Only cache attributes which need it for performance reasons. Closes #9767 [skaes]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7752 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 51 insertions, 0 deletions

diff --git a/activerecord/test/attribute_methods_test.rb b/activerecord/test/attribute_methods_test.rb
index f16b264c35..8646afdcb5 100755
--- a/activerecord/test/attribute_methods_test.rb
+++ b/activerecord/test/attribute_methods_test.rb
@@ -2,6 +2,7 @@ require 'abstract_unit'
 require 'fixtures/topic'
 
 class AttributeMethodsTest < Test::Unit::TestCase
+  fixtures :topics
   def setup
     @old_suffixes = ActiveRecord::Base.send(:attribute_method_suffixes).dup
     @target = Class.new(ActiveRecord::Base)
@@ -92,4 +93,54 @@ class AttributeMethodsTest < Test::Unit::TestCase
       end
     end
   end
+
+  def test_only_time_related_columns_are_meant_to_be_cached_by_default
+    expected = %w(datetime timestamp time date).sort
+    assert_equal expected, ActiveRecord::Base.attribute_types_cached_by_default.map(&:to_s).sort
+end
+
+  def test_declaring_attributes_as_cached_adds_them_to_the_attributes_cached_by_default
+    default_attributes = Topic.cached_attributes
+    Topic.cache_attributes :replies_count
+    expected = default_attributes + ["replies_count"]
+    assert_equal expected.sort, Topic.cached_attributes.sort
+    Topic.instance_variable_set "@cached_attributes", nil
+  end
+
+  def test_time_related_columns_are_actually_cached
+    column_types = %w(datetime timestamp time date).map(&:to_sym)
+    column_names = Topic.columns.select{|c| column_types.include?(c.type) }.map(&:name)
+
+    assert_equal column_names.sort, Topic.cached_attributes.sort
+    assert_equal time_related_columns_on_topic.sort, Topic.cached_attributes.sort
+  end
+
+  def test_accessing_cached_attributes_caches_the_converted_values_and_nothing_else
+    t = topics(:first)
+    cache = t.instance_variable_get "@attributes_cache"
+
+    assert_not_nil cache
+    assert cache.empty?
+
+    all_columns = Topic.columns.map(&:name)
+    cached_columns = time_related_columns_on_topic
+    uncached_columns =  all_columns - cached_columns
+
+    all_columns.each do |attr_name|
+      attribute_gets_cached = Topic.cache_attribute?(attr_name)
+      val = t.send attr_name unless attr_name == "type"
+      if attribute_gets_cached
+        assert cached_columns.include?(attr_name)
+        assert_equal val, cache[attr_name]
+      else
+        assert uncached_columns.include?(attr_name)
+        assert !cache.include?(attr_name)
+      end
+    end
+  end
+
+  private
+  def time_related_columns_on_topic
+    Topic.columns.select{|c| [:time, :date, :datetime, :timestamp].include?(c.type)}.map(&:name)
+  end
 end