Improved error handling for Dir.delete and Dir.entries

This better matches the behavior of Ruby 1.8 and 1.9

(Closes #91)

lib/fakefs/dir.rb

@@ -65,12 +65,13 @@ module FakeFS
     end
 
     def self.delete(string)
-      raise SystemCallError, "No such file or directory - #{string}" unless FileSystem.find(string).values.empty?
+      raise Errno::ENOENT, "No such file or directory - #{string}" unless FileSystem.find(string)
+      raise Errno::ENOTEMPTY, "Directory not empty - #{string}" unless FileSystem.find(string).values.empty?
       FileSystem.delete(string)
     end
 
     def self.entries(dirname)
-      raise SystemCallError, dirname unless FileSystem.find(dirname)
+      raise Errno::ENOENT, "No such file or directory - #{dirname}" unless FileSystem.find(dirname)
       Dir.new(dirname).map { |file| File.basename(file) }
     end
 

test/fakefs_test.rb

@@ -1211,11 +1211,17 @@ class FakeFSTest < Test::Unit::TestCase
       FileUtils.touch("/this/path/should/be/here/#{f}")
     end
 
-    assert_raises(SystemCallError) do
+    assert_raises(Errno::ENOTEMPTY) do
       Dir.delete('/this/path/should/be/here')
     end
   end
 
+  def test_directory_class_delete_does_not_work_if_dir_path_cannot_be_found
+    assert_raises(Errno::ENOENT) do
+      Dir.delete('/this/path/should/not/be/here')
+    end
+  end
+
   def test_directory_entries
     test = ['.', '..', 'file_1', 'file_2', 'file_3', 'file_4', 'file_5' ]
 
@@ -1244,6 +1250,12 @@ class FakeFSTest < Test::Unit::TestCase
     test.each { |t| assert yielded.include?(t) }
   end
 
+  def test_directory_entries_does_not_work_if_dir_path_cannot_be_found
+    assert_raises(Errno::ENOENT) do
+      Dir.delete('/this/path/should/not/be/here')
+    end
+  end
+
   def test_directory_foreach
     test = ['.', '..', 'file_1', 'file_2', 'file_3', 'file_4', 'file_5' ]