From 3a5098092cccbaeaae36c35eee66f07405483305 Mon Sep 17 00:00:00 2001
From: Scott Taylor <scott@railsnewbie.com>
Date: Wed, 30 Sep 2009 03:28:33 -0400
Subject: [PATCH] Raise an IOError when a file is read in a write-only mode.

---
 lib/fakefs/file.rb  |  7 ++++++-
 test/fakefs_test.rb | 20 ++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/lib/fakefs/file.rb b/lib/fakefs/file.rb
index 3f5b048..fdc8199 100644
--- a/lib/fakefs/file.rb
+++ b/lib/fakefs/file.rb
@@ -116,7 +116,8 @@ module FakeFS
     end
 
     def read
-      raise IOError.new('closed stream') unless @open
+      raise IOError, 'closed stream' unless @open
+      raise IOError, 'not opened for reading' if write_only?
       @file.content
     end
 
@@ -172,5 +173,9 @@ module FakeFS
         @file = FileSystem.add(path, FakeFile.new)
       end
     end
+
+    def write_only?
+      @mode == WRITE_ONLY || @mode == APPEND_WRITE_ONLY
+    end
   end
 end
diff --git a/test/fakefs_test.rb b/test/fakefs_test.rb
index e270833..1d2914c 100644
--- a/test/fakefs_test.rb
+++ b/test/fakefs_test.rb
@@ -146,6 +146,26 @@ class FakeFSTest < Test::Unit::TestCase
     assert File.exists?("foo")
   end
 
+  def test_file_in_write_only_raises_error_when_reading
+    FileUtils.touch("foo")
+
+    f = File.open("foo", "w")
+
+    assert_raises(IOError) do
+      f.read
+    end
+  end
+
+  def test_file_in_append_write_only_raises_error_when_reading
+    FileUtils.touch("foo")
+
+    f = File.open("foo", "a")
+
+    assert_raises(IOError) do
+      f.read
+    end
+  end
+
   def test_can_read_files_once_written
     path = '/path/to/file.txt'
     File.open(path, 'w') do |f|