get_title_and_rename增加测试，让代码更干净

get_title_and_rename.rb

@@ -1,9 +1,10 @@
 # -*- coding: utf-8 -*-
 require 'find'
 require 'fileutils'
+require 'minitest/autorun'
 
+# USAGE: ruby -w script.rb inputfolder 
 # !! update filename in place !!
-# usage: ruby -w script.rb inputfolder
 # files in inputfolder will be renamed accordingly
 
 path = File.expand_path ARGV[0]
@@ -14,24 +15,42 @@
   filepath = File.dirname file
   filename = File.basename(file, '.txt')
   File.open(file, 'r') do |l|
-    title = l.gets
+    title = l.gets # 默认第一行就是题目 且题目格式是 title: some title
     # The (?:…) construct provides grouping without capturing.
     #if m = title.match(/The Project Gutenberg (?:EBook|etext) of(.+)/i)
-    $realtitle = title.split(':')[1] # first line is titile, format,  title: this is title
-
-    if $realtitle
+    $realtitle = title.iyc_get_title
+    if $realtitle # 也许有的文件就没有 title: some title 这行 必须得确认 #realtitle 不是 nil
       $realtitle = $realtitle.strip.tr(',;:', '').gsub(/\s+/, '_').gsub(/\n|\r/, '').downcase
     else
-      $realtitle = ''
+      $realtitle = '' 
     end
   end
-#    p $realtitle
-  p filepath
   newfilename = filename.downcase + '_' + $realtitle + '.txt'
   newfilename = newfilename.gsub(/_+\./, '.') # handle "An_Essay_on_Profits_.txt"
   p "rename #{filename} to #{newfilename}"
-  if filename + '.txt' != newfilename
+  if filename + '.txt' != newfilename  # 如果将文件改名为它自身会报错，比如 mv file file 报错的
     FileUtils.mv(file, "#{filepath}/#{newfilename}") 
   end # can't get title for some files so newfilename would be equal to filename, skip those!
 end
 
+class String
+  def iyc_get_title
+    self.split(':')[1..-1].join.strip
+    # array[1..-1] to cater to special case Title: title with colon: a true story
+  end
+  def iyc_title_to_filename
+    self.strip.tr(',;:!', '').gsub(/\s+/, '_').gsub(/\n|\r/, '').downcase
+  end
+end
+
+# tests
+
+class TestSanitize < MiniTest::Unit::TestCase
+  def test_iyc_get_title
+    assert_equal 'The History Of The Decline And Fall Of The Roman Empire', 'Title: The History Of The Decline And Fall Of The Roman Empire'.iyc_get_title, 'test case 1'
+    assert_equal 'Les Miserables', 'Title: Les Miserables'.iyc_get_title, 'test case 2'
+  end
+  def test_iyc_title_to_filename
+    assert_equal 'some_strange_characters', 'Title: some; strange: characters!'.iyc_get_title.iyc_title_to_filename, 'test case 3'
+  end
+end