Improve readability of relationships test (#1904)

* Really fix intermittent relationship test failures

* Unify the two JSON API relationship test files

I accidentally introduced the duplication when
merging
https://github.com/rails-api/active_model_serializers/pull/1543#issuecomment-193118782
and they've evolved separately since then.

They both have some value and need to be combined.

* Resolve duplicate tests from diverged tests files

* No longer test Association/Relationship interface directly

test/adapter/json_api/relationship_test.rb

@@ -4,13 +4,6 @@ module ActiveModelSerializers
   module Adapter
     class JsonApi
       class RelationshipTest < ActiveSupport::TestCase
-        setup do
-          @blog = Blog.new(id: 1)
-          @author = Author.new(id: 1, name: 'Steve K.', blog: @blog)
-          @serializer = BlogSerializer.new(@blog)
-          ActionController::Base.cache_store.clear
-        end
-
         def test_relationship_with_data
           expected = {
             data: {
@@ -18,26 +11,29 @@ module ActiveModelSerializers
               type: 'blogs'
             }
           }
-          test_relationship(expected, options: { include_data: true })
+
+          model_attributes = { blog: Blog.new(id: 1) }
+          relationship_name = :blog
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_with_nil_model
-          @serializer = BlogSerializer.new(nil)
           expected = { data: nil }
-          test_relationship(expected, options: { include_data: true })
-        end
 
-        def test_relationship_with_nil_serializer
+          model_attributes = { blog: nil }
-          @serializer = nil
+          relationship_name = :blog
-          expected = { data: nil }
+          model = new_model(model_attributes)
-          test_relationship(expected, options: { include_data: true })
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_with_data_array
-          posts = [Post.new(id: 1), Post.new(id: 2)]
-          @serializer = ActiveModel::Serializer::CollectionSerializer.new(posts)
-          @author.posts = posts
-          @author.blog = nil
           expected = {
             data: [
               {
@@ -50,126 +46,350 @@ module ActiveModelSerializers
               }
             ]
           }
-          test_relationship(expected, options: { include_data: true })
+
+          model_attributes = { posts: [Post.new(id: 1), Post.new(id: 2)] }
+          relationship_name = :posts
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_many :posts
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_data_not_included
-          test_relationship({ meta: {} }, options: { include_data: false })
+          expected = { meta: {} }
-        end
 
-        def test_relationship_simple_link
+          model_attributes = { blog: :does_not_matter }
-          links = { self: 'a link' }
+          relationship_name = :blog
-          test_relationship({ links: { self: 'a link' } }, links: links)
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog do
+              include_data false
+            end
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_many_links
-          links = {
-            self: 'a link',
-            related: 'another link'
-          }
           expected = {
             links: {
               self: 'a link',
               related: 'another link'
             }
           }
-          test_relationship(expected, links: links)
-        end
 
-        def test_relationship_block_link
+          model_attributes = { blog: :does_not_matter }
-          links = { self: proc { object.id.to_s } }
+          relationship_name = :blog
-          expected = { links: { self: @blog.id.to_s } }
+          model = new_model(model_attributes)
-          test_relationship(expected, links: links)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog do
+              include_data false
+              link :self, 'a link'
+              link :related, 'another link'
+            end
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_block_link_with_meta
-          links = {
-            self: proc do
-              href object.id.to_s
-              meta(id: object.id)
-            end
-          }
           expected = {
             links: {
               self: {
-                href: @blog.id.to_s,
+                href: '1',
-                meta: { id: @blog.id }
+                meta: { id: 1 }
               }
             }
           }
-          test_relationship(expected, links: links)
+
+          model_attributes = { blog: Blog.new(id: 1) }
+          relationship_name = :blog
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog do
+              include_data false
+              link :self do
+                href object.blog.id.to_s
+                meta(id: object.blog.id)
+              end
+            end
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_simple_meta
-          meta = { id: '1' }
+          expected = { meta: { id: '1' } }
-          expected = { meta: meta }
+
-          test_relationship(expected, meta: meta)
+          model_attributes = { blog: Blog.new(id: 1) }
+          relationship_name = :blog
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog do
+              include_data false
+              meta(id: object.blog.id.to_s)
+            end
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_block_meta
-          meta =  proc do
-            { id: object.id }
-          end
           expected = {
             meta: {
-              id: @blog.id
+              id: 1
             }
           }
-          test_relationship(expected, meta: meta)
+
+          model_attributes = { blog: Blog.new(id: 1) }
+          relationship_name = :blog
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :blog do
+              include_data false
+              meta(id: object.blog.id)
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_simple_link
+          expected = {
+            data: {
+              id: '1337',
+              type: 'bios'
+            },
+            links: {
+              self: '//example.com/link_author/relationships/bio'
+            }
+          }
+
+          model_attributes = { bio: Bio.new(id: 1337) }
+          relationship_name = :bio
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :bio do
+              link :self, '//example.com/link_author/relationships/bio'
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_block_link
+          expected = {
+            data: { id: '1337', type: 'profiles' },
+            links: { related: '//example.com/profiles/1337' }
+          }
+
+          model_attributes = { profile: Profile.new(id: 1337) }
+          relationship_name = :profile
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :profile do
+              id = object.profile.id
+              link :related do
+                "//example.com/profiles/#{id}" if id != 123
+              end
+            end
+          end
+          assert_equal(expected, actual)
         end
 
