Part I.

• 01. Add drop_enum command for Postgres
• 02. Support multiple preview paths for mailers
• 03. error_highlight gem to locate columns with errors
• 04. routes --grep to filter routes by paths
• 05. ActiveRecord::QueryMethods#select accepts a hash
• 06. Pass options accessor to Cache#fetch block
• 07. Add :locals to Action View rendering instrumentation
• 08. Rails.error.report now marks errors as reported
• 09. ActionController::Parameters#exclude? added
• 10. Allow passing classes to dom_id
• 11. Add the ability to set the tags_format for QueryLogs
• 12. Facilitate the use of any regular ERB in database.yml
• 13. Add column information inside ERB templates

If you landed here through a search engine or a referral link, this is the second part of a three-part blog post series of features coming to Rails 7.1. Please see the intro section of An Overview Of Rails 7.1 Features. Part I for some context.

I encourage you to scroll down and subscribe to my newsletter for Ruby and Rails goodies if you’d like to stay up to date on developments or tips.

On to business.

01. Add drop_enum command for Postgres.

Rails had create_enum for Postgres without a matching drop_enum. This pull request added drop_enum while another pull request made drop_enum reversible. The latter pull request made it possible so that if the if_exists: true option is provided, the enum is dropped only if it exists. Otherwise, if the enum doesn’t exist, an ActiveRecord::IrreversibleMigration error is raised.

02. Support multiple preview paths for mailers.

The changes in this pull request make it possible to preview emails from engines, it does so by deprecating config.action_mailer.preview_path for config.action_mailer.preview_paths where one can add locations for mailer previews for Rails to search, so instead of having a single search path set, you can append multiple search paths:

config.action_mailer.preview_paths << "#{Rails.root}/lib/mailer_previews"

03. error_highlight gem to locate columns with errors.

Ruby 3.1 added the error_highlight gem to display the fine-grained location of where an error occurred. Rails will now use error_highlight on error pages to show the column range of where an error occurred.

04. routes --grep to filter routes by paths.

Rails will extend bin/rails routes --grep to match paths too. So if you run $ bin/rails routes -g /cats/1, you can expect to get:

Prefix Verb   URI Pattern         Controller#Action
   cat GET    /cats/:id(.:format) cats#show
       PATCH  /cats/:id(.:format) cats#update
       PUT    /cats/:id(.:format) cats#update
       DELETE /cats/:id(.:format) cats#destroy

05. ActiveRecord::QueryMethods#select accepts a hash.

If you prefer hashes over raw SQL strings, now you can use them with select when you join tables. For instance instead of:

Post.joins(:comments)
    .select(
      "posts.id as post_id, posts.title as post_title,
      comments.id as comment_id, comments.body as comment_body"
    )

You can do:

Post.joins(:comments)
    .select(
      posts: { id: :post_id, title: :post_title },
      comments: { id: :comment_id, body: :comment_body}
    )

06. Pass options accessor to Cache#fetch block.

With this change, it is possible to pass cache options to the fetch method, so if you use third party auth tokens and store them in the cache, you can set the cache expiry time to the same as the expiry time of the token, so the cache can expire along with the TTL of these third party tokens.

Rails.cache.fetch("3rd-party-token") do |name, options|
  token = fetch_token_from_remote
  # set the cache's TTL to match the token's TTL
  options.expires_in = token.expires_in
  token
end

07. Add :locals to Action View rendering instrumentation.

ActiveSupport::Notifications will now capture :locals in addition to :identifier and :layout. This change is motivated by the need to gain additional insights into the rendering process to enable developers to make more accurat