Move meta/meta_key handling inside adapter.

Author: beauby

CHANGELOG.md

@@ -24,6 +24,7 @@ Fixes:
 - [#1214](https://github.com/rails-api/active_model_serializers/pull/1214) retrieve the key from the reflection options when building associations (@NullVoxPopuli, @hut8)
 
 Misc:
+- [#1233](https://github.com/rails-api/active_model_serializers/pull/1233) Top-level meta and meta_key options no longer handled at serializer level (@beauby)
 - [#1232](https://github.com/rails-api/active_model_serializers/pull/1232) fields option no longer handled at serializer level (@beauby)
 - [#1178](https://github.com/rails-api/active_model_serializers/pull/1178) env CAPTURE_STDERR=false lets devs see hard failures (@bf4)
 - [#1177](https://github.com/rails-api/active_model_serializers/pull/1177) Remove Adapter autoloads in favor of require (@bf4)

lib/active_model/serializable_resource.rb

@@ -1,7 +1,7 @@
 require 'set'
 module ActiveModel
   class SerializableResource
-    ADAPTER_OPTION_KEYS = Set.new([:include, :fields, :adapter])
+    ADAPTER_OPTION_KEYS = Set.new([:include, :fields, :adapter, :meta, :meta_key])
 
     # Primary interface to composing a resource with a serializer and adapter.
     # @return the serializable_resource, ready for #as_json/#to_json/#serializable_hash.

lib/active_model/serializer.rb

@@ -121,15 +121,13 @@ def self.get_serializer_for(klass)
       end
     end
 
-    attr_accessor :object, :root, :meta, :meta_key, :scope
+    attr_accessor :object, :root, :scope
     class_attribute :_type, instance_writer: false
 
     def initialize(object, options = {})
       self.object = object
       self.instance_options = options
       self.root = instance_options[:root]
-      self.meta = instance_options[:meta]
-      self.meta_key = instance_options[:meta_key]
       self.scope = instance_options[:scope]
 
       scope_name = instance_options[:scope_name]

lib/active_model/serializer/adapter/base.rb

@@ -37,11 +37,11 @@ def cache_check(serializer)
         private
 
         def meta
-          serializer.meta if serializer.respond_to?(:meta)
+          instance_options.fetch(:meta, nil)
         end
 
         def meta_key
-          serializer.meta_key || 'meta'.freeze
+          instance_options.fetch(:meta_key, 'meta'.freeze)
         end
 
         def root

lib/active_model/serializer/array_serializer.rb

@@ -5,7 +5,7 @@ class ArraySerializer
       include Enumerable
       delegate :each, to: :@serializers
 
-      attr_reader :object, :root, :meta, :meta_key
+      attr_reader :object, :root
 
       def initialize(resources, options = {})
         @root = options[:root]
@@ -21,8 +21,6 @@ def initialize(resources, options = {})
             serializer_class.new(resource, options.except(:serializer))
           end
         end
-        @meta     = options[:meta]
-        @meta_key = options[:meta_key]
       end
 
       def json_key

test/array_serializer_test.rb

@@ -41,14 +41,6 @@ def test_serializer_option_not_passed_to_each_serializer
         refute serializers.first.custom_options.key?(:serializer)
       end
 
-      def test_meta_and_meta_key_attr_readers
-        meta_content = { meta: 'the meta', meta_key: 'the meta key' }
-        @serializer = ArraySerializer.new([@comment, @post], meta_content)
-
-        assert_equal @serializer.meta, 'the meta'
-        assert_equal @serializer.meta_key, 'the meta key'
-      end
-
       def test_root_default
         @serializer = ArraySerializer.new([@comment, @post])
         assert_equal @serializer.root, nil

test/serializers/meta_test.rb

@@ -4,16 +4,18 @@ module ActiveModel
   class Serializer
     class MetaTest < Minitest::Test
       def setup
-        ActionController::Base.cache_store.clear
         @blog = Blog.new(id: 1,
                          name: 'AMS Hints',
                          writer: Author.new(id: 2, name: 'Steve'),
                          articles: [Post.new(id: 3, title: 'AMS')])
       end
 
