begin playing with using JSON API for deserialization

Author: NullVoxPopuli

lib/active_model_serializers/adapter/json_api/deserialization.rb

@@ -1,12 +1,12 @@
+require 'jsonapi'
+
 module ActiveModelSerializers
   module Adapter
     class JsonApi
       # NOTE(Experimental):
       # This is an experimental feature. Both the interface and internals could be subject
       # to changes.
       module Deserialization
-        InvalidDocument = Class.new(ArgumentError)
-
         module_function
 
         # Transform a JSON API document, containing a single data object,
@@ -74,21 +74,21 @@ module Deserialization
         #
         def parse!(document, options = {})
           parse(document, options) do |invalid_payload, reason|
-            fail InvalidDocument, "Invalid payload (#{reason}): #{invalid_payload}"
+            fail JSONAPI::InvalidDocument, "Invalid payload (#{reason}): #{invalid_payload}"
           end
         end
 
         # Same as parse!, but returns an empty hash instead of raising InvalidDocument
         # on invalid payloads.
         def parse(document, options = {})
-          document = document.dup.permit!.to_h if document.is_a?(ActionController::Parameters)
-
-          validate_payload(document) do |invalid_document, reason|
-            yield invalid_document, reason if block_given?
-            return {}
-          end
+          document = JSONAPI.parse(document, options)
+          document = document.to_hash
 
           primary_data = document['data']
+
+          # null data is allowed, as per the JSON API Schema
+          return {} unless primary_data
+
           attributes = primary_data['attributes'] || {}
           attributes['id'] = primary_data['id'] if primary_data['id']
           relationships = primary_data['relationships'] || {}
@@ -101,43 +101,11 @@ def parse(document, options = {})
           hash.merge!(parse_relationships(relationships, options))
 
           hash
-        end
-
-        # Checks whether a payload is compliant with the JSON API spec.
-        #
-        # @api private
-        # rubocop:disable Metrics/CyclomaticComplexity
-        def validate_payload(payload)
-          unless payload.is_a?(Hash)
-            yield payload, 'Expected hash'
-            return
-          end
 
-          primary_data = payload['data']
-          unless primary_data.is_a?(Hash)
-            yield payload, { data: 'Expected hash' }
-            return
-          end
-
-          attributes = primary_data['attributes'] || {}
-          unless attributes.is_a?(Hash)
-            yield payload, { data: { attributes: 'Expected hash or nil' } }
-            return
-          end
-
-          relationships = primary_data['relationships'] || {}
-          unless relationships.is_a?(Hash)
-            yield payload, { data: { relationships: 'Expected hash or nil' } }
-            return
-          end
-
-          relationships.each do |(key, value)|
-            unless value.is_a?(Hash) && value.key?('data')
-              yield payload, { data: { relationships: { key => 'Expected hash with :data key' } } }
-            end
-          end
+        rescue JSONAPI::InvalidDocument
+          return {} unless block_given?
+          yield
         end
-        # rubocop:enable Metrics/CyclomaticComplexity
 
         # @api private
         def filter_fields(fields, options)

test/adapter/json_api/parse_test.rb

@@ -3,7 +3,7 @@ module ActiveModelSerializers
   module Adapter
     class JsonApi
       module Deserialization
-        class ParseTest < Minitest::Test
+        class ParseTest < ActiveSupport::TestCase
           def setup
             @hash = {
               'data' => {
@@ -41,21 +41,11 @@ def setup
 
             @illformed_payloads = [nil,
                                    {},
-                                   {
-                                     'data' => nil
-                                   }, {
-                                     'data' => { 'attributes' => [] }
-                                   }, {
-                                     'data' => { 'relationships' => [] }
-                                   }, {
-                                     'data' => {
-                                       'relationships' => { 'rel' => nil }
-                                     }
-                                   }, {
-                                     'data' => {
-                                       'relationships' => { 'rel' => {} }
-                                     }
-                                   }]
+                                   { 'data' => { 'attributes' => [] } },
+                                   { 'data' => { 'relationships' => [] } },
+                                   { 'data' => { 'relationships' => { 'rel' => nil } } },
+                                   { 'data' => { 'relationships' => { 'rel' => {} } } }
+                                 ]
           end
 
           def test_hash
@@ -76,9 +66,14 @@ def test_illformed_payloads_safe
             end
           end
 
+          test 'null data is allow per the JSON API Schema' do
+            parsed_hash = ActiveModelSerializers::Adapter::JsonApi::Deserialization.parse!('data' => nil)
+            assert_equal({}, parsed_hash)
+          end
+
           def test_illformed_payloads_unsafe
             @illformed_payloads.each do |p|
-              assert_raises(InvalidDocument) do
+              assert_raises(JSONAPI::InvalidDocument) do
                 ActiveModelSerializers::Adapter::JsonApi::Deserialization.parse!(p)
               end
             end