         def test_relationship_with_everything
-          links = {
-            self: 'a link',
-            related: proc do
-              href object.id.to_s
-              meta object.id
-            end
-
-          }
-          meta = proc do
-            { id: object.id }
-          end
           expected = {
-            data: {
+            data: [{ id: '1337', type: 'likes' }],
-              id: '1',
-              type: 'blogs'
-            },
             links: {
-              self: 'a link',
               related: {
-                href: '1', meta: 1
+                href: '//example.com/likes/1337',
+                meta: { ids: '1337' }
               }
             },
-            meta: {
+            meta: { liked: true }
-              id: @blog.id
+          }
+
+          model_attributes = { likes: [Like.new(id: 1337)] }
+          relationship_name = :likes
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_many :likes do
+              link :related do
+                ids = object.likes.map(&:id).join(',')
+                href "//example.com/likes/#{ids}"
+                meta ids: ids
+              end
+              meta liked: object.likes.any?
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_nil_link
+          expected = {
+            data: { id: '123', type: 'profiles' }
+          }
+
+          model_attributes = { profile: Profile.new(id: 123) }
+          relationship_name = :profile
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_one :profile do
+              id = object.profile.id
+              link :related do
+                "//example.com/profiles/#{id}" if id != 123
+              end
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_block_link_href
+          expected = {
+            data: [{ id: '1337', type: 'locations' }],
+            links: {
+              related: { href: '//example.com/locations/1337' }
             }
           }
-          test_relationship(expected, meta: meta, options: { include_data: true }, links: links)
+
+          model_attributes = { locations: [Location.new(id: 1337)] }
+          relationship_name = :locations
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_many :locations do
+              link :related do
+                ids = object.locations.map(&:id).join(',')
+                href "//example.com/locations/#{ids}"
+              end
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_block_link_href_and_meta
+          expected = {
+            data: [{ id: '1337', type: 'posts' }],
+            links: {
+              related: {
+                href: '//example.com/posts/1337',
+                meta: { ids: '1337' }
+              }
+            }
+          }
+
+          model_attributes =  { posts: [Post.new(id: 1337, comments: [], author: nil)] }
+          relationship_name = :posts
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_many :posts do
+              link :related do
+                ids = object.posts.map(&:id).join(',')
+                href "//example.com/posts/#{ids}"
+                meta ids: ids
+              end
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_block_link_meta
+          expected = {
+            data: [{ id: '1337', type: 'comments' }],
+            links: {
+              self: {
+                meta: { ids: [1] }
+              }
+            }
+          }
+
+          model_attributes = { comments: [Comment.new(id: 1337)] }
+          relationship_name = :comments
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_many :comments do
+              link :self do
+                meta ids: [1]
+              end
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_meta
+          expected = {
+            data: [{ id: 'from-serializer-method', type: 'roles' }],
+            meta: { count: 1 }
+          }
+
+          model_attributes = { roles: [Role.new(id: 'from-record')] }
+          relationship_name = :roles
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            has_many :roles do |serializer|
+              meta count: object.roles.count
+              serializer.cached_roles
+            end
+            def cached_roles
+              [
+                Role.new(id: 'from-serializer-method')
+              ]
+            end
+          end
+          assert_equal(expected, actual)
+        end
+
+        def test_relationship_not_including_data
+          expected = {
+            links: { self: '//example.com/link_author/relationships/blog' }
+          }
+
+          model_attributes = { blog: Object }
+          relationship_name = :blog
+          model = new_model(model_attributes)
+          model.define_singleton_method(:read_attribute_for_serialization) do |attr|
+            fail 'should not be called' if attr == :blog
+            super(attr)
+          end
+          assert_nothing_raised do
+            actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+              has_one :blog do
+                link :self, '//example.com/link_author/relationships/blog'
+                include_data false
+              end
+            end
+            assert_equal(expected, actual)
+          end
+        end
+
+        def test_relationship_including_data_explicit
+          expected = {
+            data: { id: '1337', type: 'authors' },
+            meta: { name: 'Dan Brown' }
+          }
+
+          model_attributes = { reviewer: Author.new(id: 1337) }
+          relationship_name = :reviewer
+          model = new_model(model_attributes)
+          actual = build_serializer_and_serialize_relationship(model, relationship_name) do
+            belongs_to :reviewer do
+              meta name: 'Dan Brown'
+              include_data true
+            end
+          end
+          assert_equal(expected, actual)
         end
 
