fix: avoid eager DB connection when loading Journaled::Outbox::Event (#71)

* fix: avoid eager DB connection when loading Journaled::Outbox::Event

Passing a symbol to `attribute` (e.g. `attribute :event_data, :json`)
causes Rails 7.2+ to call `ActiveRecord::Type.adapter_name_from` at
class load time, which requires an active connection pool to resolve the
adapter-specific type. This prevents the class from being autoloaded
without a database connection (e.g. during tapioca gem shim generation).

Replace with a concrete type object (`ActiveRecord::Type::Json.new`),
which bypasses adapter resolution entirely and has identical behavior
on PostgreSQL.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fixup: Test load behavior empirically via a meta test

* Bump version.rb

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: smudge

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    journaled (6.2.6)
+    journaled (6.2.7)
       activejob
       activerecord
       activesupport

app/models/journaled/outbox/event.rb

@@ -16,7 +16,7 @@ class Event < Journaled.outbox_base_class_name.constantize
 
       skip_audit_log
 
-      attribute :event_data, :json
+      attribute :event_data, ActiveRecord::Type::Json.new
 
       validates :event_type, :event_data, :partition_key, :stream_name, presence: true
       validate :failed_at_and_failure_reason_must_be_consistent

gemfiles/rails_7_2.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    journaled (6.2.6)
+    journaled (6.2.7)
       activejob
       activerecord
       activesupport

gemfiles/rails_8_0.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    journaled (6.2.6)
+    journaled (6.2.7)
       activejob
       activerecord
       activesupport

lib/journaled/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Journaled
-  VERSION = "6.2.6"
+  VERSION = "6.2.7"
 end

spec/meta/model_loadability_spec.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+require 'open3'
+
+RSpec.describe 'app/models' do
+  it 'loads all files without a database connection pool configured' do
+    env_file = Rails.root.join('config/environment').to_s
+    gem_root = Rails.root.join('../..').expand_path.to_s
+    model_files = Dir[File.join(gem_root, 'app/models/**/*.rb')]
+
+    file_loads = model_files.map { |f| "load #{f.inspect}" }.join("\n")
+
+    # Boot Rails in development mode (lazy loading), remove all connection pools,
+    # then load each model file. This simulates the conditions under which the bug
+    # was originally discovered: tapioca loading classes without a DB configured.
+    # Rails 7.2+ calls ActiveRecord::Type.adapter_name_from at class load time for
+    # symbol-typed attributes, which raises if no connection pool exists.
+    script = <<~RUBY
+      ENV['RAILS_ENV'] = 'development'
+      require #{env_file.inspect}
+
+      handler = ActiveRecord::Base.connection_handler
+      handler.connection_pool_names.each { |name| handler.remove_connection_pool(name) }
+
+      #{file_loads}
+
+      puts "#{model_files.size} model files loaded successfully"
+    RUBY
+
+    output, status = Open3.capture2e(RbConfig.ruby, '-e', script)
+    expect(status.exitstatus).to eq(0), "Model load failed:\n#{output}"
+  end
+end