Make test attributes explicit

- Organize test poros with associations and by serializer
- Freeze derived attributes/associations against mutation
- Cleanup PORO fixtures

Author: bf4

lib/active_model_serializers.rb

@@ -38,6 +38,14 @@ def self.default_include_directive
     @default_include_directive ||= JSONAPI::IncludeDirective.new(config.default_includes, allow_wildcard: true)
   end
 
+  def self.silence_warnings
+    original_verbose = $VERBOSE
+    $VERBOSE = nil
+    yield
+  ensure
+    $VERBOSE = original_verbose
+  end
+
   require 'active_model/serializer/version'
   require 'active_model/serializer'
   require 'active_model/serializable_resource'

lib/active_model_serializers/model.rb

@@ -3,42 +3,58 @@
 # serializable non-activerecord objects.
 module ActiveModelSerializers
   class Model
-    include ActiveModel::Model
     include ActiveModel::Serializers::JSON
+    include ActiveModel::Model
+
+    class_attribute :attribute_names
+    # Initialize +attribute_names+ for all subclasses.  The array is usually
+    # mutated in the +attributes+ method, but can be set directly, as well.
+    self.attribute_names = []
 
     def self.attributes(*names)
-      attr_accessor(*names)
+      self.attribute_names |= names.map(&:to_sym)
+      # Silence redefinition of methods warnings
+      ActiveModelSerializers.silence_warnings do
+        attr_accessor(*names)
+      end
     end
 
-    attr_reader :attributes, :errors
+    attr_reader :errors
+    # NOTE that +updated_at+ isn't included in +attribute_names+,
+    # which means it won't show up in +attributes+ unless a subclass has
+    # either <tt>attributes :updated_at</tt> which will redefine the methods
+    # or <tt>attribute_names << :updated_at</tt>.
+    attr_writer :updated_at
+    # NOTE that +id+ will always be in +attributes+.
+    attributes :id
 
     def initialize(attributes = {})
-      @attributes = attributes && attributes.symbolize_keys
       @errors = ActiveModel::Errors.new(self)
       super
     end
 
-    # Defaults to the downcased model name.
-    def id
-      attributes.fetch(:id) { self.class.name.downcase }
+    # The the fields in +attribute_names+ determines the returned hash.
+    # +attributes+ are returned frozen to prevent any expectations that mutation affects
+    # the actual values in the model.
+    def attributes
+      attribute_names.each_with_object({}) do |attribute_name, result|
+        result[attribute_name] = public_send(attribute_name).freeze
+      end.with_indifferent_access.freeze
     end
 
-    # Defaults to the downcased model name and updated_at
+    # To customize model behavior, this method must be redefined. However,
+    # there are other ways of setting the +cache_key+ a serializer uses.
     def cache_key
-      attributes.fetch(:cache_key) { "#{self.class.name.downcase}/#{id}-#{updated_at.strftime('%Y%m%d%H%M%S%9N')}" }
+      ActiveSupport::Cache.expand_cache_key([
+        self.class.model_name.name.downcase,
+        "#{id}-#{updated_at.strftime('%Y%m%d%H%M%S%9N')}"
+      ].compact)
     end
 
-    # Defaults to the time the serializer file was modified.
+    # When no set, defaults to the time the file was modified.
+    # See NOTE by attr_writer :updated_at
     def updated_at
-      attributes.fetch(:updated_at) { File.mtime(__FILE__) }
-    end
-
-    def read_attribute_for_serialization(key)
-      if key == :id || key == 'id'
-        attributes.fetch(key) { id }
-      else
-        attributes[key]
-      end
+      defined?(@updated_at) ? @updated_at : File.mtime(__FILE__)
     end
 
     # The following methods are needed to be minimally implemented for ActiveModel::Errors

test/action_controller/adapter_selector_test.rb

@@ -15,7 +15,7 @@ def render_using_adapter_override
         end
 
         def render_skipping_adapter
-          @profile = Profile.new(name: 'Name 1', description: 'Description 1', comments: 'Comments 1')
+          @profile = Profile.new(id: 'render_skipping_adapter_id', name: 'Name 1', description: 'Description 1', comments: 'Comments 1')
           render json: @profile, adapter: false
         end
       end
@@ -46,7 +46,7 @@ def test_render_using_adapter_override
 
       def test_render_skipping_adapter
         get :render_skipping_adapter
-        assert_equal '{"name":"Name 1","description":"Description 1","comments":"Comments 1"}', response.body
+        assert_equal '{"id":"render_skipping_adapter_id","name":"Name 1","description":"Description 1"}', response.body
       end
     end
   end

test/action_controller/json_api/fields_test.rb

@@ -5,7 +5,16 @@ module Serialization
     class JsonApi
       class FieldsTest < ActionController::TestCase
         class FieldsTestController < ActionController::Base
-          class PostSerializer < ActiveModel::Serializer
+          class AuthorWithName < Author
+            attributes :first_name, :last_name
+          end
+          class AuthorWithNameSerializer < AuthorSerializer
+            type 'authors'
+          end
+          class PostWithPublishAt < Post
+            attributes :publish_at
+          end
+          class PostWithPublishAtSerializer < ActiveModel::Serializer
             type 'posts'
             attributes :title, :body, :publish_at
             belongs_to :author
@@ -14,19 +23,19 @@ class PostSerializer < ActiveModel::Serializer
 
