FWK-1615 Prevent unnecessary database connections (#8)

Author: ajvondrak

.gitignore

@@ -4,7 +4,6 @@
 .config
 .yardoc
 .idea
-Gemfile.lock
 InstalledFiles
 _yardoc
 coverage
@@ -21,6 +20,5 @@ tmp
 *.o
 *.a
 mkmf.log
-.ruby-version
 coverage/
 results.xml

.ruby-version

@@ -0,0 +1 @@
+3.1.3

Gemfile

@@ -2,3 +2,14 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in activerecord-delay_touching.gemspec
 gemspec
+
+gem "rake"
+
+group :test do
+  gem "sqlite3"
+  gem "timecop"
+  gem "rspec-rails"
+  gem "simplecov"
+  gem "simplecov-rcov"
+  gem "yarjuf"
+end

Gemfile.lock

@@ -0,0 +1,121 @@
+PATH
+  remote: .
+  specs:
+    activerecord-delay_touching (1.1.2)
+      activerecord (>= 4.2, < 6.2)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actionpack (6.1.7.2)
+      actionview (= 6.1.7.2)
+      activesupport (= 6.1.7.2)
+      rack (~> 2.0, >= 2.0.9)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actionview (6.1.7.2)
+      activesupport (= 6.1.7.2)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activemodel (6.1.7.2)
+      activesupport (= 6.1.7.2)
+    activerecord (6.1.7.2)
+      activemodel (= 6.1.7.2)
+      activesupport (= 6.1.7.2)
+    activesupport (6.1.7.2)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      tzinfo (~> 2.0)
+      zeitwerk (~> 2.3)
+    builder (3.2.4)
+    concurrent-ruby (1.2.2)
+    crass (1.0.6)
+    diff-lcs (1.5.0)
+    docile (1.4.0)
+    erubi (1.12.0)
+    i18n (1.12.0)
+      concurrent-ruby (~> 1.0)
+    loofah (2.19.1)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    method_source (1.0.0)
+    mini_portile2 (2.8.1)
+    minitest (5.18.0)
+    nokogiri (1.14.2)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
+    racc (1.6.2)
+    rack (2.2.6.3)
+    rack-test (2.0.2)
+      rack (>= 1.3)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.5.0)
+      loofah (~> 2.19, >= 2.19.1)
+    railties (6.1.7.2)
+      actionpack (= 6.1.7.2)
+      activesupport (= 6.1.7.2)
+      method_source
+      rake (>= 12.2)
+      thor (~> 1.0)
+    rake (13.0.6)
+    rspec (3.12.0)
+      rspec-core (~> 3.12.0)
+      rspec-expectations (~> 3.12.0)
+      rspec-mocks (~> 3.12.0)
+    rspec-core (3.12.1)
+      rspec-support (~> 3.12.0)
+    rspec-expectations (3.12.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.12.0)
+    rspec-mocks (3.12.3)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.12.0)
+    rspec-rails (6.0.1)
+      actionpack (>= 6.1)
+      activesupport (>= 6.1)
+      railties (>= 6.1)
+      rspec-core (~> 3.11)
+      rspec-expectations (~> 3.11)
+      rspec-mocks (~> 3.11)
+      rspec-support (~> 3.11)
+    rspec-support (3.12.0)
+    simplecov (0.22.0)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov-rcov (0.3.1)
+      simplecov (>= 0.4.1)
+    simplecov_json_formatter (0.1.4)
+    sqlite3 (1.6.1)
+      mini_portile2 (~> 2.8.0)
+    thor (1.2.1)
+    timecop (0.9.6)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+    yarjuf (2.0.0)
+      builder
+      rspec (~> 3)
+    zeitwerk (2.6.7)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  activerecord-delay_touching!
+  rake
+  rspec-rails
+  simplecov
+  simplecov-rcov
+  sqlite3
+  timecop
+  yarjuf
+
+BUNDLED WITH
+   2.4.7

Rakefile

@@ -2,7 +2,6 @@ require "bundler/gem_tasks"
 require "rspec/core"
 require "rspec/core/rake_task"
 
-Rake::Task["spec"].clear
 RSpec::Core::RakeTask.new(:spec) do |t|
   t.fail_on_error = false
   t.rspec_opts = %w[-f JUnit -o results.xml]

activerecord-delay_touching.gemspec

@@ -19,13 +19,4 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_dependency             "activerecord", ">= 4.2", "< 6.2"
-
-  spec.add_development_dependency "bundler", "~> 1.6"
-  spec.add_development_dependency "rake"
-  spec.add_development_dependency "sqlite3"
-  spec.add_development_dependency "timecop"
-  spec.add_development_dependency "rspec-rails", "~> 3.0"
-  spec.add_development_dependency "simplecov"
-  spec.add_development_dependency "simplecov-rcov"
-  spec.add_development_dependency "yarjuf"
 end

lib/activerecord/delay_touching.rb

@@ -61,15 +61,15 @@ def self.call
 
     # Apply the touches that were delayed.
     def self.apply
-      begin
+      while state.more_records?
         ActiveRecord::Base.transaction do
           state.records_by_attrs_and_class.each do |attr, classes_and_records|
             classes_and_records.each do |klass, records|
               touch_records attr, klass, records
             end
           end
         end
-      end while state.more_records?
+      end
     ensure
       state.clear_records
     end

spec/activerecord/delay_touching_spec.rb

@@ -125,6 +125,28 @@
     end
   end
 
+  it 'will not connect to the database if there are no touches' do
+    expect(ActiveRecord::Base).not_to receive(:connection)
+    ActiveRecord::Base.delay_touching do
+      # no touches, so no reason to fetch a connection
+    end
+  end
+
+  it 'will not connect to the database if none of the touches are persisted' do
+    expect(ActiveRecord::Base).not_to receive(:connection)
+    ActiveRecord::Base.delay_touching do
+      Pet.new.touch # not persisted, so won't cause updates
+    end
+  end
+
+  it 'still connects to the database for other queries, even if there are no touches' do
+    expect(ActiveRecord::Base.connection).not_to receive(:update) # no touches
+    expect(ActiveRecord::Base).to receive(:connection).at_least(:once).and_call_original
+    ActiveRecord::Base.delay_touching do
+      expect(Pet.count).to be >= 0 # query should still work
+    end
+  end
+
   context 'touch: true' do
     before do
       person.pets << pet1