Add basic caching

test/caching_test.rb

@@ -0,0 +1,97 @@
+require "test_helper"
+
+class CachingTest < ActiveModel::TestCase
+  class NullStore
+    def fetch(key)
+      return store[key] if store[key]
+
+      store[key] = yield
+    end
+
+    def clear
+      store.clear
+    end
+
+    def store
+      @store ||= {}
+    end
+
+    def read(key)
+      store[key]
+    end
+  end
+
+  class Programmer
+    def name
+      'Adam'
+    end
+
+    def skills
+      %w(ruby)
+    end
+
+    def cache_key
+      name
+    end
+
+    def read_attribute_for_serialization(name)
+      send name
+    end
+  end
+
+  def test_serializers_have_a_cache_store
+    ActiveModel::Serializer.cache = NullStore.new
+
+    assert ActiveModel::Serializer.cache
+  end
+
+  def test_serializers_can_enable_caching
+    serializer = Class.new(ActiveModel::Serializer) do
+      cache true
+    end
+
+    assert serializer.perform_caching
+  end
+
+  def test_serializers_cache_serializable_hash
+    serializer = Class.new(ActiveModel::Serializer) do
+      cache true
+      attributes :name, :skills
+
+      def self.to_s
+        'serializer'
+      end
+    end
+
+    serializer.cache = NullStore.new
+    instance = serializer.new Programmer.new
+
+    instance.to_json
+
+    assert_equal({
+      :name => 'Adam',
+      :skills => ['ruby'],
+    }, serializer.cache.read('serializer/Adam/serializable-hash'))
+  end
+
+  def test_serializers_cache_to_json
+    serializer = Class.new(ActiveModel::Serializer) do
+      cache true
+      attributes :name, :skills
+
+      def self.to_s
+        'serializer'
+      end
+    end
+
+    serializer.cache = NullStore.new
+    instance = serializer.new Programmer.new
+
+    instance.to_json
+
+    assert_equal({
+      :name => 'Adam',
+      :skills => ['ruby'],
+    }.to_json, serializer.cache.read('serializer/Adam/to-json'))
+  end
+end