3 files changed, 109 insertions, 6 deletions
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 07f5fcdeb3..9711ed6f73 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -16,6 +16,7 @@ module ActiveSupport
     autoload :FileStore, 'active_support/cache/file_store'
     autoload :MemoryStore, 'active_support/cache/memory_store'
     autoload :MemCacheStore, 'active_support/cache/mem_cache_store'
+    autoload :NullStore, 'active_support/cache/null_store'
 
     # These options mean something to all cache implementations. Individual cache
     # implementations may support additional options.
diff --git a/activesupport/lib/active_support/cache/null_store.rb b/activesupport/lib/active_support/cache/null_store.rb
new file mode 100644
index 0000000000..4427eaafcd
--- /dev/null
+++ b/activesupport/lib/active_support/cache/null_store.rb
@@ -0,0 +1,44 @@
+module ActiveSupport
+  module Cache
+    # A cache store implementation which doesn't actually store anything. Useful in
+    # development and test environments where you don't want caching turned on but
+    # need to go through the caching interface.
+    #
+    # This cache does implement the local cache strategy, so values will actually
+    # be cached inside blocks that utilize this strategy. See
+    # ActiveSupport::Cache::Strategy::LocalCache for more details.
+    class NullStore < Store
+      def initialize(options = nil)
+        super(options)
+        extend Strategy::LocalCache
+      end
+
+      def clear(options = nil)
+      end
+
+      def cleanup(options = nil)
+      end
+
+      def increment(name, amount = 1, options = nil)
+      end
+
+      def decrement(name, amount = 1, options = nil)
+      end
+
+      def delete_matched(matcher, options = nil)
+      end
+
+      protected
+        def read_entry(key, options) # :nodoc:
+        end
+
+        def write_entry(key, entry, options) # :nodoc:
+          true
+        end
+
+        def delete_entry(key, options) # :nodoc:
+          false
+        end
+    end
+  end
+end
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index 5d7464c623..ab29ddecc5 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -218,7 +218,7 @@ module CacheStoreBehavior
     @cache.write('fud', 'biz')
     assert_equal({"foo" => "bar", "fu" => "baz"}, @cache.read_multi('foo', 'fu'))
   end
-  
+
   def test_read_multi_with_expires
     @cache.write('foo', 'bar', :expires_in => 0.001)
     @cache.write('fu', 'baz')
@@ -576,12 +576,12 @@ class FileStoreTest < ActiveSupport::TestCase
     key = @cache_with_pathname.send(:key_file_path, "views/index?id=1")
     assert_equal "views/index?id=1", @cache_with_pathname.send(:file_path_key, key)
   end
-  
+
   # Because file systems have a maximum filename size, filenames > max size should be split in to directories
   # If filename is 'AAAAB', where max size is 4, the returned path should be AAAA/B
   def test_key_transformation_max_filename_size
     key = "#{'A' * ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE}B"
-    path = @cache.send(:key_file_path, key)    
+    path = @cache.send(:key_file_path, key)
     assert path.split('/').all? { |dir_name| dir_name.size <= ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE}
     assert_equal 'B', File.basename(path)
   end
@@ -689,14 +689,14 @@ uses_memcached 'memcached backed store' do
       cache.write("foo", 2)
       assert_equal "2", cache.read("foo")
     end
-    
+
     def test_raw_values_with_marshal
       cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, :raw => true)
       cache.clear
       cache.write("foo", Marshal.dump([]))
-      assert_equal [], cache.read("foo")      
+      assert_equal [], cache.read("foo")
     end
-    
+
     def test_local_cache_raw_values
       cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, :raw => true)
       cache.clear
@@ -717,6 +717,64 @@ uses_memcached 'memcached backed store' do
   end
 end
 
+class NullStoreTest < ActiveSupport::TestCase
+  def setup
+    @cache = ActiveSupport::Cache.lookup_store(:null_store)
+  end
+
+  def test_clear
+    @cache.clear
+  end
+
+  def test_cleanup
+    @cache.cleanup
+  end
+
+  def test_write
+    assert_equal true, @cache.write("name", "value")
+  end
+
+  def test_read
+    @cache.write("name", "value")
+    assert_nil @cache.read("name")
+  end
+
+  def test_delete
+    @cache.write("name", "value")
+    assert_equal false, @cache.delete("name")
+  end
+
+  def test_increment
+    @cache.write("name", 1, :raw => true)
+    assert_nil @cache.increment("name")
+  end
+
+  def test_decrement
+    @cache.write("name", 1, :raw => true)
+    assert_nil @cache.increment("name")
+  end
+
+  def test_delete_matched
+    @cache.write("name", "value")
+    @cache.delete_matched(/name/)
+  end
+
+  def test_local_store_strategy
+    @cache.with_local_cache do
+      @cache.write("name", "value")
+      assert_equal "value", @cache.read("name")
+      @cache.delete("name")
+      assert_nil @cache.read("name")
+      @cache.write("name", "value")
+    end
+    assert_nil @cache.read("name")
+  end
+
+  def test_setting_nil_cache_store
+    assert ActiveSupport::Cache.lookup_store.class.name, ActiveSupport::Cache::NullStore.name
+  end
+end
+
 class CacheStoreLoggerTest < ActiveSupport::TestCase
   def setup
     @cache = ActiveSupport::Cache.lookup_store(:memory_store)