Fix the touch option to behave consistently with Persistence#touch method. (Pull Request)

• Raise an exception for duplicate column definitions in Migrations. (Pull Request)

• Bump the minimum SQLite version to 3.8. (Pull Request)

• Fix parent records to not get saved with duplicate children records. (Pull Request)

• Ensure Associations::CollectionAssociation#size and Associations::CollectionAssociation#empty? use loaded association ids if present. (Pull Request)

• Add support to preload associations of polymorphic associations when not all the records have the requested associations. (Commit)

• Add touch_all method to ActiveRecord::Relation. (Pull Request)

• Add ActiveRecord::Base.base_class? predicate. (Pull Request)

• Add custom prefix/suffix options to ActiveRecord::Store.store_accessor. (Pull Request)

• Add ActiveRecord::Base.create_or_find_by/! to deal with the SELECT/INSERT race condition in ActiveRecord::Base.find_or_create_by/! by leaning on unique constraints in the database. (Pull Request)

• Add Relation#pick as short-hand for single-value plucks. (Pull Request)

Active Storage

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

Active Model

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

• Add a configuration option to customize format of the ActiveModel::Errors#full_message. (Pull Request)

• Add support for configuring attribute name for has_secure_password. (Pull Request)

• Add #slice! method to ActiveModel::Errors. (Pull Request)

• Add ActiveModel::Errors#of_kind? to check presence of a specific error. (Pull Request)

Active Support

Please refer to the Changelog for detailed changes.

Removals

Deprecations

Notable changes

Active Job

Please refer to the Changelog for detailed changes.

Removals

• Remove support for Qu gem. (Pull Request)

Deprecations

Notable changes

• Add support for custom serializers for Active Job arguments. (Pull Request)

• Add support for executing Active Jobs in the timezone in which they were enqueued. (Pull Request)

• Allow passing multiple exceptions to retry_on/discard_on. (Commit)

• Allow calling assert_enqueued_with and assert_enqueued_email_with without a block. (Pull Request)

• Wrap the notifications for enqueue and enqueue_at in the around_enqueue callback instead of after_enqueue callback. (Pull Request)

• Allow calling perform_enqueued_jobs without a block. (Pull Request)

• Allow calling assert_performed_with without a block. (Pull Request)

• Add :queue option to job assertions and helpers. (Pull Request)

• Add hooks to Active Job around retries and discards. (Pull Request)

• Add a way to test for subset of arguments when performing jobs. (Pull Request)

• Include deserialized arguments in jobs returned by Active Job test helpers. (Pull Request)

• Allow Active Job assertion helpers to accept Proc for only keyword. (Pull Request)

• Drop microseconds and nanoseconds from the job arguments in assertion helpers. (Pull Request)

Ruby on Rails Guides

Please refer to the Changelog for detailed changes.

Notable changes

Credits

See the full list of contributors to Rails for the many people who spent many hours making Rails, the stable and robust framework it is. Kudos to all of them.