         private
 
-        def test_relationship(expected, test_options = {})
+        def build_serializer_and_serialize_relationship(model, relationship_name, &block)
-          parent_serializer = AuthorSerializer.new(@author)
+          serializer_class = Class.new(ActiveModel::Serializer, &block)
+          hash = serializable(model, serializer: serializer_class, adapter: :json_api).serializable_hash
+          hash[:data][:relationships][relationship_name]
+        end
 
-          serializable_resource_options = {} # adapter.instance_options
+        def new_model(model_attributes)
+          Class.new(ActiveModelSerializers::Model) do
+            attr_accessor(*model_attributes.keys)
 
-          options = test_options.delete(:options) || {}
+            def self.name
-          options[:links] = test_options.delete(:links)
+              'TestModel'
-          options[:meta] = test_options.delete(:meta)
+            end
-          association_serializer = @serializer
+          end.new(model_attributes)
-          if association_serializer && association_serializer.object
-            association_name = association_serializer.json_key.to_sym
-            options[:serializer] = association_serializer
-            association = ::ActiveModel::Serializer::Association.new(association_name, options, nil)
-          else
-            options[:serializer] = association
-            association = ::ActiveModel::Serializer::Association.new(:association_name_not_used, options, nil)
-          end
-
-          relationship = Relationship.new(parent_serializer, serializable_resource_options, association)
-          assert_equal(expected, relationship.as_json)
         end
       end
     end

