Singletons: Fix broken reload method

Prior to this commit, singleton resources were unable to invoke `reload`
to re-fetch themselves and load new data.

To resolve that issue, this commit introduces a protected
`Base#find_self` method that can be overridden by the
`Singleton#find_self` version.

Author: seanpdoyle

lib/active_resource/base.rb

@@ -1553,7 +1553,7 @@ def encode(options = {})
     #   my_branch.name # => "Wilson Road"
     def reload
       run_callbacks :reload do
-        self.load(self.class.find(to_param, params: @prefix_options).attributes, false, true)
+        self.load(find_self.attributes, false, true)
       end
     end
 
@@ -1809,6 +1809,10 @@ def find_or_create_resource_for(name)
         end
       end
 
+      def find_self
+        self.class.find(to_param, params: @prefix_options)
+      end
+
       def const_valid?(*const_args)
         self.class.const_defined?(*const_args)
         true

lib/active_resource/singleton.rb

@@ -141,5 +141,9 @@ def create(path = singleton_path)
       def singleton_path(options = nil)
         self.class.singleton_path(options || prefix_options)
       end
+
+      def find_self
+        self.class.find(@prefix_options)
+      end
   end
 end

test/cases/callbacks_test.rb

@@ -164,6 +164,21 @@ def test_reload
     ], developer.history
   end
 
+  def test_reload_singleton
+    weather = Weather.find
+    weather.reload
+    assert_equal [
+      [ :before_reload,               :method ],
+      [ :before_reload,               :proc   ],
+      [ :before_reload,               :object ],
+      [ :before_reload,               :block  ],
+      [ :after_reload,                :method ],
+      [ :after_reload,                :proc   ],
+      [ :after_reload,                :object ],
+      [ :after_reload,                :block  ]
+    ], weather.history
+  end
+
   def test_update
     developer = Developer.find(1)
     developer.save

test/singleton_test.rb

@@ -143,4 +143,18 @@ def test_update
     weather.status = "Rainy"
     weather.save
   end
+
+  def test_reload
+    setup_weather
+
+    # First Create the Weather
+    weather = Weather.create!(status: "Sunny", temperature: 67)
+
+    # Then reload it
+    weather.reload
+
+    request = ActiveResource::HttpMock.requests.last
+    assert_equal :get, request.method
+    assert_equal "/weather.json", request.path
+  end
 end