fixed the test for has_one without included data

lib/json_api_client/associations/has_one.rb

@@ -16,4 +16,4 @@ def from_result_set(result_set)
       end
     end
   end
-end
+end

lib/json_api_client/included_data.rb

@@ -18,29 +18,26 @@ def initialize(result_set, data)
     end
 
     def data_for(method_name, definition)
+      # this method only returns an array. It's up to the caller to decide if it's going to return
+      # just the first element if it's a has_one relationship. 
       # If data is defined, pull the record from the included data
-      return nil unless data = definition["data"]
-
-      if data.is_a?(Array)
-        # has_many link
-        data.map do |link_def|
-          record_for(link_def)
+      defined_data = definition["data"]
+      return nil unless defined_data
+      [defined_data].flatten.map do |link_def|
+        # should return a resource record of some type for this linked document
+        # even if there's no matching record included.
+        if data[link_def["type"]] 
+          data[link_def["type"]][link_def["id"]]
+        else
+          # if there's no matching record in included then go and get it given the data
+          link_def["type"].underscore.classify.constantize.find(link_def["id"]).first
         end
-      else
-        # has_one link
-        record_for(data)
       end
     end
 
     def has_link?(name)
       data.has_key?(name.to_s)
     end
 
-    private
-
-    # should return a resource record of some type for this linked document
-    def record_for(link_def)
-      data[link_def["type"]][link_def["id"]]
-    end
   end
 end

lib/json_api_client/resource.rb

@@ -448,10 +448,17 @@ def method_missing(method, *args)
       return nil unless relationship_definitions = relationships[method]
 
       # look in included data
-      if relationship_definitions.key?("data")
-        return last_result_set.included.data_for(method, relationship_definitions)
-      end
-
+       if relationship_definitions.key?("data")
+         # included.data_for returns an array, if the association is a has_one, then pick the first, otherise return the whole array
+         if association.is_a?(JsonApiClient::Associations::HasOne::Association)
+          return last_result_set.included.data_for(method, relationship_definitions).try(:first)
+         else
+          return last_result_set.included.data_for(method, relationship_definitions)
+         end
+       end
+
+      # I'm very puzzled by this as we have association = association_for(method) in the first line of this method
+       # is it intened to be 'if association == association_for(method)'
       if association = association_for(method)
         # look for a defined relationship url
         if relationship_definitions["links"] && url = relationship_definitions["links"]["related"]

test/unit/association_test.rb

@@ -33,7 +33,7 @@ class Property < TestResource
 
 class AssociationTest < MiniTest::Test
 
-  def test_load_has_one
+  def test_load_has_one_without_include
     stub_request(:get, "http://example.com/properties/1")
       .to_return(headers: {content_type: "application/vnd.api+json"}, body: {
         data: [
@@ -48,17 +48,20 @@ def test_load_has_one
               }
             }
           }
-        ],
-        included: [
+        ]
+
+      }.to_json)
+    stub_request(:get, "http://example.com/owners/1")
+      .to_return(headers: {content_type: "application/vnd.api+json"}, body: {
+        data: [
           {
             id: 1,
-            type: 'owner',
+            type: "owner",
             attributes: {
-              name: 'Jeff Ching'
+              name: "Jeff Ching"
             }
           }
         ]
-
       }.to_json)
     property = Property.find(1).first
     assert_equal(Owner, property.owner.class)
@@ -96,6 +99,7 @@ def test_load_has_one_with_include
 
              }.to_json)
     property = Property.includes(:owner).find(1).first
+    assert_equal(Owner, property.owner.class)
     assert_equal("Jeff Ching", property.owner.name)
   end