Merge branch 'stokarenko-fix-after-commit-within-nested-transaction-vol2'

Appraisals

@@ -29,6 +29,7 @@ appraise 'rails_5.0' do
   gem 'dynamoid', '~> 1.3', platforms: :ruby
   gem 'aws-sdk', '~> 2', platforms: :ruby
   gem 'redis-objects'
+  gem "after_commit_everywhere", "~> 0.1", ">= 0.1.5"
 end
 
 appraise 'rails_5.0_nobrainer' do
@@ -43,6 +44,7 @@ appraise 'rails_5.1' do
   gem 'dynamoid', '~> 1.3', platforms: :ruby
   gem 'aws-sdk', '~>2', platforms: :ruby
   gem 'redis-objects'
+  gem "after_commit_everywhere", "~> 0.1", ">= 0.1.5"
 end
 
 appraise 'rails_5.2' do
@@ -52,9 +54,11 @@ appraise 'rails_5.2' do
   gem 'dynamoid', '~>2.2', platforms: :ruby
   gem 'aws-sdk', '~>2', platforms: :ruby
   gem 'redis-objects'
+  gem "after_commit_everywhere", "~> 0.1", ">= 0.1.5"
 end
 
 appraise 'norails' do
+  gem 'sqlite3', '~> 1.3', '>= 1.3.5', platforms: :ruby
   gem 'rails', install_if: false
   gem 'sequel'
   gem 'redis-objects'

README.md

@@ -981,6 +981,12 @@ job.run
 job.save! #notify_about_running_job is not run
 ```
 
+Please note that `:after_commit` AASM callbacks behaves around custom implementation
+of transaction pattern rather than a real-life DB transaction. This fact still causes
+the race conditions and redundant callback calls within nested transaction. In order
+to fix that it's highly recommended to add `gem 'after_commit_everywhere', '~> 0.1', '>= 0.1.5'`
+to your `Gemfile`.
+
 If you want to encapsulate state changes within an own transaction, the behavior
 of this nested transaction might be confusing. Take a look at
 [ActiveRecord Nested Transactions](http://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html)

gemfiles/rails_5.0.gemfile

@@ -9,5 +9,6 @@ gem "sequel"
 gem "dynamoid", "~> 1.3", platforms: :ruby
 gem "aws-sdk", "~> 2", platforms: :ruby
 gem "redis-objects"
+gem "after_commit_everywhere", "~> 0.1", ">= 0.1.5"
 
 gemspec path: "../"

gemfiles/rails_5.1.gemfile

@@ -9,5 +9,6 @@ gem "sequel"
 gem "dynamoid", "~> 1.3", platforms: :ruby
 gem "aws-sdk", "~>2", platforms: :ruby
 gem "redis-objects"
+gem "after_commit_everywhere", "~> 0.1", ">= 0.1.5"
 
 gemspec path: "../"

gemfiles/rails_5.2.gemfile

@@ -9,5 +9,6 @@ gem "sequel"
 gem "dynamoid", "~>2.2", platforms: :ruby
 gem "aws-sdk", "~>2", platforms: :ruby
 gem "redis-objects"
+gem "after_commit_everywhere", "~> 0.1", ">= 0.1.5"
 
 gemspec path: "../"

lib/aasm/persistence/active_record_persistence.rb

@@ -28,6 +28,19 @@ module AASM
       #   end
       #
       def self.included(base)
+        begin
+          require 'after_commit_everywhere'
+          raise LoadError unless Gem::Version.new(::AfterCommitEverywhere::VERSION) >= Gem::Version.new('0.1.5')
+
+          base.send(:include, ::AfterCommitEverywhere) unless base.include?(::AfterCommitEverywhere)
+          base.send(:alias_method, :aasm_execute_after_commit, :after_commit)
+        rescue LoadError
+          warn <<-MSG
+[DEPRECATION] :after_commit AASM callback is not safe in terms of race conditions and redundant calls.
+              Please add `gem 'after_commit_everywhere', '~> 0.1', '>= 0.1.5'` to your Gemfile in order to fix that.
+          MSG
+        end
+
         base.send(:include, AASM::Persistence::Base)
         base.send(:include, AASM::Persistence::ORM)
         base.send(:include, AASM::Persistence::ActiveRecordPersistence::InstanceMethods)

lib/aasm/persistence/orm.rb

@@ -81,6 +81,10 @@ module AASM
         true
       end
 
+      def aasm_execute_after_commit
+        yield
+      end
+
       def aasm_write_state_attribute(state, name=:default)
         aasm_write_attribute(self.class.aasm(name).attribute_name, aasm_raw_attribute_value(state, name))
       end
@@ -116,32 +120,32 @@ module AASM
 
       # Returns true if event was fired successfully and transaction completed.
       def aasm_fire_event(state_machine_name, name, options, *args, &block)
-        if aasm_supports_transactions? && options[:persist]
-          event = self.class.aasm(state_machine_name).state_machine.events[name]
-          event.fire_callbacks(:before_transaction, self, *args)
-          event.fire_global_callbacks(:before_all_transactions, self, *args)
+        return super unless aasm_supports_transactions? && options[:persist]
 
-          begin
-            success = if options[:persist] && use_transactions?(state_machine_name)
-              aasm_transaction(requires_new?(state_machine_name), requires_lock?(state_machine_name)) do
-                super
-              end
-            else
+        event = self.class.aasm(state_machine_name).state_machine.events[name]
+        event.fire_callbacks(:before_transaction, self, *args)
+        event.fire_global_callbacks(:before_all_transactions, self, *args)
+
+        begin
+          success = if options[:persist] && use_transactions?(state_machine_name)
+            aasm_transaction(requires_new?(state_machine_name), requires_lock?(state_machine_name)) do
               super
             end
+          else
+            super
+          end
 
-            if success
+          if success
+            aasm_execute_after_commit do
               event.fire_callbacks(:after_commit, self, *args)
               event.fire_global_callbacks(:after_all_commits, self, *args)
             end
-
-            success
-          ensure
-            event.fire_callbacks(:after_transaction, self, *args)
-            event.fire_global_callbacks(:after_all_transactions, self, *args)
           end
-        else
-          super
+
+          success
+        ensure
+          event.fire_callbacks(:after_transaction, self, *args)
+          event.fire_global_callbacks(:after_all_transactions, self, *args)
         end
       end
 

spec/unit/persistence/active_record_persistence_spec.rb

@@ -613,6 +613,38 @@ if defined?(ActiveRecord)
           expect(validator).to be_running
           expect(validator.name).to eq("name")
         end
+
+        context "nested transaction" do
+          it "should fire :after_commit if root transaction was successful" do
+            validator = Validator.create(:name => 'name')
+            expect(validator).to be_sleeping
+
+            validator.transaction do
+              validator.run!
+              expect(validator.name).to eq("name")
+              expect(validator).to be_running
+            end
+
+            expect(validator.name).to eq("name changed")
+            expect(validator.reload).to be_running
+          end
+
+          it "should not fire :after_commit if root transaction failed" do
+            validator = Validator.create(:name => 'name')
+            expect(validator).to be_sleeping
+
+            validator.transaction do
+              validator.run!
+              expect(validator.name).to eq("name")
+              expect(validator).to be_running
+
+              raise ActiveRecord::Rollback, "failed on purpose"
+            end
+
+            expect(validator.name).to eq("name")
+            expect(validator.reload).to be_sleeping
+          end
+        end
       end
 
       describe 'before and after transaction callbacks' do