test/adapter/json_api/relationships_test.rb

@@ -1,234 +0,0 @@
-require 'test_helper'
-
-module ActiveModel
-  class Serializer
-    module Adapter
-      class JsonApi
-        class RelationshipTest < ActiveSupport::TestCase
-          class RelationshipAuthor < ::Model; end
-
-          class RelationshipAuthorSerializer < ActiveModel::Serializer
-            has_one :bio do
-              link :self, '//example.com/link_author/relationships/bio'
-            end
-
-            has_one :profile do
-              id = object.profile.id
-              link :related do
-                "//example.com/profiles/#{id}" if id != 123
-              end
-            end
-
-            has_many :locations do
-              link :related do
-                ids = object.locations.map(&:id).join(',')
-                href "//example.com/locations/#{ids}"
-              end
-            end
-
-            has_many :posts do
-              link :related do
-                ids = object.posts.map(&:id).join(',')
-                href "//example.com/posts/#{ids}"
-                meta ids: ids
-              end
-            end
-
-            has_many :comments do
-              link :self do
-                meta ids: [1]
-              end
-            end
-
-            has_many :roles do |serializer|
-              meta count: object.posts.count
-              serializer.cached_roles
-            end
-
-            has_one :blog do
-              link :self, '//example.com/link_author/relationships/blog'
-              include_data false
-            end
-
-            belongs_to :reviewer do
-              meta name: 'Dan Brown'
-              include_data true
-            end
-
-            has_many :likes do
-              link :related do
-                ids = object.likes.map(&:id).join(',')
-                href "//example.com/likes/#{ids}"
-                meta ids: ids
-              end
-              meta liked: object.likes.any?
-            end
-
-            def cached_roles
-              [
-                Role.new(id: 'from-serializer-method')
-              ]
-            end
-          end
-
-          def setup
-            @post = Post.new(id: 1337, comments: [], author: nil)
-            @bio = Bio.new(id: 1337)
-            @like = Like.new(id: 1337)
-            @role = Role.new(id: 'from-record')
-            @profile = Profile.new(id: 1337)
-            @location = Location.new(id: 1337)
-            @reviewer = Author.new(id: 1337)
-            @comment = Comment.new(id: 1337)
-            @author = RelationshipAuthor.new(
-              id: 1337,
-              posts: [@post],
-              reviewer: @reviewer,
-              bio: @bio,
-              likes: [@like],
-              roles: [@role],
-              locations: [@location],
-              profile: @profile,
-              comments: [@comment]
-            )
-          end
-
-          def test_relationship_simple_link
-            expected = {
-              data: {
-                id: '1337',
-                type: 'bios'
-              },
-              links: {
-                self: '//example.com/link_author/relationships/bio'
-              }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :bio)
-          end
-
-          def test_relationship_block_link
-            expected = {
-              data: { id: '1337', type: 'profiles' },
-              links: { related: '//example.com/profiles/1337' }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :profile)
-          end
-
-          def test_relationship_nil_link
-            expected = {
-              data: { id: '123', type: 'profiles' }
-            }
-
-            author = @author.dup
-            author.profile.id = 123
-            assert_author_relationship_serialized(expected, author, :profile)
-          end
-
-          def test_relationship_block_link_href
-            expected = {
-              data: [{ id: '1337', type: 'locations' }],
-              links: {
-                related: { href: '//example.com/locations/1337' }
-              }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :locations)
-          end
-
-          def test_relationship_block_link_href_and_meta
-            expected = {
-              data: [{ id: '1337', type: 'posts' }],
-              links: {
-                related: {
-                  href: '//example.com/posts/1337',
-                  meta: { ids: '1337' }
-                }
-              }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :posts)
-          end
-
-          def test_relationship_block_link_meta
-            expected = {
-              data: [{ id: '1337', type: 'comments' }],
-              links: {
-                self: {
-                  meta: { ids: [1] }
-                }
-              }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :comments)
-          end
-
-          def test_relationship_meta
-            expected = {
-              data: [{ id: 'from-serializer-method', type: 'roles' }],
-              meta: { count: 1 }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :roles)
-          end
-
-          def test_relationship_not_including_data
-            expected = {
-              links: { self: '//example.com/link_author/relationships/blog' }
-            }
-
-            author = @author.dup
-            author.define_singleton_method(:read_attribute_for_serialization) do |attr|
-              fail 'should not be called' if attr == :blog
-              super(attr)
-            end
-            assert_nothing_raised do
-              assert_author_relationship_serialized(expected, author, :blog)
-            end
-          end
-
-          def test_relationship_including_data_explicit
-            expected = {
-              data: { id: '1337', type: 'authors' },
-              meta: { name: 'Dan Brown' }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :reviewer)
-          end
-
-          def test_relationship_with_everything
-            expected = {
-              data: [{ id: '1337', type: 'likes' }],
-              links: {
-                related: {
-                  href: '//example.com/likes/1337',
-                  meta: { ids: '1337' }
-                }
-              },
-              meta: { liked: true }
-            }
-
-            author = @author.dup
-            assert_author_relationship_serialized(expected, author, :likes)
-          end
-
-          private
-
-          def assert_author_relationship_serialized(expected, author, relationship_name)
-            hash = serializable(author, adapter: :json_api).serializable_hash
-            actual_relationship = hash[:data][:relationships][relationship_name]
-            assert_equal(expected, actual_relationship)
-          end
-        end
-      end
-    end
-  end
-end