From 91235ba7bc7397df1893698c099e3bad54bad78a Mon Sep 17 00:00:00 2001
From: Lucas Hosseini <lucas.hosseini@gmail.com>
Date: Mon, 24 Aug 2015 22:46:11 +0200
Subject: [PATCH] Add configuration option to set resource type to
 singular/plural with jsonapi.

---
 lib/active_model/serializer.rb                |  6 +-
 lib/active_model/serializer/configuration.rb  |  1 +
 .../json_api/resource_type_config_test.rb     | 59 +++++++++++++++++++
 3 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 test/adapter/json_api/resource_type_config_test.rb

diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index 738743007..96433465e 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -135,7 +135,11 @@ def id
     end
 
     def json_api_type
-      object.class.model_name.plural
+      if config.jsonapi_resource_type == :plural
+        object.class.model_name.plural
+      else
+        object.class.model_name.singular
+      end
     end
 
     def attributes(options = {})
diff --git a/lib/active_model/serializer/configuration.rb b/lib/active_model/serializer/configuration.rb
index 86df706e1..102c821e1 100644
--- a/lib/active_model/serializer/configuration.rb
+++ b/lib/active_model/serializer/configuration.rb
@@ -7,6 +7,7 @@ module Configuration
       included do |base|
         base.config.array_serializer = ActiveModel::Serializer::ArraySerializer
         base.config.adapter = :flatten_json
+        base.config.jsonapi_resource_type = :plural
       end
     end
   end
diff --git a/test/adapter/json_api/resource_type_config_test.rb b/test/adapter/json_api/resource_type_config_test.rb
new file mode 100644
index 000000000..e389b9b4f
--- /dev/null
+++ b/test/adapter/json_api/resource_type_config_test.rb
@@ -0,0 +1,59 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class Adapter
+      class JsonApi
+        class ResourceTypeConfigTest < Minitest::Test
+          def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
+            @author.bio = nil
+            @author.roles = []
+            @blog = Blog.new(id: 23, name: 'AMS Blog')
+            @post = Post.new(id: 42, title: 'New Post', body: 'Body')
+            @anonymous_post = Post.new(id: 43, title: 'Hello!!', body: 'Hello, world!!')
+            @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+            @post.comments = [@comment]
+            @post.blog = @blog
+            @anonymous_post.comments = []
+            @anonymous_post.blog = nil
+            @comment.post = @post
+            @comment.author = nil
+            @post.author = @author
+            @anonymous_post.author = nil
+            @blog = Blog.new(id: 1, name: "My Blog!!")
+            @blog.writer = @author
+            @blog.articles = [@post, @anonymous_post]
+            @author.posts = []
+          end
+
+          def with_jsonapi_resource_type type
+            old_type = ActiveModel::Serializer.config[:jsonapi_resource_type]
+            ActiveModel::Serializer.config[:jsonapi_resource_type] = type
+            yield
+          ensure
+            ActiveModel::Serializer.config[:jsonapi_resource_type] = old_type
+          end
+
+          def test_config_plural
+            with_jsonapi_resource_type :plural do
+              serializer = CommentSerializer.new(@comment)
+              adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+              ActionController::Base.cache_store.clear
+              assert_equal('comments', adapter.serializable_hash[:data][:type])
+            end
+          end
+
+          def test_config_singular
+            with_jsonapi_resource_type :singular do
+              serializer = CommentSerializer.new(@comment)
+              adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+              ActionController::Base.cache_store.clear
+              assert_equal('comment', adapter.serializable_hash[:data][:type])
+            end
+          end
+        end
+      end
+    end
+  end
+end