From a8245db14599eccdc106d6bf17d40a53deed2783 Mon Sep 17 00:00:00 2001
From: Scott Taylor <scott@railsnewbie.com>
Date: Wed, 30 Sep 2009 02:57:10 -0400
Subject: [PATCH] Raise an error when giving File.open an illegal access mode. 
 Set default mode for File.open to READ_ONLY

---
 lib/fakefs/file.rb  | 10 +++++++++-
 test/fakefs_test.rb |  8 ++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/fakefs/file.rb b/lib/fakefs/file.rb
index a14c6b9..db14ef3 100644
--- a/lib/fakefs/file.rb
+++ b/lib/fakefs/file.rb
@@ -100,7 +100,9 @@ module FakeFS
     end
 
     attr_reader :path
-    def initialize(path, mode = nil, perm = nil)
+    def initialize(path, mode = READ_ONLY, perm = nil)
+      check_mode(mode)
+
       @path = path
       @mode = mode
       @file = FileSystem.find(path)
@@ -146,5 +148,11 @@ module FakeFS
     def read_only?
       @mode == READ_ONLY
     end
+
+    def check_mode(mode)
+      if !MODES.include?(mode)
+        raise ArgumentError, "illegal access mode #{mode}"
+      end
+    end
   end
 end
diff --git a/test/fakefs_test.rb b/test/fakefs_test.rb
index 5b9d69d..22b08cc 100644
--- a/test/fakefs_test.rb
+++ b/test/fakefs_test.rb
@@ -106,6 +106,14 @@ class FakeFSTest < Test::Unit::TestCase
     end
   end
 
+  def test_file_opens_in_invalid_mode
+    FileUtils.touch("foo")
+
+    assert_raises(ArgumentError) do
+      File.open("foo", "an_illegal_mode")
+    end
+  end
+
   def test_can_read_files_once_written
     path = '/path/to/file.txt'
     File.open(path, 'w') do |f|