Add support for Rails 7 (alpha2) (#3)

This:
- Adds an `Appraisal` entry for `7.0.0.alpha2`. (I had to specify multiple gems to get the pre-release dependencies to resolve properly.)
- Bumps `.ruby-version` to `2.7`, but keeps linting at `2.6`. (CI will still run against all of 2.6-3.0)
- Fixes a deprecation warning about `ActiveRecord::Base.default_timezone` (switches to `ActiveRecord.default_timezone`)
- Fixes some YML-autoloading tests by enabling Zeitwerk in the 7.0 test suite. (The `:classic` autoloader is no longer used/supported in Rails 7)
- Autocorrects some new linter rules pulled from the latest version of the linter gem
- Bumps the version to 0.3.0 and updates the CHANGELOG

.github/workflows/ci.yml

@@ -13,9 +13,12 @@ jobs:
           - gemfiles/rails_5_2.gemfile
           - gemfiles/rails_6_0.gemfile
           - gemfiles/rails_6_1.gemfile
+          - gemfiles/rails_7_0.gemfile
         exclude:
           - ruby: 3.0
             gemfile: gemfiles/rails_5_2.gemfile
+          - ruby: 2.6
+            gemfile: gemfiles/rails_7_0.gemfile
     services:
       postgres:
         image: postgres

.rubocop.yml

@@ -9,6 +9,7 @@ inherit_mode:
     - Exclude
 
 AllCops:
+  TargetRubyVersion: 2.6
   Exclude:
     - 'lib/generators/delayed/templates/*.rb'
   NewCops: enable

.ruby-version

@@ -1 +1 @@
-2.6.5
+2.7.4

Appraisals

@@ -9,3 +9,9 @@ end
 appraise 'rails-6-1' do
   gem 'activerecord', '~> 6.1.0'
 end
+
+appraise 'rails-7-0' do
+  gem 'actionmailer', '~> 7.0.0.alpha2'
+  gem 'activejob', '~> 7.0.0.alpha2'
+  gem 'activerecord', '~> 7.0.0.alpha2'
+end

CHANGELOG.md

@@ -11,6 +11,16 @@ and this project aims to adhere to [Semantic Versioning](http://semver.org/spec/
 ### Removed <!-- for now removed features. -->
 ### Fixed <!-- for any bug fixes. -->
 
+## [0.3.0] - 2021-10-26
+### Added
+- Add more official support for Rails 7.0 (currently alpha2). There were no gem conflicts, but this
+  adds an entry to our `Appraisals` file so that we run CI tests against ActiveRecord 7.
+### Fixed
+- Fix Rails 7.0 deprecation warnings caused by usages of `ActiveRecord::Base.default_timestamp`
+- Fix tests that relied on classic autoloader behavior. Now we pull in Zeitwerk where necessary.
+- Fix a couple issues caught by the linter, most notably resulting in a switch from `IO.select(...)`
+  to `IO#wait_readable(...)`, improving support for Ruby 3 scheduler hooks.
+
 ## [0.2.0] - 2021-08-30
 ### Fixed
 - Fix the loading of `Delayed::Job` constant on newly-generated Rails 6.1 apps. (previously, the
@@ -33,6 +43,7 @@ and this project aims to adhere to [Semantic Versioning](http://semver.org/spec/
   ancestor repos (`delayed_job` and `delayed_job_active_record`), plus the changes from Betterment's
   internal forks.
 
+[0.3.0]: https://github.com/betterment/delayed/compare/v0.2.0...v0.3.0
 [0.2.0]: https://github.com/betterment/delayed/compare/v0.1.1...v0.2.0
 [0.1.1]: https://github.com/betterment/delayed/compare/v0.1.0...v0.1.1
 [0.1.0]: https://github.com/betterment/delayed/releases/tag/v0.1.0

app/models/delayed/job.rb

@@ -163,13 +163,19 @@ def self.reserve_with_scope_using_optimized_mssql(ready_scope, worker, now)
     def self.db_time_now
       if Time.zone
         Time.zone.now
-      elsif ::ActiveRecord::Base.default_timezone == :utc
+      elsif default_timezone == :utc
         Time.now.utc
       else
         Time.current
       end
     end
 
