Prevent deleting processing image while attachment is processing

lib/delayed_paperclip.rb

@@ -1,5 +1,6 @@
 require 'delayed_paperclip/jobs'
 require 'delayed_paperclip/attachment'
+require 'delayed_paperclip/storage'
 require 'delayed_paperclip/url_generator'
 require 'delayed_paperclip/railtie'
 

lib/delayed_paperclip/attachment.rb

@@ -4,13 +4,23 @@ module Attachment
     def self.included(base)
       base.send :include, InstanceMethods
       base.send :attr_accessor, :job_is_processing
+      base.alias_method_chain :initialize, :delay
       base.alias_method_chain :post_processing, :delay
       base.alias_method_chain :post_processing=, :delay
       base.alias_method_chain :save, :prepare_enqueueing
     end
 
     module InstanceMethods
 
+      def initialize_with_delay(*args)
+        initialize_without_delay(*args)
+
+         # Extend our storage module after Paperclip extends their storage
+         # module so we can add some functionality to the #exists? method for
+         # all storages and still super to their original implementation.
+        self.extend Storage
+      end
+
       def delayed_options
         options[:delayed]
       end

lib/delayed_paperclip/storage.rb

@@ -0,0 +1,17 @@
+module DelayedPaperclip
+  module Storage
+
+    # If the style is processing, it doesn't exist yet. Otherwise, let
+    # Paperclip's storage adapter determine if it exists.
+    #
+    # Technically the job may currently be processing and have already generated
+    # some styles but this will continue to return false until all styles are
+    # finished processing.
+    def exists?(style_name = default_style)
+      return false if processing_style?(style_name)
+
+      super
+    end
+
+  end
+end

spec/integration/examples/base.rb

@@ -312,5 +312,74 @@
     end
   end
 
+  describe 'destroying the model' do
+     it 'deletes all styles when not processing' do
+       reset_class "Dummy", with_processed: true,
+                            paperclip: {
+                              styles: {
+                                thumbnail: '12x12'
+                              }
+                            }
+
+        dummy.save!
+        process_jobs
+
+        dummy.reload
+
+        expect(dummy.image.url(:original)).to start_with("/system/dummies/images/000/000/001/original/12k.png")
+        expect(dummy.image.exists?(:original)).to be_truthy
+        expect(dummy.image.url(:thumbnail)).to start_with("/system/dummies/images/000/000/001/thumbnail/12k.png")
+        expect(dummy.image.exists?(:thumbnail)).to be_truthy
+
+        dummy.destroy!
+
+        expect(dummy.image.exists?(:original)).to be_falsey
+        expect(dummy.image.exists?(:thumbnail)).to be_falsey
+     end
+
+     it 'deletes only the non-delayed styles when processing' do
+      # Copy the processing image into the public folder
+      FileUtils.mkdir_p(Pathname.new(ROOT).join('spec', 'tmp', 'public', 'images'))
+      FileUtils.cp(
+        Pathname.new(ROOT).join('spec', 'fixtures', 'processing.gif'),
+        Pathname.new(ROOT).join('spec', 'tmp', 'public', 'images')
+      )
+
+       reset_class "Dummy", with_processed: true,
+                            only_process: [:thumbnail],
+                            processing_image_url: '/images/processing.gif',
+                            paperclip: {
+                              styles: {
+                                thumbnail: '12x12'
+                              },
+                              only_process: [:original]
+                            }
+
+        dummy.save!
+
+        dummy.reload
+
+        original_path = dummy.image.path(:original)
+        thumbnail_path = dummy.image.path(:thumbnail)
+
+        expect(original_path).to include("/system/dummies/images/000/000/001/original/12k.png")
+        expect(thumbnail_path).to include("/images/processing.gif")
+
+        expect(File.exist?(original_path)).to be_truthy
+        expect(File.exist?(thumbnail_path)).to be_truthy
+
+        expect(dummy.image.exists?(:original)).to be_truthy
+        expect(dummy.image.exists?(:thumbnail)).to be_falsey
+
+        dummy.destroy!
+
+        expect(dummy.image.exists?(:original)).to be_falsey
+        expect(dummy.image.exists?(:thumbnail)).to be_falsey
+
+        expect(File.exist?(original_path)).to be_falsey
+        expect(File.exist?(thumbnail_path)).to be_truthy
+     end
+  end
+
 end