begin playing with using JSON API for deserialization

extract key_transfor

chaneg to case_transform gem

fix

tests pass

Gemfile

@@ -7,6 +7,9 @@ eval_gemfile local_gemfile if File.readable?(local_gemfile)
 # Specify your gem's dependencies in active_model_serializers.gemspec
 gemspec
 
+# TODO: remove when @beauby re-publishes this gem
+gem 'jsonapi', github: 'beauby/jsonapi'
+
 version = ENV['RAILS_VERSION'] || '4.2'
 
 if version == 'master'

active_model_serializers.gemspec

@@ -43,6 +43,7 @@ Gem::Specification.new do |spec|
   # 'thread_safe'
 
   spec.add_runtime_dependency 'jsonapi', '~> 0.1.1.beta2'
+  spec.add_runtime_dependency 'case_transform', '>= 0.2'
 
   spec.add_development_dependency 'activerecord', rails_versions
   # arel

lib/active_model_serializers/adapter/base.rb

@@ -1,4 +1,4 @@
-require 'active_model_serializers/key_transform'
+require 'case_transform'
 
 module ActiveModelSerializers
   module Adapter
@@ -31,7 +31,7 @@ def self.transform(options)
       # @param options [Object] serializable resource options
       # @return [Symbol] the default transform for the adapter
       def self.transform_key_casing!(value, options)
-        KeyTransform.send(transform(options), value)
+        CaseTransform.send(transform(options), value)
       end
 
       def self.cache_key

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::Parser::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::Parser::InvalidDocument
+          return {} unless block_given?
+          yield
         end
-        # rubocop:enable Metrics/CyclomaticComplexity
 
         # @api private
         def filter_fields(fields, options)
@@ -205,7 +173,7 @@ def parse_relationships(relationships, options)
         # @api private
         def transform_keys(hash, options)
           transform = options[:key_transform] || :underscore
-          KeyTransform.send(transform, hash)
+          CaseTransform.send(transform, hash)
         end
       end
     end

test/action_controller/json_api/transform_test.rb

@@ -3,8 +3,8 @@
 module ActionController
   module Serialization
     class JsonApi
-      class KeyTransformTest < ActionController::TestCase
-        class KeyTransformTestController < ActionController::Base
+      class CaseTransformTest < ActionController::TestCase
+        class CaseTransformTestController < ActionController::Base
           class Post < ::Model; end
           class Author < ::Model; end
           class TopComment < ::Model; end
@@ -69,7 +69,7 @@ def render_resource_with_transform_with_global_config
           end
         end
 
-        tests KeyTransformTestController
+        tests CaseTransformTestController
 
         def test_render_resource_with_transform
           get :render_resource_with_transform