Lead by example: lint PORO model

lib/active_model/serializer/lint.rb

@@ -106,7 +106,7 @@ module ActiveModel::Serializer::Lint
     private
 
     def resource
-      @resource
+      @resource or fail "'@resource' must be set as the linted object"
     end
 
     def assert_instance_of(result, name)

test/fixtures/poro.rb

@@ -13,12 +13,8 @@ class Model
     "#{self.class.name.downcase}/#{self.id}-#{self.updated_at.strftime("%Y%m%d%H%M%S%9N")}"
   end
 
-  def cache_key_with_digest
-    "#{cache_key}/#{FILE_DIGEST}"
-  end
-
-  def updated_at
-    @attributes[:updated_at] ||= DateTime.now.to_time
+  def serializable_hash(options = nil)
+    @attributes
   end
 
   def read_attribute_for_serialization(name)
@@ -33,6 +29,9 @@ class Model
     @attributes[:id] || @attributes['id'] || object_id
   end
 
+  ### Helper methods, not required to be serializable
+  #
+  # Convenience for adding @attributes readers and writers
   def method_missing(meth, *args)
     if meth.to_s =~ /^(.*)=$/
       @attributes[$1.to_sym] = args[0]
@@ -42,6 +41,14 @@ class Model
       super
     end
   end
+
+  def cache_key_with_digest
+    "#{cache_key}/#{FILE_DIGEST}"
+  end
+
+  def updated_at
+    @attributes[:updated_at] ||= DateTime.now.to_time
+  end
 end
 
 class Profile < Model

test/poro_test.rb

@@ -0,0 +1,9 @@
+require 'test_helper'
+
+class PoroTest < Minitest::Test
+  include ActiveModel::Serializer::Lint::Tests
+
+  def setup
+    @resource = Model.new
+  end
+end