           def setup_post
             ActionController::Base.cache_store.clear
-            @author = Author.new(id: 1, first_name: 'Bob', last_name: 'Jones')
+            @author = AuthorWithName.new(id: 1, first_name: 'Bob', last_name: 'Jones')
             @comment1 = Comment.new(id: 7, body: 'cool', author: @author)
             @comment2 = Comment.new(id: 12, body: 'awesome', author: @author)
-            @post = Post.new(id: 1337, title: 'Title 1', body: 'Body 1',
-                             author: @author, comments: [@comment1, @comment2],
-                             publish_at: '2020-03-16T03:55:25.291Z')
+            @post = PostWithPublishAt.new(id: 1337, title: 'Title 1', body: 'Body 1',
+                                          author: @author, comments: [@comment1, @comment2],
+                                          publish_at: '2020-03-16T03:55:25.291Z')
             @comment1.post = @post
             @comment2.post = @post
           end
 
           def render_fields_works_on_relationships
             setup_post
-            render json: @post, serializer: PostSerializer, adapter: :json_api, fields: { posts: [:author] }
+            render json: @post, serializer: PostWithPublishAtSerializer, adapter: :json_api, fields: { posts: [:author] }
           end
         end
 

test/action_controller/json_api/transform_test.rb

@@ -5,9 +5,17 @@ module Serialization
     class JsonApi
       class KeyTransformTest < ActionController::TestCase
         class KeyTransformTestController < ActionController::Base
-          class Post < ::Model; end
-          class Author < ::Model; end
-          class TopComment < ::Model; end
+          class Post < ::Model
+            attributes :title, :body, :publish_at
+            associations :author, :top_comments
+          end
+          class Author < ::Model
+            attributes :first_name, :last_name
+          end
+          class TopComment < ::Model
+            attributes :body
+            associations :author, :post
+          end
           class PostSerializer < ActiveModel::Serializer
             type 'posts'
             attributes :title, :body, :publish_at

test/action_controller/namespace_lookup_test.rb

@@ -3,10 +3,16 @@
 module ActionController
   module Serialization
     class NamespaceLookupTest < ActionController::TestCase
-      class Book < ::Model; end
-      class Page < ::Model; end
-      class Chapter < ::Model; end
-      class Writer < ::Model; end
+      class Book < ::Model
+        attributes :title, :body
+        associations :writer, :chapters
+      end
+      class Chapter < ::Model
+        attributes :title
+      end
+      class Writer < ::Model
+        attributes :name
+      end
 
       module Api
         module V2
@@ -93,7 +99,7 @@ def explicit_namespace_as_symbol
             end
 
             def invalid_namespace
-              book = Book.new(title: 'New Post', body: 'Body')
+              book = Book.new(id: 'invalid_namespace_book_id', title: 'New Post', body: 'Body')
 
               render json: book, namespace: :api_v2
             end
@@ -205,7 +211,7 @@ def namespace_set_by_request_headers
 
         assert_serializer ActiveModel::Serializer::Null
 
-        expected = { 'title' => 'New Post', 'body' => 'Body' }
+        expected = { 'id' => 'invalid_namespace_book_id', 'title' => 'New Post', 'body' => 'Body' }
         actual = JSON.parse(@response.body)
 
         assert_equal expected, actual

test/action_controller/serialization_test.rb

@@ -135,7 +135,7 @@ def render_fragment_changed_object_with_relationship
           like = Like.new(id: 1, likeable: comment, time: 3.days.ago)
 
           generate_cached_serializer(like)
-          like.likable = comment2
+          like.likeable = comment2
           like.time = Time.zone.now.to_s
 
           render json: like

test/adapter/json_api/fields_test.rb

@@ -4,9 +4,17 @@ module ActiveModelSerializers
   module Adapter
     class JsonApi
       class FieldsTest < ActiveSupport::TestCase
-        class Post < ::Model; end
-        class Author < ::Model; end
-        class Comment < ::Model; end
+        class Post < ::Model
+          attributes :title, :body
+          associations :author, :comments
+        end
+        class Author < ::Model
+          attributes :name, :birthday
+        end
+        class Comment < ::Model
+          attributes :body
+          associations :author, :post
+        end
 
         class PostSerializer < ActiveModel::Serializer
           type 'posts'

test/adapter/json_api/include_data_if_sideloaded_test.rb

@@ -5,7 +5,9 @@ class Serializer
     module Adapter
       class JsonApi
         class IncludeParamTest < ActiveSupport::TestCase
-          IncludeParamAuthor = Class.new(::Model)
+          IncludeParamAuthor = Class.new(::Model) do
+            associations :tags, :posts
+          end
 
           class CustomCommentLoader
             def all

test/adapter/json_api/linked_test.rb

@@ -1,6 +1,6 @@
 require 'test_helper'
 
-class NestedPost < ::Model; end
+class NestedPost < ::Model; associations :nested_posts end
 class NestedPostSerializer < ActiveModel::Serializer
   has_many :nested_posts
 end
@@ -301,8 +301,8 @@ def test_nil_link_with_specified_serializer
       end
 
       class NoDuplicatesTest < ActiveSupport::TestCase
-        class Post < ::Model; end
-        class Author < ::Model; end
+        class Post < ::Model; associations :author end
+        class Author < ::Model; associations :posts, :roles, :bio end
 
         class PostSerializer < ActiveModel::Serializer
           type 'posts'