Fix relationships of included objects (#8)

* Fix parsing of objects that are only in relationships of included

If an object was present only in the relationships of an included object
and not in the root of the data object or the included object it was not
being parsed correctly.

* Make original_keys in prepare_object optional

* Add spec for prepare_object method

* Invoke prepare_class method only when it is needed

lib/json-api-vanilla/parser.rb

@@ -58,17 +58,12 @@ def self.build(hash)
 
     obj_hashes.each do |o_hash|
       klass = prepare_class(o_hash, superclass, container)
-      obj = klass.new
-      obj.type = o_hash['type']
-      obj.id = o_hash['id']
-      if o_hash['attributes']
-        o_hash['attributes'].each do |key, value|
-          set_key(obj, key, value, original_keys)
-        end
-      end
+      obj = prepare_object(o_hash, klass, original_keys)
+
       if o_hash['links']
         links[obj] = o_hash['links']
       end
+
       objects[[obj.type, obj.id]] = obj
     end
 
@@ -82,10 +77,22 @@ def self.build(hash)
             if data.is_a?(Array)
               # One-to-many relationship.
               ref = data.map do |ref_hash|
-                objects[[ref_hash['type'], ref_hash['id']]]
+                _ref = objects[[ref_hash['type'], ref_hash['id']]]
+
+                if _ref.nil?
+                  klass = prepare_class(ref_hash, superclass, container)
+                  _ref = prepare_object(ref_hash, klass)
+                end
+
+                _ref
               end
             else
               ref = objects[[data['type'], data['id']]]
+
+              if ref.nil?
+                klass = prepare_class(data, superclass, container)
+                ref = prepare_object(data, klass)
+              end
             end
           end
 
@@ -130,6 +137,18 @@ def self.prepare_class(hash, superclass, container)
     klass
   end
 
+  def self.prepare_object(hash, klass, original_keys = {})
+    (klass.new).tap do |obj|
+      obj.type = hash['type']
+      obj.id = hash['id']
+      if hash['attributes']
+        hash['attributes'].each do |key, value|
+          set_key(obj, key, value, original_keys)
+        end
+      end
+    end
+  end
+
   def self.generate_object(ruby_name, superclass, container)
     klass = Class.new(superclass)
     container.const_set(ruby_name, klass)

spec/json-api-vanilla/diff_spec.rb

@@ -20,6 +20,14 @@
     expect(doc.links[doc.data]['self']).to eql("http://example.com/articles")
   end
 
+  it "should read objects that are only in relationships of included" do
+    expect(doc.data.first.comments.first.post.id).to eql("42")
+  end
+
+  it "should read objects that are only in relationships of included when it is an array" do
+    expect(doc.data.first.comments.first.tags[0].id).to eql("42")
+  end
+
   it "should find objects by type and id" do
     expect(doc.find('comments', '5').body).to eql("First!")
   end
@@ -114,4 +122,24 @@ class TestClasses
       end
     end
   end
+
+  describe '.prepare_object' do
+    let(:data) do
+      {
+        'type' => 'example',
+        'id' => '1',
+        'attributes' => {
+          'name' => 'example name'
+        }
+      }
+    end
+    let(:klass) { described_class.prepare_class(data, Class.new, Module.new) }
+    subject { described_class.prepare_object(data, klass) }
+
+    it 'creates an object with the attributes mapped' do
+      expect(subject.type).to eql(data['type'])
+      expect(subject.id).to eql(data['id'])
+      expect(subject.name).to eql(data['attributes']['name'])
+    end
+  end
 end

spec/json-api-vanilla/example.json

@@ -56,6 +56,17 @@
     "relationships": {
       "author": {
         "data": { "type": "people", "id": "2" }
+      },
+      "tags": {
+        "data": [
+          { "type": "tag", "id": "42" }
+        ]
+      },
+      "post": {
+        "data": {
+          "type": "post",
+          "id": "42"
+        }
       }
     },
     "links": {