Add support for atime

lib/fakefs/fake/dir.rb

@@ -1,13 +1,14 @@
 module FakeFS
   class FakeDir < Hash
     attr_accessor :name, :parent
-    attr_reader :ctime, :mtime
+    attr_reader :ctime, :mtime, :atime
 
     def initialize(name = nil, parent = nil)
       @name   = name
       @parent = parent
       @ctime  = Time.now
       @mtime  = @ctime
+      @atime  = @ctime
     end
 
     def entry

lib/fakefs/fake/file.rb

@@ -1,6 +1,6 @@
 module FakeFS
   class FakeFile
-    attr_accessor :name, :parent, :content, :mtime
+    attr_accessor :name, :parent, :content, :mtime, :atime
     attr_reader :ctime
 
     class Inode
@@ -34,6 +34,7 @@ module FakeFS
       @inode  = Inode.new(self)
       @ctime  = Time.now
       @mtime  = @ctime
+      @atime  = @ctime
     end
 
     attr_accessor :inode

lib/fakefs/file.rb

@@ -69,9 +69,18 @@ module FakeFS
       end
     end
 
+    def self.atime(path)
+      if exists?(path)
+        FileSystem.find(path).atime
+      else
+        raise Errno::ENOENT
+      end
+    end
+
     def self.utime(atime, mtime, *paths)
       paths.each do |path|
         if exists?(path)
+          FileSystem.find(path).atime = atime
           FileSystem.find(path).mtime = mtime
         else
           raise Errno::ENOENT
@@ -143,6 +152,7 @@ module FakeFS
     def self.read(path)
       file = new(path)
       if file.exists?
+        FileSystem.find(path).atime = Time.now
         file.read
       else
         raise Errno::ENOENT
@@ -225,7 +235,7 @@ module FakeFS
     end
 
     class Stat
-      attr_reader :ctime, :mtime
+      attr_reader :ctime, :mtime, :atime
 
       def initialize(file, __lstat = false)
         if !File.exists?(file)
@@ -237,6 +247,7 @@ module FakeFS
         @__lstat   = __lstat
         @ctime     = @fake_file.ctime
         @mtime     = @fake_file.mtime
+        @atime     = @fake_file.atime
       end
 
       def symlink?
@@ -326,7 +337,7 @@ module FakeFS
     end
 
     def atime
-      raise NotImplementedError
+      self.class.atime(@path)
     end
 
     def chmod(mode_int)

test/fakefs_test.rb

@@ -495,27 +495,45 @@ class FakeFSTest < Test::Unit::TestCase
     assert File.ctime('foo').is_a?(Time)
   end
 
-  def test_ctime_and_mtime_are_equal_for_new_files
+  def test_raises_error_on_atime_if_file_does_not_exist
+    assert_raise Errno::ENOENT do
+      File.atime('file.txt')
+    end
+  end
+
+  def test_can_return_atime_on_existing_file
+    File.open("foo", "w") { |f| f << "some content" }
+    assert File.atime('foo').is_a?(Time)
+  end
+
+  def test_ctime_mtime_and_atime_are_equal_for_new_files
     File.open("foo", "w") { |f| f << "some content" }
     ctime = File.ctime("foo")
     mtime = File.mtime("foo")
+    atime = File.atime("foo")
     assert ctime.is_a?(Time)
     assert mtime.is_a?(Time)
+    assert atime.is_a?(Time)
     assert_equal ctime, mtime
+    assert_equal ctime, atime
 
     File.open("foo", "r") do |f|
       assert_equal ctime, f.ctime
       assert_equal mtime, f.mtime
+      assert_equal atime, f.atime
     end
   end
 
-  def test_ctime_and_mtime_are_equal_for_new_directories
+  def test_ctime_mtime_and_atime_are_equal_for_new_directories
     FileUtils.mkdir_p("foo")
     ctime = File.ctime("foo")
     mtime = File.mtime("foo")
+    atime = File.atime("foo")
     assert ctime.is_a?(Time)
     assert mtime.is_a?(Time)
+    assert atime.is_a?(Time)
     assert_equal ctime, mtime
+    assert_equal ctime, atime
   end
 
   def test_file_ctime_is_equal_to_file_stat_ctime
@@ -538,6 +556,16 @@ class FakeFSTest < Test::Unit::TestCase
     assert_equal File.stat("foo").mtime, File.mtime("foo")
   end
 
+  def test_file_atime_is_equal_to_file_stat_atime
+    File.open("foo", "w") { |f| f << "some content" }
+    assert_equal File.stat("foo").atime, File.atime("foo")
+  end
+
+  def test_directory_atime_is_equal_to_directory_stat_atime
+    FileUtils.mkdir_p("foo")
+    assert_equal File.stat("foo").atime, File.atime("foo")
+  end
+
   def test_utime_raises_error_if_path_does_not_exist
     assert_raise Errno::ENOENT do
       File.utime(Time.now, Time.now, '/path/to/file.txt')
@@ -552,6 +580,7 @@ class FakeFSTest < Test::Unit::TestCase
     end
     File.utime(time, time, path)
     assert_equal time, File.mtime('file.txt')
+    assert_equal time, File.atime('file.txt')
   end
 
   def test_utime_returns_number_of_paths
@@ -564,6 +593,21 @@ class FakeFSTest < Test::Unit::TestCase
     assert_equal 2, File.utime(Time.now, Time.now, path1, path2)
   end
 
+  def test_file_a_time_updated_when_file_is_read
+    old_atime = Time.now - 300
+
+    path = "file.txt"
+    File.open(path, "w") do |f|
+      f << "Hello"
+    end
+
+    File.utime(old_atime, File.mtime(path), path)
+
+    assert_equal File.atime(path), old_atime
+    File.read(path)
+    assert File.atime(path) != old_atime
+  end
+
   def test_can_read_with_File_readlines
     path = 'file.txt'
     File.open(path, 'w') do |f|