Ruby on Rails - June 2025

All the Rails News That Matters, Once a Month!

Ruby on Rails - June 2025 by Sajjad Umar

Hey everyone — Sajjad Umar here with the June edition of Ruby on Rails Monthly!

As we reach the year's midpoint, the Rails ecosystem continues its impressive momentum with critical security updates, database enhancements, and exciting community events. This month brings us smarter Active Job handling, important Trix vulnerability patches, and new cache control capabilities - all while the Rails team prepares for the historic final RailsConf. Let's explore what's been shaping the Rails landscape these past weeks!

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• rubyonrails.pk - for the love of rails in Pakistan

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Rails Foundation Announcement

The Rails Foundation confirmed that Rails World 2025 sessions will be recorded and published on YouTube:

• Opening/Closing keynotes available immediately

• All other sessions published shortly after
  Watch recordings here

Community Guides Needing Your Input

Three documentation improvements are open for community review:

1. Active Record Encryption Guide Refresh
   Review PR #55188
   Help refine Rails' built-in encryption documentation - particularly valuable for developers working with sensitive data

2. Threading & Code Execution Guide Update
   Contribute to PR #55179
   Perfect opportunity if you have experience with concurrent Rails applications or background processing

3. PostgreSQL Guide Consolidation
   Join discussion on PR #55135
   Help merge API docs with usage guides for better Postgres navigation

Why participate? Your review ensures these resources stay accurate for the entire community!

Final RailsConf Announcement

The last RailsConf (July 8-10, Philadelphia) will feature:

• Fireside chat with DHH

• Talks by Rails core team members including Eileen Uchitelle (Core), Gannon McGibbon (Committers), Hartley McGuire (Issues), and Matheus Richard (Triage)

• Discussions on Rails' future direction
  Tickets remain available for this historic event.
  Conference Details

SQLite Adapter Precision Fix

PR #55180 brings accurate row counting to SQLite:

# Before: Inconsistent counts
User.where(active: true).update_all(status: :verified)
# => Might report incorrect numbers due to cascading deletes

# After: Precise affected rows
User.where(active: true).update_all(status: :verified)
# => Returns exact count of modified records

Key improvements:

• Fixes overcounting from cascading operations

• Eliminates false positives on read-only queries

• Uses SQLite's native counters more intelligently

Affects all SQLite users - especially important for audit trails

Unified Transaction Isolation Control

PR #55176 simplifies isolation management:

# New streamlined approach
ActiveRecord.with_transaction_isolation_level(:serializable) do
  Shard1.connection.transaction { ... }
  Shard2.connection.transaction { ... }
end

# Old method: Manual per-connection setup
[Shard1, Shard2].each do |shard|
  shard.connection_pool.with_connection do |conn|
    conn.transaction(isolation: :serializable) { ... }
  end
end

Why this matters:

1. Single declaration for all databases/shards

2. Eliminates connection pool iteration

3. 40% less boilerplate in multi-db transactions

4. Works seamlessly with transactional tests

Essential for financial systems and multi-tenant applications

Active Job Continuations Upgrade

PR #55174 enhances pausable jobs:

class DataExportJob < ApplicationJob
  include ActiveJob::Continuations

  def perform
    checkpoint :extract_data, retry: :exponential
    checkpoint :transform, retry: [3, 5.minutes]
    checkpoint :load_to_warehouse
  end
end

Key improvements:

• Timing adjustment: Checkpoints now execute before job steps

• New instrumentation: Runtime metrics for each checkpoint

• Transaction safety: Automatic detection of checkpoint-in-transaction anti-pattern

• Order validation: Ensures step consistency during job resumption

• Configurable retries: Per-checkpoint retry strategies

Critical for ETL pipelines and long-running background tasks

PostgreSQL Documentation Restructuring

The PostgreSQL-specific guide has been integrated into Rails' core API documentation. This change helps developers by:

• Removing database-specific details from general Active Record guides

• Centralizing PostgreSQL reference material for easier lookup

• Making room for future database adapters in the documentation structure
  Implementation details in PR #55135

Active Job Continuations Refinements

Building on last month's pausable jobs feature, this update addresses edge cases discovered during real-world use:

• Added safety checks to prevent job resumption in inconsistent states

• Fixed race conditions during multi-step job execution

• Improved error messages for failed checkpoint transitions
  Follow-up PR #55151

Action Text Upload Progress Accuracy

File upload progress bars now reflect server-side processing time. Previously, progress indicators would stall at 100% during server processing. The update:

• Adds hidden timing instrumentation to Trix uploads

• Calculates backend processing time estimates

• Provides smoother progress bar animation
  Technical solution in PR #55157

Current Attributes Leak Fix

Fixed a subtle memory leak where Current attributes could persist between requests. This could cause:

• User A seeing User B's attributes in multi-tenant apps

• Accumulating memory in long-running processes

• Security concerns with sensitive data
  The patch ensures complete attribute reset after each request.
  Critical fix in PR #55139

Minitest Plugin Compatibility

Resolved conflicts with test plugins like minitest-focus by changing test loading order:

• Test files now load before plugins initialize

• Maintains plugin functionality while preventing overrides

• Solves "focus tag ignored" issues reported by users
  Compatibility fix in PR #55140

CI Optimization

Eliminated duplicate test runs in GitHub Actions:

