Ensure that every method in IO and File (RealFile) is in FakeFS::File (since File < IO). raise NotImplemenetedErrors for methods which have not yet been implemented.

lib/fakefs/file.rb

@@ -229,6 +229,66 @@ module FakeFS
 
     alias_method :tell=, :pos=
 
+    def ioctl(integer_cmd, arg)
+      raise NotImplementedError
+    end
+
+    def read_nonblock(maxlen, outbuf = nil)
+      raise NotImplementedError
+    end
+
+    def stat
+      raise NotImplementedError
+    end
+
+    def sysseek(offset, whence = SEEK_SET)
+      raise NotImplementedError
+    end
+
+    def to_i
+      raise NotImplementedError
+    end
+
+    def to_io
+      raise NotImplementedError
+    end
+
+    def write_nonblock(string)
+      raise NotImplementedError
+    end
+
+    def readpartial(maxlen, outbuf = nil)
+      raise NotImplementedError
+    end
+
+    def atime
+      raise NotImplementedError
+    end
+
+    def chmod(mode_int)
+      raise NotImplementedError
+    end
+
+    def chown(owner_int, group_int)
+      raise NotImplementedError
+    end
+
+    def ctime
+      raise NotImplementedError
+    end
+
+    def flock(locking_constant)
+      raise NotImplementedError
+    end
+
+    def lstat
+      raise NotImplementedError
+    end
+
+    def mtime
+      raise NotImplementedError
+    end
+
   private
 
     def check_modes!

test/fakefs_test.rb

@@ -487,6 +487,12 @@ class FakeFSTest < Test::Unit::TestCase
     assert_equal 1, fp.pos
   end
 
+  RealFile.instance_methods.each do |method_name|
+    define_method "test_should_have_method_#{method_name}_from_io_class" do
+      assert File.instance_methods.include?(method_name)
+    end
+  end
+
   def test_chdir_changes_directories_like_a_boss
     # I know memes!
     FileUtils.mkdir_p '/path'