From 076ef40678c7c4dba1edca0ef420fe4970d7676d Mon Sep 17 00:00:00 2001
From: Aaron Suggs <aaron@ktheory.com>
Date: Mon, 11 Jan 2010 19:55:01 -0500
Subject: [PATCH] Add File.rename (a primitive of FileUtils.mv).  Closes #29

---
 lib/fakefs/file.rb  | 17 ++++++++++++++
 test/fakefs_test.rb | 55 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/lib/fakefs/file.rb b/lib/fakefs/file.rb
index 1588096..4711186 100644
--- a/lib/fakefs/file.rb
+++ b/lib/fakefs/file.rb
@@ -148,6 +148,23 @@ module FakeFS
       read(path).split("\n")
     end
 
+    def self.rename(source, dest)
+      if directory?(source) && file?(dest)
+        raise Errno::ENOTDIR, "Not a directory - #{source} or #{dest}"
+      elsif file?(source) && directory?(dest)
+        raise Errno::EISDIR, "Is a directory - #{source} or #{dest}"
+      end
+
+      if target = FileSystem.find(source)
+        FileSystem.add(dest, target.entry.clone)
+        FileSystem.delete(source)
+      else
+        raise Errno::ENOENT,  "No such file or directory - #{source} or #{dest}"
+      end
+
+      0
+    end
+
     def self.link(source, dest)
       if directory?(source)
         raise Errno::EPERM, "Operation not permitted - #{source} or #{dest}"
diff --git a/test/fakefs_test.rb b/test/fakefs_test.rb
index 6411bd9..473557d 100644
--- a/test/fakefs_test.rb
+++ b/test/fakefs_test.rb
@@ -1267,6 +1267,61 @@ class FakeFSTest < Test::Unit::TestCase
     assert Dir.tmpdir == "/tmp"
   end
 
+  def test_rename_renames_a_file
+    FileUtils.touch("/foo")
+    File.rename("/foo", "/bar")
+    assert File.file?("/bar")
+  end
+
+  def test_rename_returns
+    FileUtils.touch("/foo")
+    assert_equal 0, File.rename("/foo", "/bar")
+  end
+
+  def test_rename_renames_two_files
+    FileUtils.touch("/foo")
+    FileUtils.touch("/bar")
+    File.rename("/foo", "/bar")
+    assert File.file?("/bar")
+
+  end
+
+  def test_rename_renames_a_directories
+    Dir.mkdir("/foo")
+    File.rename("/foo", "/bar")
+    assert File.directory?("/bar")
+  end
+
+  def test_rename_renames_two_directories
+    Dir.mkdir("/foo")
+    Dir.mkdir("/bar")
+    File.rename("/foo", "/bar")
+    assert File.directory?("/bar")
+  end
+
+  def test_rename_file_to_directory_raises_error
+    FileUtils.touch("/foo")
+    Dir.mkdir("/bar")
+    assert_raises(Errno::EISDIR) do
+      File.rename("/foo", "/bar")
+    end
+  end
+
+  def test_rename_directory_to_file_raises_error
+    Dir.mkdir("/foo")
+    FileUtils.touch("/bar")
+    assert_raises(Errno::ENOTDIR) do
+      File.rename("/foo", "/bar")
+    end
+  end
+
+
+  def test_rename_with_missing_source_raises_error
+    assert_raises(Errno::ENOENT) do
+      File.rename("/no_such_file", "/bar")
+    end
+  end
+
   def test_hard_link_creates_file
     FileUtils.touch("/foo")