Add .xlsx unzip unmodified support since .xlsx files can be a natural zip file

app/models/dunlop/source_file_model.rb

@@ -48,7 +48,8 @@ module Dunlop::SourceFileModel
 
   def unzip_working_file
     source_path = if original_file.try(:options).try(:[], :storage) == :s3
-      temp = Tempfile.new 'temp' # keep reference for tempfile till unzip completed
+      filename = original_file.original_filename.to_s
+      temp = Tempfile.new([filename, File.extname(filename)]) # keep reference for tempfile till unzip completed and keep extension preserved
       temp.binmode
       open( original_file.expiring_url ) { |data| temp.write data.read }
       temp.close

app/models/dunlop/target_file_model.rb

@@ -184,9 +184,10 @@ module Dunlop::TargetFileModel
     def activate_dunlop!
     end
 
-    def generate!(resource = nil)
+    # Allow resource as argument. Changed from resource to rsrc to be sure to avoid method naming collision confusion
+    def generate!(rsrc = nil)
       new_record = create
-      new_record.resource = resource if resource.present?
+      new_record.resource = rsrc if rsrc.present?
       new_record.execute_generation_process
       new_record
     end

app/services/dunlop/file_zip.rb

@@ -3,7 +3,11 @@ module Dunlop::FileZip
   def self.unzip(zipped_filename, unzipped_filename)
     case self.mime_type(zipped_filename)
     when "application/zip"
-      %x[ unzip -p #{zipped_filename} > #{unzipped_filename} ]
+      if zipped_filename.end_with?('.xlsx') # .xlsx IS a zipfile
+        %x[ cp #{zipped_filename} #{unzipped_filename} ]
+      else
+        %x[ unzip -p #{zipped_filename} > #{unzipped_filename} ]
+      end
     when "application/x-gzip"
       %x[ gzip -c -d #{zipped_filename} > #{unzipped_filename} ]
     when "text/plain"