+    if ActiveRecord::VERSION::MAJOR >= 7
+      def self.default_timezone
+        ActiveRecord.default_timezone
+      end
+    end
+
     def self.worker_tags(worker)
       {
         min_priority: worker.min_priority,

delayed.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.require_paths  = ['lib']
   spec.summary        = 'a multi-threaded, SQL-driven ActiveJob backend used at Betterment to process millions of background jobs per day'
 
-  spec.version        = '0.2.0'
+  spec.version        = '0.3.0'
   spec.metadata       = {
     'changelog_uri' => 'https://github.com/betterment/delayed/blob/main/CHANGELOG.md',
     'bug_tracker_uri' => 'https://github.com/betterment/delayed/issues',
@@ -40,4 +40,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rspec'
   spec.add_development_dependency 'sqlite3'
   spec.add_development_dependency 'timecop'
+  spec.add_development_dependency 'zeitwerk'
 end

gemfiles/rails_7_0.gemfile

@@ -0,0 +1,9 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "actionmailer", "~> 7.0.0.alpha2"
+gem "activejob", "~> 7.0.0.alpha2"
+gem "activerecord", "~> 7.0.0.alpha2"
+
+gemspec path: "../"

lib/delayed/priority.rb

@@ -150,7 +150,7 @@ def <=>(other)
     private
 
     def respond_to_missing?(method_name, include_private = false)
-      method_name.to_s.end_with?('?') && self.class.names.key?(method_name.to_s[0..-2].to_sym) || super
+      (method_name.to_s.end_with?('?') && self.class.names.key?(method_name.to_s[0..-2].to_sym)) || super
     end
 
     def method_missing(method_name, *args)

lib/delayed/runnable.rb

@@ -21,7 +21,7 @@ def start
     def on_exit!; end
 
     def interruptable_sleep(seconds)
-      IO.select([pipe[0]], nil, nil, seconds)
+      pipe[0].wait_readable(seconds)
     end
 
     def stop

spec/delayed/job_spec.rb

@@ -739,10 +739,16 @@ def create_job(opts = {})
     end
   end
 
+  if ActiveRecord::VERSION::MAJOR >= 7
+    delegate :default_timezone=, to: ActiveRecord
+  else
+    delegate :default_timezone=, to: ActiveRecord::Base
+  end
+
   context "db_time_now" do
     after do
       Time.zone = nil
-      ActiveRecord::Base.default_timezone = :local
+      self.default_timezone = :local
     end
 
     it "returns time in current time zone if set" do
@@ -752,13 +758,13 @@ def create_job(opts = {})
 
     it "returns UTC time if that is the AR default" do
       Time.zone = nil
-      ActiveRecord::Base.default_timezone = :utc
+      self.default_timezone = :utc
       expect(described_class.db_time_now.zone).to eq "UTC"
     end
 
     it "returns local time if that is the AR default" do
       Time.zone = "Arizona"
-      ActiveRecord::Base.default_timezone = :local
+      self.default_timezone = :local
       expect(described_class.db_time_now.zone).to eq("MST")
     end
   end

spec/helper.rb

@@ -139,8 +139,15 @@ class SingletonClass
   end
 end
 
-# Add this directory so the ActiveSupport autoloading works
-ActiveSupport::Dependencies.autoload_paths << File.dirname(__FILE__)
+if ActiveRecord::VERSION::MAJOR >= 7
+  require "zeitwerk"
+  loader = Zeitwerk::Loader.new
+  loader.push_dir File.dirname(__FILE__)
+  loader.setup
+else
+  # Add this directory so the ActiveSupport autoloading works
+  ActiveSupport::Dependencies.autoload_paths << File.dirname(__FILE__)
+end
 
 RSpec::Matchers.define :emit_notification do |expected_event_name|
   attr_reader :actual, :expected

spec/yaml_ext_spec.rb

@@ -25,7 +25,7 @@
   it 'autoloads the class of an anonymous struct' do
     expect {
       yaml = "--- !ruby/struct\nn: 1\n"
-      object = YAML.load(yaml)
+      object = load_with_delayed_visitor(yaml)
       expect(object).to be_kind_of(Struct)
       expect(object.n).to eq(1)
     }.not_to raise_error