Separate out ActiveModelSerializers::Model caching concerns

Author: bf4

lib/active_model/serializer/lint.rb

@@ -17,6 +17,13 @@ module Lint
       # always return +{}+, and the tests would pass. It is up to you to ensure
       # that the values are semantically meaningful.
       module Tests
+        extend ActiveSupport::Concern
+        included do
+          include SerializationTests
+          include CacheTests
+        end
+      end
+      module SerializationTests
         # Passes if the object responds to <tt>serializable_hash</tt> and if it takes
         # zero or one arguments.
         # Fails otherwise.
@@ -72,6 +79,27 @@ def test_to_json
           resource.to_json(nil)
         end
 
+        def test_active_model_errors
+          assert_respond_to resource, :errors
+        end
+
+        def test_active_model_errors_human_attribute_name
+          assert_respond_to resource.class, :human_attribute_name
+          assert_equal(-2, resource.class.method(:human_attribute_name).arity)
+        end
+
+        def test_active_model_errors_lookup_ancestors
+          assert_respond_to resource.class, :lookup_ancestors
+          assert_equal 0, resource.class.method(:lookup_ancestors).arity
+        end
+
+        private
+
+        def resource
+          @resource or fail "'@resource' must be set as the linted object"
+        end
+      end
+      module CacheTests
         # Passes if the object responds to <tt>cache_key</tt>
         # Fails otherwise.
         #
@@ -121,20 +149,6 @@ def test_model_name
           assert_instance_of resource_class.model_name, ActiveModel::Name
         end
 
-        def test_active_model_errors
-          assert_respond_to resource, :errors
-        end
-
-        def test_active_model_errors_human_attribute_name
-          assert_respond_to resource.class, :human_attribute_name
-          assert_equal(-2, resource.class.method(:human_attribute_name).arity)
-        end
-
-        def test_active_model_errors_lookup_ancestors
-          assert_respond_to resource.class, :lookup_ancestors
-          assert_equal 0, resource.class.method(:lookup_ancestors).arity
-        end
-
         private
 
         def resource

lib/active_model_serializers.rb

@@ -38,6 +38,14 @@ def self.default_include_directive
     @default_include_directive ||= JSONAPI::IncludeDirective.new(config.default_includes, allow_wildcard: true)
   end
 
+  def self.silence_warnings
+    original_verbose = $VERBOSE
+    $VERBOSE = nil
+    yield
+  ensure
+    $VERBOSE = original_verbose
+  end
+
   require 'active_model/serializer/version'
   require 'active_model/serializer'
   require 'active_model/serializable_resource'

lib/active_model_serializers/model.rb

@@ -1,21 +1,36 @@
 # ActiveModelSerializers::Model is a convenient
 # serializable class to inherit from when making
 # serializable non-activerecord objects.
+#
+# Caching support is by-default mixed in when subclassing.
+# To disable mixing in any caching support,
+# set ActiveModelSerializers::Model.add_caching_support = false
 module ActiveModelSerializers
   class Model
     include ActiveModel::Serializers::JSON
     include ActiveModel::Model
+    extend ActiveSupport::Autoload
+    autoload :Caching
 
+    class_attribute :add_caching_support
+    self.add_caching_support = true
     class_attribute :attribute_names
     self.attribute_names = []
 
     def self.attributes(*names)
-      attr_accessor(*names)
-      self.attribute_names = attribute_names | names.map(&:to_sym)
+      self.attribute_names |= names.map(&:to_sym)
+      # Silence redefinition of methods warnings
+      ActiveModelSerializers.silence_warnings do
+        attr_accessor(*names)
+      end
     end
 
-    attributes :id
-    attr_writer :updated_at
+    def self.inherited(host)
+      if add_caching_support && !host.included_modules.include?(ActiveModelSerializers::Model::Caching)
+        host.include(ActiveModelSerializers::Model::Caching)
+      end
+      super
+    end
 
     attr_reader :errors
 
@@ -24,24 +39,6 @@ def initialize(attributes = {})
       super
     end
 
-    # Defaults to the downcased model name.
-    def id
-      @id ||= self.class.name && self.class.name.downcase
-    end
-
-    # Defaults to the downcased model name and updated_at
-    def cache_key
-      ActiveSupport::Cache.expand_cache_key([
-        self.class.name && self.class.name.downcase,
-        "#{id}-#{updated_at.strftime('%Y%m%d%H%M%S%9N')}"
-      ].compact)
-    end
-
-    # Defaults to the time the serializer file was modified.
-    def updated_at
-      defined?(@updated_at) ? @updated_at : File.mtime(__FILE__)
-    end
-
     def attributes
       attribute_names.each_with_object({}) do |attribute_name, result|
         result[attribute_name] = public_send(attribute_name)

