From 48a579de0e4698f52f8c5816f1948ddf96d1a8c0 Mon Sep 17 00:00:00 2001
From: Jay Pignata <john.pignata@gmail.com>
Date: Sat, 15 May 2010 22:17:35 +0100
Subject: [PATCH] Adding NullStore to ActiveSupport::Cache

---
 activesupport/lib/active_support/cache.rb          |    1 +
 .../lib/active_support/cache/null_store.rb         |   35 +++++++++++++++++++
 activesupport/test/caching_test.rb                 |   36 ++++++++++++++++++++
 3 files changed, 72 insertions(+), 0 deletions(-)
 create mode 100644 activesupport/lib/active_support/cache/null_store.rb

diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 2605a3f..d81f2bd 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -18,6 +18,7 @@ module ActiveSupport
     autoload :MemCacheStore, 'active_support/cache/mem_cache_store'
     autoload :SynchronizedMemoryStore, 'active_support/cache/synchronized_memory_store'
     autoload :CompressedMemCacheStore, 'active_support/cache/compressed_mem_cache_store'
+    autoload :NullStore, 'active_support/cache/null_store'
 
     EMPTY_OPTIONS = {}.freeze
 
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 0000000..79e085a
--- /dev/null
+++ b/activesupport/lib/active_support/cache/null_store.rb
@@ -0,0 +1,35 @@
+module ActiveSupport
+  module Cache
+    # A dummy cache store implementation for testing and debugging purposes. When configured, calls to
+    # Rails.cache will be logged but reading and writing from the cache will be disabled.
+    class NullStore < Store
+      def read_entry(key, options)
+        nil
+      end
+
+      def write_entry(key, entry, options)
+        entry
+      end
+
+      def delete(name, options = nil)
+        super do
+          nil
+        end
+      end
+
+      def exist?(name, options = nil)
+        super do
+          false
+        end
+      end
+
+      def increment(name, amount = 1, options = nil)
+        nil
+      end
+
+      def decrement(name, amount = 1, options=nil)
+        nil
+      end
+    end
+  end
+end
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index d9ff120..6061385 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -596,6 +596,42 @@ uses_memcached 'memcached backed store' do
   end
 end
 
+class NullStoreTest < ActiveSupport::TestCase
+  def setup
+    @cache = ActiveSupport::Cache.lookup_store(:null_store)
+  end
+
+  def test_write
+    @cache.write('foo', 'bar')
+    @cache.write('baz', {:a => 'b'})
+    @cache.write('foz', 2)
+
+    assert_nil @cache.fetch('foo')
+    assert_nil @cache.fetch('baz')
+    assert_nil @cache.fetch('foz')
+  end
+
+  def test_fetch
+    assert_equal 'baz', @cache.fetch('foo') { 'baz' }
+    assert_equal 'bar', @cache.fetch('foo') { 'bar' }
+  end
+
+  def test_increment
+    @cache.write('foo', 1, :raw => true)
+    assert_nil @cache.increment('foo')
+  end
+
+  def test_decrement
+    @cache.write('foo', 3, :raw => true)
+    assert_nil @cache.decrement('foo')
+  end
+
+  def test_exist
+    @cache.write('foo', 'bar')
+    assert !@cache.exist?('foo')
+  end
+end
+
 class CacheStoreLoggerTest < ActiveSupport::TestCase
   def setup
     @cache = ActiveSupport::Cache.lookup_store(:memory_store)
-- 
1.7.1