Add FileTest#exist? Swap out FileTest for FakeFS::FileTest. Closes #14

lib/fakefs/base.rb

@@ -1,4 +1,5 @@
 RealFile = File
+RealFileTest = FileTest
 RealFileUtils = FileUtils
 RealDir = Dir
 RealFileUtils::Dir = RealDir
@@ -9,20 +10,24 @@ def self.activate!
     Object.class_eval do
       remove_const(:Dir)
       remove_const(:File)
+      remove_const(:FileTest)
       remove_const(:FileUtils)
       const_set(:Dir, FakeFS::Dir)
       const_set(:File, FakeFS::File)
       const_set(:FileUtils, FakeFS::FileUtils)
+      const_set(:FileTest,  FakeFS::FileTest)
     end
   end
 
   def self.deactivate!
     Object.class_eval do
       remove_const(:Dir)
       remove_const(:File)
+      remove_const(:FileTest)
       remove_const(:FileUtils)
       const_set(:Dir, RealDir)
       const_set(:File, RealFile)
+      const_set(:FileTest, RealFileTest)
       const_set(:FileUtils, RealFileUtils)
     end
   end

lib/fakefs/file_test.rb

@@ -0,0 +1,7 @@
+module FakeFS
+  class FileTest
+    def self.exist?(file_name)
+      File.exist?(file_name)
+    end
+  end
+end

lib/fakefs/safe.rb

@@ -7,5 +7,6 @@
 require 'fakefs/file_system'
 require 'fakefs/fileutils'
 require 'fakefs/file'
+require 'fakefs/file_test'
 require 'fakefs/dir'
 

test/fakefs_test.rb

@@ -1336,6 +1336,21 @@ def test_should_have_constants_inherited_from_descending_from_io
     assert_equal IO::SEEK_SET, File::SEEK_SET
   end
 
+  def test_filetest_exists_return_correct_values
+    FileUtils.mkdir_p("/path/to/dir")
+    assert FileTest.exist?("/path/to/")
+
+    FileUtils.rmdir("/path/to/dir")
+    assert !FileTest.exist?("/path/to/dir")
+  end
+
+  def pathname_exists_returns_correct_value
+    FileUtils.touch "foo"
+    assert Pathname.new("foo").exist?
+
+    assert !Pathname.new("bar").exist?
+  end
+
   def here(fname)
     RealFile.expand_path(RealFile.dirname(__FILE__)+'/'+fname)
   end