• Separated unit tests from system tests

• Reduces CI time by ~18 minutes per run

• Lowers resource consumption for Rails maintainers
  Workflow change in PR #55136

HEAD Request Compliance

Fixed Rack::Lint violations to meet RFC9110 standards:

• HEAD requests now return empty bodies during errors

• Resolves compatibility issues with Rack 3+

• Ensures proper behavior in API-only applications
  Spec compliance in PR #55149

Job Retry Consistency

Preserves original job attributes during retries:

• Maintains initial scheduled time instead of resetting

• Retains original queue name and priority settings

• Prevents unexpected behavior in job monitoring tools
  Behavior fix in PR #55141

Active Job Continuations Introduction

PR #55127 adds pausable/resumable jobs:

class DataImportJob
  include ActiveJob::Continuable
  
  def perform(import_id)
    @import = Import.find(import_id)
    
    step :initialize do
      @import.prepare # Runs immediately
    end
    
    step :process do |step|
      @import.records.find_each(start: step.cursor) do |record|
        record.transform
        step.advance!(from: record.id) # Saves progress
      end
    end
    
    step :finalize # Method-based step
  end
  
  private
  def finalize
    @import.cleanup # Runs after resumption
  end
end

Key benefits:

• Survives server restarts during long jobs

• Automatic progress saving between steps

• Works with any queuing backend

GitHub Actions Optimization

PR #55120 simplifies CI configuration by removing redundant ruby-version input - the setup-ruby action now automatically detects .ruby-version files.

Reflection Cache Performance

PR #55115 boosts association performance by memoizing reflection validations. Since associations can't change after definition, this:

• Eliminates redundant metadata checks

• Speeds up model initialization

• Particularly benefits apps with complex relational mappings

Rails DOM Testing 2.3.0

New release adds:

assert_not_dom expected, actual
# Equivalent to: assert_not_equal expected, actual

Use case:

• Verifies DOM elements are absent

• Improves integration test readability

• Complements existing assert_dom helper

Documentation Clarification: Polymorphic :through Restriction

Rails now explicitly documents that polymorphic associations cannot be used with :through. This restriction exists because polymorphic associations rely on dual-column references (_id + _type), while :through assumes single-column foreign keys. Attempting this pattern already raised errors, but the exception was previously undocumented.
Implementation details in PR #55107

Deprecation Notice: :class_name in Polymorphic belongs_to

Using :class_name with polymorphic belongs_to is now deprecated (scheduled for removal in Rails 8.1). The _type column already stores the associated class name, making this option redundant and potentially misleading.
Deprecation rationale in PR #55091

# DEPRECATED (remove class_name):
belongs_to :reviewable, polymorphic: true, class_name: "Product"

# CORRECT:
belongs_to :reviewable, polymorphic: true

Enhanced Database Control: Namespaced db:migrate:reset

This PR introduces database-specific reset commands for multi-DB setups. This prevents accidental full-database resets in production and enables targeted schema management.
Command implementation in PR #55077

# Resets ONLY primary database:
bin/rails db:migrate:reset:primary

# Resets animals database:
bin/rails db:migrate:reset:animals

---

Schema Loading Fix: SCHEMA_FORMAT Consistency

The db:schema:load command now correctly respects ENV["SCHEMA_FORMAT"] in Rails 7.2. This fixes CI/CD workflows where schema format differs between environments by allowing runtime overrides of config.active_record.schema_format.
Behavior fix in PR #55059

# Load SQL structure:
SCHEMA_FORMAT=sql bin/rails db:schema:load

# Load Ruby schema:
SCHEMA_FORMAT=ruby bin/rails db:schema:load

Database Operation Insights

PR #55060 introduces affected_rows for SQL operations:

result = ActiveRecord::Base.connection.exec_query("
  UPDATE posts SET status = 'published' 
  WHERE created_at < NOW() - INTERVAL '1 year'
")
result.affected_rows # => 342

Use cases:

• Verify batch operation impact

• Audit log reporting

• Performance monitoring

---

Action Text Maintenance Improvements

1. Trix Extraction
   PR #55058 migrates Trix to standalone gem:

• Faster security updates independent of Rails releases

• Simplified maintenance for core team

• No application changes required

2. Security Update
   PR #55046 addresses CVE-2025-46812 in Trix 2.1.15:

• Critical: XSS vulnerability in rich text sanitization

• Action required: Update via bundle update actiontext

Ruby 3.5 Compatibility

PR #55037 optimizes CGI handling:

• Loads only cgi/escape instead of full gem

• Eliminates deprecation warnings

• Maintains functionality as Ruby retires stdlib CGI

HTTP Cache Control Directives

PR #55033 implements RFC-9111 support:

# Check client cache directives
if request.cache_control_directives.max_stale?
  serve_stale_content
elsif request.cache_control_directives.no_cache?
  force_fresh_response
end

New directives available:

• only_if_cached? - Client accepts stale content

• max_stale? - Permits expired responses

• min_fresh - Requires minimum freshness duration

• no_cache? - Forces revalidation

Sharpen Your Rails Skills This Summer
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• Exclusive content on Hotwire optimization

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Until next month, keep building extraordinary things with Rails! The community thrives when we share knowledge and grow together.

Sajjad Umar
Founder, Ruby on Rails Monthly
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