HasOne assocation will now fetch association when not included.

Thanks @JohnSmall for the original [PR #244](JsonApiClient/json_api_client#244)

Author: jsmestad

lib/jsonapi/consumer/included_data.rb

@@ -18,17 +18,20 @@ 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|
+      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"]]
           record_for(link_def)
+        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
 

lib/jsonapi/consumer/resource.rb

@@ -491,7 +491,12 @@ def method_missing(method, *args)
 
       # look in included data
       if relationship_definitions.key?("data")
-        return last_result_set.included.data_for(method, relationship_definitions)
+        # 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?(JSONAPI::Consumer::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
 
       if association = association_for(method)

test/unit/association_test.rb

@@ -125,6 +125,41 @@ def test_load_has_one_with_include
     assert_equal("Jeff Ching", property.owner.name)
   end
 
+  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: [
+          {
+            id: 1,
+            attributes: {
+              address: "123 Main St."
+            },
+            relationships: {
+              owner: {
+                data: {id: 1, type: "owner"}
+              }
+            }
+          }
+        ]
+
+      }.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",
+            attributes: {
+              name: "Jeff Ching"
+            }
+          }
+        ]
+      }.to_json)
+    property = Property.find(1).first
+    assert_equal(Owner, property.owner.class)
+    assert_equal("Jeff Ching", property.owner.name)
+  end
+
   def test_has_one_loads_nil
     stub_request(:get, "http://example.com/properties/1")
       .to_return(headers: {content_type: "application/vnd.api+json"}, body: {