add file#split

lib/fakefs/file.rb

@@ -215,6 +215,10 @@ module FakeFS
       File::Stat.new(file, true)
     end
 
+    def self.split(path)
+      return RealFile.split(path)
+    end
+
     class Stat
       attr_reader :ctime, :mtime
 

test/fakefs_test.rb

@@ -3,6 +3,14 @@ require "test_helper"
 class FakeFSTest < Test::Unit::TestCase
   include FakeFS
 
+  def test_split
+    assert File.respond_to? :split
+    filename = "/this/is/what/we/expect.txt"
+    path,filename = File.split(filename)
+    assert_equal path, "/this/is/what/we"
+    assert_equal filename, "expect.txt"
+  end
+
   def setup
     FakeFS.activate!
     FileSystem.clear