Move JsonApi object config to JsonApi adapter

Finish #1147

docs/general/configuration_options.md

@@ -9,5 +9,9 @@ The following configuration options can be set on `ActiveModel::Serializer.confi
 ## JSON API
 
 - `jsonapi_resource_type`: Whether the `type` attributes of resources should be singular or plural. Possible values: `:singular, :plural`. Default: `:plural`.
-- `jsonapi_toplevel_member`: Whether to include a [top level JSON API member](http://jsonapi.org/format/#document-jsonapi-object) in the response document. Default: `false`.
-- `jsonapi_version`: The latest version of the spec the API conforms to. Used when `jsonapi_toplevel_member` is `true`. Default: `'1.0'`.
+- `jsonapi_toplevel_member`: Whether to include a [top level JSON API member](http://jsonapi.org/format/#document-jsonapi-object)
+   in the response document. Default: `false`.
+- `jsonapi_version`: The latest version of the spec the API conforms to.
+  Used when `jsonapi_toplevel_member` is `true`. Default: `'1.0'`.
+- `jsonapi_toplevel_meta`: Optional metadata. Not included if empty.
+  Used when `jsonapi_toplevel_member` is `true`. Default: `{}`.

lib/active_model/serializable_resource.rb

@@ -1,8 +1,7 @@
 require 'set'
 module ActiveModel
   class SerializableResource
-    ADAPTER_OPTION_KEYS = Set.new([:include, :fields, :adapter,
-                                   :jsonapi_toplevel_meta])
+    ADAPTER_OPTION_KEYS = Set.new([:include, :fields, :adapter])
 
     # 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/adapter/json_api.rb

@@ -1,16 +1,24 @@
 class ActiveModel::Serializer::Adapter::JsonApi < ActiveModel::Serializer::Adapter
+        # JsonApiObject: namespace for functions that build
+        # JSON API objects
         module JsonApiObject
           # Make JSON API top-level jsonapi member opt-in
           # ref: http://jsonapi.org/format/#document-top-level
           ActiveModel::Serializer.config.jsonapi_toplevel_member = false
+          ActiveModel::Serializer.config.jsonapi_version = '1.0'
+          ActiveModel::Serializer.config.jsonapi_toplevel_meta = {}
           module JsonApi
-            VERSION = "1.0"
             extend self
             def add!(document)
               return document unless ActiveModel::Serializer.config.jsonapi_toplevel_member
-              document.merge!(
-                jsonapi: { version: VERSION },
-              )
+              object = {
+                jsonapi: {
+                  version: ActiveModel::Serializer.config.jsonapi_version,
+                  meta: ActiveModel::Serializer.config.jsonapi_toplevel_meta
+                }
+              }
+              object[:jsonapi].reject! {|_,v| v.blank? }
+              document.merge!(object)
             end
           end
         end
@@ -33,20 +41,11 @@ def initialize(serializer, options = {})
 
         def serializable_hash(options = nil)
           options ||= {}
-          hash =
-            if serializer.respond_to?(:each)
-              serializable_hash_for_collection(serializer, options)
-            else
-              serializable_hash_for_single_resource(serializer, options)
-            end
-
-          if ActiveModel::Serializer.config.jsonapi_toplevel_member
-            hash[:jsonapi] = {}
-            hash[:jsonapi][:version] = ActiveModel::Serializer.config.jsonapi_version
-            hash[:jsonapi][:meta] = @options[:jsonapi_toplevel_meta] if @options[:jsonapi_toplevel_meta]
+          if serializer.respond_to?(:each)
+            serializable_hash_for_collection(serializer, options)
+          else
+            serializable_hash_for_single_resource(serializer, options)
           end
-
-          hash
         end
 
         def fragment_cache(cached_hash, non_cached_hash)
@@ -141,8 +140,8 @@ def relationship_value_for(serializer, options = {})
         end
 
         def relationships_for(serializer)
-          Hash[serializer.associations.map { |association| 
-            [association.key, { data: relationship_value_for(association.serializer, association.options) }] 
+          Hash[serializer.associations.map { |association|
+            [association.key, { data: relationship_value_for(association.serializer, association.options) }]
           }]
         end
 

