feat: support of multidb

[seuros]

closes #85 #95 #100

The Problem

Previously, if you had 2 adapters of different types, you had to segregate your app or this gem would randomly patch stuff. Like, imagine having PostgreSQL for your main models and MySQL for analytics - the gem would just
pick one adapter type and YOLO apply it to everything. Your MySQL models would try to call pg_advisory_lock. Fun times.

Since we're in 2025 and not the 1950s, I upgraded this gem to follow Rails' multi-DB architecture properly. I tried many time to do this without much success but lot of learning.

What Was Broken

The old architecture used a singleton Base class that would detect your database type on first use and remember it forever. So if your first model happened to be PostgreSQL, congrats - all your MySQL models now think
they're PostgreSQL too. They will use the wrong pronouns and dialect.

JRuby users? LOL, the gem just didn't work at all because JRuby loads adapters differently and our ActiveSupport hooks never fired.

The Fix

• Killed the singleton Base class with fire
• Now we inject our modules directly into each adapter class using prepend
• Each connection gets the correct advisory lock implementation for its database type
• Added JRuby support by detecting RUBY_ENGINE and using a different injection strategy
• Refactored tests to actually test both PostgreSQL AND MySQL in same ran.

Breaking Changes

If you were using private APIs like WithAdvisoryLock::Base or DatabaseAdapterSupport - sorry not sorry, they're gone. The public API stays exactly the same because I'm not a monster.

JRuby Note

@headius @enebo - Quick question: Are you planning to add support for ActiveSupport's adapter-specific load hooks (:active_record_postgresqladapter, :active_record_mysql2adapter)?
Right now we have a special jruby_adapter.rb file that hooks into the connection method because these hooks don't fire on JRuby. If this is a special-needs architecture thing, we'll keep our workaround. If it's something you're
planning to support, we can eventually clean this up.

TL;DR

Multi-database setups now work correctly. Each adapter gets its own implementation. JRuby users can finally use this gem. Welcome to 2025.

[Copilot]

Pull Request Overview

This PR merges and simplifies CI configuration, removes legacy adapter support code, and refactors advisory‐lock implementation into modular concerns.

• Introduces new modules for core advisory logic, MySQL adapters, JRuby support, and lock stack items
• Removes legacy Base, DatabaseAdapterSupport, old gemfiles, Appraisals, and separate workflow ymls
• Updates Docker Compose, Rakefile, Makefile, Gemfile, and consolidates CI into a single .github/workflows/ci.yml

Reviewed Changes

Copilot reviewed 55 out of 55 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
lib/with_advisory_lock/mysql_advisory.rb	New MySQL advisory‐lock concern
lib/with_advisory_lock/core_advisory.rb	Core advisory logic and stack management
lib/with_advisory_lock/jruby_adapter.rb	JRuby compatibility layer for injecting advisory modules
lib/with_advisory_lock/concern.rb	Public API for advisory-lock methods on ActiveRecord::Base
lib/with_advisory_lock/lock_stack_item.rb	Defines a simple data object for tracking locks
lib/with_advisory_lock.rb	Entry point: autoloads, ActiveSupport hooks, debug logging, JRuby hook
docker-compose.yml	Upgrades Postgres image and remaps host ports
Rakefile	Adds frozen literal, rails tasks setup, and loads dummy app tasks
Makefile	Simplifies test target, adds setup-db, removes per-adapter targets
Gemfile	Adds default gems, versioned ActiveRecord, dotenv, railties
.github/workflows/ci.yml	Single consolidated CI workflow for Ruby/Rails matrix
Multiple old gemfiles, Appraisals, ci-postgresql.yml, ci-mysql8.yml	Removed legacy appraisal/gemfile and workflow configurations

Comments suppressed due to low confidence (5)

lib/with_advisory_lock.rb:9

• The autoload references 'with_advisory_lock/result' but no corresponding lib/with_advisory_lock/result.rb was added. Add the missing file or remove this autoload to prevent load errors.

autoload :Result, 'with_advisory_lock/result'

lib/with_advisory_lock.rb:14

• The autoload references 'with_advisory_lock/postgresql_advisory' but no corresponding lib/with_advisory_lock/postgresql_advisory.rb was added. Add the missing file or remove this autoload to prevent load errors.

autoload :PostgreSQLAdvisory, 'with_advisory_lock/postgresql_advisory'

lib/with_advisory_lock.rb:17

• The autoload references 'with_advisory_lock/failed_to_acquire_lock' but no corresponding lib/with_advisory_lock/failed_to_acquire_lock.rb was added. Add the missing file or remove this autoload to prevent load errors.

autoload :FailedToAcquireLock, 'with_advisory_lock/failed_to_acquire_lock'

lib/with_advisory_lock.rb:5

• [nitpick] Consider requiring 'active_support/concern' explicitly (and any other needed parts of ActiveSupport) to ensure ActiveSupport::Concern and related extensions are loaded correctly.

require 'active_support'

lib/with_advisory_lock.rb:23

• [nitpick] Using puts for debug logging can clutter STDOUT; consider using a proper logger or removing this in production code.

puts '[WithAdvisoryLock] Loaded into ActiveRecord' if ENV['DEBUG_LOAD']