lib/active_model_serializers/model/caching.rb

@@ -0,0 +1,25 @@
+module ActiveModelSerializers
+  class Model
+    module Caching
+      extend ActiveSupport::Concern
+
+      included do
+        attr_writer :updated_at
+        attributes :id
+      end
+
+      # Defaults to the downcased model name and updated_at
+      def cache_key
+        ActiveSupport::Cache.expand_cache_key([
+          self.class.model_name.name.downcase,
+          "#{id}-#{updated_at.strftime('%Y%m%d%H%M%S%9N')}"
+        ].compact)
+      end
+
+      # Defaults to the time the serializer file was modified.
+      def updated_at
+        defined?(@updated_at) ? @updated_at : File.mtime(__FILE__)
+      end
+    end
+  end
+end

test/active_model_serializers/model_test.rb

@@ -1,15 +1,24 @@
 require 'test_helper'
 
 module ActiveModelSerializers
-  class ModelTest < ActiveSupport::TestCase
-    include ActiveModel::Serializer::Lint::Tests
+  class CachingModelTest < ActiveSupport::TestCase
+    include ActiveModel::Serializer::Lint::CacheTests
+    class TestModel < ActiveModelSerializers::Model; end
+
+    setup do
+      @resource = TestModel.new
+    end
+  end
+
+  class BasicModelTest < ActiveSupport::TestCase
+    include ActiveModel::Serializer::Lint::SerializationTests
 
     setup do
       @resource = ActiveModelSerializers::Model.new
     end
 
     def test_initialization_with_string_keys
-      klass = Class.new(ActiveModelSerializers::Model) do
+      klass = subclass_without_caching_support do
         attributes :key
       end
       value = 'value'
@@ -20,32 +29,31 @@ def test_initialization_with_string_keys
     end
 
     def test_attributes_can_be_read_for_serialization
-      klass = Class.new(ActiveModelSerializers::Model) do
+      klass = subclass_without_caching_support do
         attributes :one, :two, :three
       end
       original_attributes = { one: 1, two: 2, three: 3 }
       instance = klass.new(original_attributes)
 
       # Initial value
-      expected_attributes = { id: nil, one: 1, two: 2, three: 3 }.with_indifferent_access
+      expected_attributes = { one: 1, two: 2, three: 3 }.with_indifferent_access
       assert_equal expected_attributes, instance.attributes
       assert_equal 1, instance.one
       assert_equal 1, instance.read_attribute_for_serialization(:one)
 
       # Change via accessor
       instance.one = :not_one
 
-      expected_attributes = { id: nil, one: :not_one, two: 2, three: 3 }.with_indifferent_access
+      expected_attributes = { one: :not_one, two: 2, three: 3 }.with_indifferent_access
       assert_equal expected_attributes, instance.attributes
       assert_equal :not_one, instance.one
       assert_equal :not_one, instance.read_attribute_for_serialization(:one)
     end
 
     def test_id_attribute_can_be_read_for_serialization
-      klass = Class.new(ActiveModelSerializers::Model) do
+      klass = subclass_without_caching_support do
         attributes :id, :one, :two, :three
       end
-      self.class.const_set(:SomeTestModel, klass)
       original_attributes = { id: :ego, one: 1, two: 2, three: 3 }
       instance = klass.new(original_attributes)
 
@@ -62,8 +70,16 @@ def test_id_attribute_can_be_read_for_serialization
       assert_equal expected_attributes, instance.attributes
       assert_equal :superego, instance.id
       assert_equal :superego, instance.read_attribute_for_serialization(:id)
+    end
+
+    def subclass_without_caching_support(&block)
+      original_caching_support = ActiveModelSerializers::Model.add_caching_support
+      ActiveModelSerializers::Model.add_caching_support = false
+      Class.new(ActiveModelSerializers::Model) do
+        instance_exec(&block)
+      end
     ensure
-      self.class.send(:remove_const, :SomeTestModel)
+      ActiveModelSerializers::Model.add_caching_support = original_caching_support
     end
   end
 end

test/fixtures/poro.rb

@@ -3,6 +3,11 @@
 class Model < ActiveModelSerializers::Model
   FILE_DIGEST = Digest::MD5.hexdigest(File.open(__FILE__).read)
 
+  # Defaults to the downcased model name.
+  def id
+    @id ||= self.class.model_name.name.downcase
+  end
+
   # At this time, just for organization of intent
   class_attribute :association_names
   self.association_names = []