Refactor temp directory methods into helper module

lib/directory_helper.rb

@@ -0,0 +1,22 @@
+module DirectoryHelper
+
+  def tmp_directory(prefix)
+    directory_cache[prefix] ||= begin
+      f = File.join( Rails.root, 'tmp', Time.now.strftime("#{prefix}%Y%m%d%H%M%S") )
+      FileUtils.mkdir_p(f) unless Dir[f].present?
+      f
+    end
+  end
+
+  def remove_tmp_directory(prefix)
+    tmp_directory_name = directory_cache[prefix] || ''
+    directory_cache.delete(prefix)
+    FileUtils.rm_rf(tmp_directory_name) if Dir[tmp_directory_name].present?
+  end
+
+  private
+  def directory_cache
+    @directory_cache ||= {}
+  end
+
+end

lib/export/json_encoder.rb

@@ -1,23 +1,18 @@
+require_dependency 'directory_helper'
+
 module Export
 
   class SchemaArgumentsError < RuntimeError; end
 
   class JsonEncoder
+    include DirectoryHelper
 
     def initialize
       @table_data = {}
     end
 
-    def tmp_directory
-      @tmp_directory ||= begin
-        f = File.join( Rails.root, 'tmp', Time.now.strftime('export%Y%m%d%H%M%S') )
-        Dir.mkdir(f) unless Dir[f].present?
-        f
-      end
-    end
-
     def json_output_stream
-      @json_output_stream ||= File.new( File.join( tmp_directory, 'tables.json' ), 'w+b' )
+      @json_output_stream ||= File.new( File.join( tmp_directory('export'), 'tables.json' ), 'w+b' )
     end
 
     def write_schema_info(args)
@@ -59,15 +54,12 @@ module Export
                                         :mode => :compat) )
       json_output_stream.close
 
-      @filenames = [File.join( tmp_directory, 'tables.json' )]
+      @filenames = [File.join( tmp_directory('export'), 'tables.json' )]
     end
 
     def filenames
       @filenames ||= []
     end
 
-    def cleanup_temp
-      FileUtils.rm_rf(tmp_directory) if Dir[tmp_directory].present?
-    end
   end
 end

lib/jobs/exporter.rb

@@ -75,7 +75,7 @@ module Jobs
       if @encoder
         @encoder.finish
         create_tar_file
-        @encoder.cleanup_temp
+        @encoder.remove_tmp_directory('export')
       end
     ensure
       Export.set_export_is_not_running

lib/jobs/importer.rb

@@ -1,6 +1,7 @@
 require_dependency 'import/json_decoder'
 require_dependency 'import/import'
 require_dependency 'import/adapter/base'
+require_dependency 'directory_helper'
 
 (Dir.entries(File.join( Rails.root, 'lib', 'import', 'adapter' )) - ['.', '..', 'base.rb']).each do |f|
   require_dependency "import/adapter/#{f}"
@@ -10,6 +11,7 @@ module Jobs
 
   class Importer < Jobs::Base
 
+    include DirectoryHelper
     sidekiq_options retry: false
 
     BACKUP_SCHEMA = 'backup'
@@ -67,23 +69,15 @@ module Jobs
         raise Import::FilenameMissingError
       else
         extract_files
-        @decoder = Import::JsonDecoder.new( File.join(tmp_directory, 'tables.json') )
+        @decoder = Import::JsonDecoder.new( File.join(tmp_directory('import'), 'tables.json') )
         Import.set_import_started
         Discourse.enable_maintenance_mode
       end
       self
     end
 
-    def tmp_directory
-      @tmp_directory ||= begin
-        f = File.join( Rails.root, 'tmp', Time.now.strftime('import%Y%m%d%H%M%S') )
-        Dir.mkdir(f) unless Dir[f].present?
-        f
-      end
-    end
-
     def extract_files
-      FileUtils.cd( tmp_directory ) do
+      FileUtils.cd( tmp_directory('import') ) do
         `tar xvzf #{@archive_filename} tables.json`
       end
     end
@@ -248,7 +242,7 @@ module Jobs
     def finish_import
       Import.set_import_is_not_running
       Discourse.disable_maintenance_mode
-      FileUtils.rm_rf(tmp_directory) if Dir[tmp_directory].present?
+      remove_tmp_directory('import')
 
       if @warnings.size > 0
         log "WARNINGS:"

spec/components/directory_helper_spec.rb

@@ -0,0 +1,35 @@
+require 'spec_helper'
+require_dependency 'directory_helper'
+
+describe DirectoryHelper do
+  class DummyClass
+    include DirectoryHelper
+  end
+  let(:helper) { DummyClass.new }
+
+  before do
+    helper.tmp_directory('prefix')
+    helper.tmp_directory('other_prefix')
+  end
+
+  after do
+    helper.remove_tmp_directory('prefix')
+    helper.remove_tmp_directory('other_prefix')
+  end
+
+  describe '#tmp_directory' do
+    it 'is memoized by prefix' do
+      helper.tmp_directory('prefix').should eq(helper.tmp_directory('prefix'))
+      helper.tmp_directory('prefix').should_not eq(helper.tmp_directory('other_prefix'))
+    end
+  end
+
+  describe '#remove_tmp_directory' do
+    it 'removes the prefixed directory from the filesystem' do
+      tmp_directory = helper.tmp_directory('prefix')
+      helper.remove_tmp_directory('prefix')
+
+      Dir[tmp_directory].should_not be_present
+    end
+  end
+end