fix: remove uploaded files if transaction is rolled back

lib/carrierwave/mount.rb

@@ -199,10 +199,22 @@ def store_previous_changes_for_#{column}
           @_previous_changes_for_#{column} = attribute_changes[_mounter(:#{column}).serialization_column]
         end
 
+        def reset_previous_changes_for_#{column}
+          # We use this variable to pass information from save time to commit time.
+          # Make sure this doesn't persist across multiple transactions
+          @_previous_changes_for_#{column} = nil
+        end
+
         def remove_previously_stored_#{column}
           before, after = @_previous_changes_for_#{column}
           _mounter(:#{column}).remove_previous([before], [after])
         end
+
+        def remove_rolled_back_#{column}
+          before, after = @_previous_changes_for_#{column}
+          _mounter(:#{column}).remove_previous([after], [before])
+          @_previous_changes_for_#{column} = nil
+        end
       RUBY
     end
 
@@ -351,9 +363,23 @@ def store_previous_changes_for_#{column}
           @_previous_changes_for_#{column} = attribute_changes[_mounter(:#{column}).serialization_column]
         end
 
+        def reset_previous_changes_for_#{column}
+          # We use this variable to pass information from save time to commit time.
+          # Make sure this doesn't persist across multiple transactions
+          @_previous_changes_for_#{column} = nil
+        end
+
         def remove_previously_stored_#{column}
+          return unless @_previous_changes_for_#{column}
           _mounter(:#{column}).remove_previous(*@_previous_changes_for_#{column})
         end
+
+        def remove_rolled_back_#{column}
+          return unless @_previous_changes_for_#{column}
+          before, after = @_previous_changes_for_#{column}
+          _mounter(:#{column}).remove_previous(after, before)
+          @_previous_changes_for_#{column} = nil
+        end
       RUBY
     end
 

lib/carrierwave/orm/activerecord.rb

@@ -56,12 +56,15 @@ def mount_base(column, uploader=nil, options={}, &block)
       validates_processing_of column if uploader_option(column.to_sym, :validate_processing)
       validates_download_of column if uploader_option(column.to_sym, :validate_download)
 
+      after_save :"store_#{column}!"
       before_save :"write_#{column}_identifier"
-      after_save :"store_previous_changes_for_#{column}"
       after_commit :"remove_#{column}!", :on => :destroy
       after_commit :"mark_remove_#{column}_false", :on => :update
+
+      after_save :"store_previous_changes_for_#{column}"
+      after_commit :"reset_previous_changes_for_#{column}"
       after_commit :"remove_previously_stored_#{column}", :on => :update
-      after_commit :"store_#{column}!", :on => [:create, :update]
+      after_rollback :"remove_rolled_back_#{column}"
 
       mod = Module.new
       prepend mod

spec/orm/activerecord_spec.rb

@@ -785,6 +785,45 @@ def filename
       end
       expect(File.exist?(public_path('uploads/old.jpeg'))).to be_truthy
     end
+
+    it 'should remove new file if transaction is rollback' do
+      Event.transaction do
+        @event.image = stub_file('new.jpeg')
+        @event.save
+        expect(File.exist?(public_path('uploads/new.jpeg'))).to be_truthy
+        raise ActiveRecord::Rollback
+      end
+      expect(File.exist?(public_path('uploads/new.jpeg'))).to be_falsey
+    end
+
+    it 'should give correct url during transaction' do
+      Event.transaction do
+        @event.image = stub_file('new.jpeg')
+        @event.save
+        expect(@event.image_url).to eq '/uploads/new.jpeg'
+        raise ActiveRecord::Rollback
+      end
+    end
+
+    it 'should raise error at save if storage cannot be done, preserving old' do
+      allow(@event).to receive(:store_image!).and_raise(CarrierWave::UploadError)
+      Event.transaction do
+        @event.image = stub_file('new.jpeg')
+        expect{ @event.save }.to raise_error(CarrierWave::UploadError)
+        raise ActiveRecord::Rollback
+      end
+      expect(File.exist?(public_path('uploads/old.jpeg'))).to be_truthy
+    end
+
+    it 'should remove new file if transaction is rollback' do
+      Event.transaction do
+        @event.image = stub_file('new.jpeg')
+        @event.save
+        expect(File.exist?(public_path('uploads/new.jpeg'))).to be_truthy
+        raise ActiveRecord::Rollback
+      end
+      expect(File.exist?(public_path('uploads/new.jpeg'))).to be_falsey
+    end
   end
 
   describe "#mount_uploader into transaction" do