test/adapter/json_api/toplevel_jsonapi_test.rb

@@ -27,58 +27,56 @@ def setup
             @author.posts = []
           end
 
-          def with_config(option, value)
-            old_value = ActiveModel::Serializer.config[option]
-            ActiveModel::Serializer.config[option] = value
-            yield
-          ensure
-            ActiveModel::Serializer.config[option] = old_value
+          def test_toplevel_jsonapi_defaults_to_false
+            assert_equal config.fetch(:jsonapi_toplevel_member), false
           end
 
           def test_disable_toplevel_jsonapi
-            with_adapter :json_api do
-              with_config(:jsonapi_toplevel_member, false) do
-                hash = ActiveModel::SerializableResource.new(@post).serializable_hash
-                assert_nil(hash[:jsonapi])
-              end
+            with_config(jsonapi_toplevel_member: false) do
+              hash = serialize(@post)
+              assert_nil(hash[:jsonapi])
             end
           end
 
           def test_enable_toplevel_jsonapi
-            with_adapter :json_api do
-              with_config(:jsonapi_toplevel_member, true) do
-                hash = ActiveModel::SerializableResource.new(@post).serializable_hash
-                refute_nil(hash[:jsonapi])
-              end
+            with_config(jsonapi_toplevel_member: true) do
+              hash = serialize(@post)
+              refute_nil(hash[:jsonapi])
             end
           end
 
           def test_default_toplevel_jsonapi_version
-            with_adapter :json_api do
-              with_config(:jsonapi_toplevel_member, true) do
-                hash = ActiveModel::SerializableResource.new(@post).serializable_hash
-                assert_equal('1.0', hash[:jsonapi][:version])
-              end
+            with_config(jsonapi_toplevel_member: true) do
+              hash = serialize(@post)
+              assert_equal('1.0', hash[:jsonapi][:version])
             end
           end
 
           def test_toplevel_jsonapi_no_meta
-            with_adapter :json_api do
-              with_config(:jsonapi_toplevel_member, true) do
-                hash = ActiveModel::SerializableResource.new(@post).serializable_hash
-                assert_nil(hash[:jsonapi][:meta])
-              end
+            with_config(jsonapi_toplevel_member: true) do
+              hash = serialize(@post)
+              assert_nil(hash[:jsonapi][:meta])
             end
           end
 
           def test_toplevel_jsonapi_meta
-            with_adapter :json_api do
-              with_config(:jsonapi_toplevel_member, true) do
-                hash = ActiveModel::SerializableResource.new(@post, jsonapi_toplevel_meta: 'custom').serializable_hash
-                assert_equal('custom', hash[:jsonapi][:meta])
-              end
+            new_config = {
+              jsonapi_toplevel_member: true,
+              jsonapi_toplevel_meta: {
+                'copyright': 'Copyright 2015 Example Corp.'
+              }
+            }
+            with_config(new_config) do
+              hash = serialize(@post)
+              assert_equal(new_config[:jsonapi_toplevel_meta], hash.fetch(:jsonapi).fetch(:meta))
             end
           end
+
+          private
+
+          def serialize(resource, options = {})
+            serializable(resource, { adapter: :json_api}.merge!(options)).serializable_hash
+          end
         end
       end
     end

test/support/serialization_testing.rb

@@ -3,11 +3,30 @@ def before_setup
     ActionController::Base.cache_store.clear
   end
 
+  private
+
   def with_adapter(adapter)
     old_adapter = ActiveModel::Serializer.config.adapter
     ActiveModel::Serializer.config.adapter = adapter
     yield
   ensure
     ActiveModel::Serializer.config.adapter = old_adapter
   end
+
+  def config
+    ActiveModel::Serializer.config
+  end
+
+  def with_config(hash)
+    old_config = config.dup
+    ActiveModel::Serializer.config.update(hash)
+    yield
+  ensure
+    ActiveModel::Serializer.config.replace(old_config)
+  end
+
+  def serializable(resource, options = {})
+    ActiveModel::SerializableResource.new(resource, options)
+  end
+
 end