       def test_meta_is_present_with_root
-        serializer = AlternateBlogSerializer.new(@blog, meta: { total: 10 })
-        adapter = ActiveModel::Serializer::Adapter::Json.new(serializer)
+        actual = ActiveModel::SerializableResource.new(
+          @blog,
+          adapter: :json,
+          serializer: AlternateBlogSerializer,
+          meta: { total: 10 }).as_json
         expected = {
           blog: {
             id: 1,
@@ -23,22 +25,29 @@ def test_meta_is_present_with_root
             total: 10
           }
         }
-        assert_equal expected, adapter.as_json
+        assert_equal(expected, actual)
       end
 
       def test_meta_is_not_included_when_root_is_missing
-        # load_adapter uses Attributes Adapter
-        adapter = load_adapter(meta: { total: 10 })
+        actual = ActiveModel::SerializableResource.new(
+          @blog,
+          adapter: :attributes,
+          serializer: AlternateBlogSerializer,
+          meta: { total: 10 }).as_json
         expected = {
           id: 1,
           title: 'AMS Hints'
         }
-        assert_equal expected, adapter.as_json
+        assert_equal(expected, actual)
       end
 
       def test_meta_key_is_used
-        serializer = AlternateBlogSerializer.new(@blog, meta: { total: 10 }, meta_key: 'haha_meta')
-        adapter = ActiveModel::Serializer::Adapter::Json.new(serializer)
+        actual = ActiveModel::SerializableResource.new(
+          @blog,
+          adapter: :json,
+          serializer: AlternateBlogSerializer,
+          meta: { total: 10 },
+          meta_key: 'haha_meta').as_json
         expected = {
           blog: {
             id: 1,
@@ -48,12 +57,16 @@ def test_meta_key_is_used
             total: 10
           }
         }
-        assert_equal expected, adapter.as_json
+        assert_equal(expected, actual)
       end
 
       def test_meta_key_is_used_with_json_api
-        serializer = AlternateBlogSerializer.new(@blog, meta: { total: 10 }, meta_key: 'haha_meta')
-        adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+        actual = ActiveModel::SerializableResource.new(
+          @blog,
+          adapter: :json_api,
+          serializer: AlternateBlogSerializer,
+          meta: { total: 10 },
+          meta_key: 'haha_meta').as_json
         expected = {
           data: {
             id: '1',
@@ -62,13 +75,14 @@ def test_meta_key_is_used_with_json_api
           },
           'haha_meta' => { total: 10 }
         }
-        assert_equal expected, adapter.as_json
+        assert_equal(expected, actual)
       end
 
       def test_meta_is_not_present_on_arrays_without_root
-        serializer = ArraySerializer.new([@blog], meta: { total: 10 })
-        # Attributes doesn't have support to root
-        adapter = ActiveModel::Serializer::Adapter::Attributes.new(serializer)
+        actual = ActiveModel::SerializableResource.new(
+          [@blog],
+          adapter: :attributes,
+          meta: { total: 10 }).as_json
         expected = [{
           id: 1,
           name: 'AMS Hints',
@@ -82,13 +96,15 @@ def test_meta_is_not_present_on_arrays_without_root
             body: nil
           }]
         }]
-        assert_equal expected, adapter.as_json
+        assert_equal(expected, actual)
       end
 
       def test_meta_is_present_on_arrays_with_root
-        serializer = ArraySerializer.new([@blog], meta: { total: 10 }, meta_key: 'haha_meta')
-        # JSON adapter adds root by default
-        adapter = ActiveModel::Serializer::Adapter::Json.new(serializer)
+        actual = ActiveModel::SerializableResource.new(
+          [@blog],
+          adapter: :json,
+          meta: { total: 10 },
+          meta_key: 'haha_meta').as_json
         expected = {
           blogs: [{
             id: 1,
@@ -107,14 +123,7 @@ def test_meta_is_present_on_arrays_with_root
             total: 10
           }
         }
-        assert_equal expected, adapter.as_json
-      end
-
-      private
-
-      def load_adapter(options)
-        options = options.merge(adapter: :attributes, serializer: AlternateBlogSerializer)
-        ActiveModel::SerializableResource.new(@blog, options)
+        assert_equal(expected, actual)
       end
     end
   end