start adding basic tests for fakefs

lib/fakefs.rb

@@ -1,4 +1,6 @@
-module FakeFS
+require 'fileutils'
+
+class FakeFS
   module FileUtils
     extend self
 
@@ -41,13 +43,17 @@ module FakeFS
     end
 
     def self.expand_path(path)
-      ::File.expand_path(path)
+      RealFile.expand_path(path)
     end
 
     def self.readlink(path)
       symlink = FileSystem.find(path)
       FileSystem.find(symlink.target).to_s
     end
+
+    def self.dirname(path)
+      RealFile.dirname(path)
+    end
   end
 
   class Dir
@@ -60,8 +66,52 @@ module FakeFS
     end
   end
 
-  module FileSystem
+
-    extend self
+  class MockDir < Hash
+    attr_accessor :name, :parent
+
+    def initialize(name = nil, parent = nil)
+      @name = name
+      @parent = parent
+    end
+
+    def files
+      values
+    end
+
+    def entry
+      self
+    end
+
+    def to_s
+      if parent && parent.to_s != '.'
+        parent.to_s + '/' + name
+      else
+        name
+      end
+    end
+  end
+
+  class MockSymlink
+    attr_accessor :name, :target
+    alias_method  :to_s, :name
+
+    def initialize(target)
+      @target = target
+    end
+
+    def inspect
+      "symlink(#{target.split('/').last})"
+    end
+
+    def entry
+      FileSystem.find(target)
+    end
+
+    def method_missing(*args, &block)
+      entry.send(*args, &block)
+    end
+  end
 
   def fs
     @fs ||= MockDir.new('.')
@@ -107,51 +157,18 @@ module FakeFS
   def path_parts(path)
     path.split(File::PATH_SEPARATOR)
   end
-  end
-
-  class MockDir < Hash
-    attr_accessor :name, :parent
-
-    def initialize(name = nil, parent = nil)
-      @name = name
-      @parent = parent
-    end
-
-    def entry
-      self
-    end
-
-    def to_s
-      if parent && parent.to_s != '.'
-        parent.to_s + '/' + name
-      else
-        name
-      end
-    end
-  end
-
-  class MockSymlink
-    attr_accessor :name, :target
-    alias_method  :to_s, :name
-
-    def initialize(target)
-      @target = target
-    end
-
-    def inspect
-      "symlink(#{target.split('/').last})"
-    end
-
-    def entry
-      FileSystem.find(target)
-    end
 
   def method_missing(*args, &block)
-      entry.send(*args, &block)
+    fs.send(*args, &block)
-    end
   end
+
+  FileSystem = FakeFS.new('.')
 end
 
+RealFile = File
+RealFileUtils = FileUtils
+RealDir = Dir
+
 Object.class_eval do
   remove_const(:Dir)
   remove_const(:File)

test/fake_fs.rb

@@ -0,0 +1,15 @@
+$LOAD_PATH.unshift File.join(File.dirname(__FILE__), '..', 'lib')
+require 'fakefs'
+require 'test/unit'
+
+class FakeFSTest < Test::Unit::TestCase
+  def test_can_be_initialized_empty
+    fs = FakeFS.new('.')
+    assert_equal 0, fs.files.size
+  end
+
+  def test_can_be_initialized_with_an_existing_directory
+    fs = FakeFS.new(File.expand_path(File.dirname(__FILE__)))
+    assert_equal 1, fs.files.size
+  end
+end