Refactor adapters to implement support for array serialization

test/adapter/json_api/belongs_to_test.rb

@@ -16,7 +16,7 @@ module ActiveModel
           end
 
           def test_includes_post_id
-            assert_equal(42, @adapter.serializable_hash[:links][:post])
+            assert_equal(42, @adapter.serializable_hash[:comments][:links][:post])
           end
 
           def test_includes_linked_post

test/adapter/json_api/collection_test.rb

@@ -0,0 +1,28 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class Adapter
+      class JsonApi
+        class Collection < Minitest::Test
+          def setup
+            @first_post = Post.new(id: 1, title: 'Hello!!', body: 'Hello, world!!')
+            @second_post = Post.new(id: 2, title: 'New Post', body: 'Body')
+            @first_post.comments = []
+            @second_post.comments = []
+
+            @serializer = ArraySerializer.new([@first_post, @second_post])
+            @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
+          end
+
+          def test_include_multiple_posts
+            assert_equal([
+                           {title: "Hello!!", body: "Hello, world!!", id: 1, links: {comments: []}},
+                           {title: "New Post", body: "Body", id: 2, links: {comments: []}}
+                         ], @adapter.serializable_hash[:posts])
+          end
+        end
+      end
+    end
+  end
+end

test/adapter/json_api/has_many_embed_ids.rb

@@ -18,7 +18,7 @@ module ActiveModel
           end
 
           def test_includes_comment_ids
-            assert_equal([1, 2], @adapter.serializable_hash[:links][:posts])
+            assert_equal([1, 2], @adapter.serializable_hash[:authors][:links][:posts])
           end
 
           def test_no_includes_linked_comments

test/adapter/json_api/has_many_test.rb

@@ -18,7 +18,7 @@ module ActiveModel
           end
 
           def test_includes_comment_ids
-            assert_equal([1, 2], @adapter.serializable_hash[:links][:comments])
+            assert_equal([1, 2], @adapter.serializable_hash[:posts][:links][:comments])
           end
 
           def test_includes_linked_comments