Add symbol support for ActiveModel::Serializer.type method

The ActiveModel::Serializer.type method now accepts symbol as paremeter:
class AuthorSerializer < ActiveModel::Serializer
  type :profile
end
The test file for the type was also refactored.

CHANGELOG.md

@@ -3,6 +3,8 @@
 Breaking changes:
 
 Features:
+- [#1515](https://github.com/rails-api/active_model_serializers/pull/1515) Adds support for symbols to the
+  `ActiveModel::Serializer.type` method. (@groyoh)
 - [#1504](https://github.com/rails-api/active_model_serializers/pull/1504) Adds the changes missing from #1454
   and add more tests for resource identifier and relationship objects. Fix association block with link
   returning `data: nil`.(@groyoh)

docs/general/serializers.md

@@ -107,12 +107,30 @@ end
 
 #### ::type
 
-e.g.
+The `::type` method defines the JSONAPI [type](http://jsonapi.org/format/#document-resource-object-identification) that will be rendered for this serializer.
+It either takes a `String` or `Symbol` as parameter.
 
+Note: This method is useful only when using the `:json_api` adapter.
+
+Examples:
 ```ruby
 class UserProfileSerializer < ActiveModel::Serializer
   type 'profile'
 end
+class AuthorProfileSerializer < ActiveModel::Serializer
+  type :profile
+end
+```
+
+With the `:json_api` adapter, the previous serializers would be rendered as:
+
+``` json
+{
+  "data": {
+    "id": "1",
+    "type": "profile"
+  }
+}
 ```
 
 #### ::link

lib/active_model/serializer/type.rb

@@ -17,7 +17,7 @@ module ActiveModel
         #   class AdminAuthorSerializer < ActiveModel::Serializer
         #     type 'authors'
         def type(type)
-          self._type = type
+          self._type = type && type.to_s
         end
       end
     end

test/adapter/json_api/resource_type_config_test.rb

@@ -1,71 +0,0 @@
-require 'test_helper'
-
-module ActiveModel
-  class Serializer
-    module Adapter
-      class JsonApi
-        class ResourceTypeConfigTest < ActiveSupport::TestCase
-          class ProfileTypeSerializer < ActiveModel::Serializer
-            attributes :name
-            type 'profile'
-          end
-
-          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 = ActiveModelSerializers.config.jsonapi_resource_type
-            ActiveModelSerializers.config.jsonapi_resource_type = type
-            yield
-          ensure
-            ActiveModelSerializers.config.jsonapi_resource_type = old_type
-          end
-
-          def test_config_plural
-            with_jsonapi_resource_type :plural do
-              hash = serializable(@comment, adapter: :json_api).serializable_hash
-              assert_equal('comments', hash[:data][:type])
-            end
-          end
-
-          def test_config_singular
-            with_jsonapi_resource_type :singular do
-              hash = serializable(@comment, adapter: :json_api).serializable_hash
-              assert_equal('comment', hash[:data][:type])
-            end
-          end
-
-          def test_explicit_type_value
-            hash = serializable(@author, serializer: ProfileTypeSerializer, adapter: :json_api).serializable_hash
-            assert_equal('profile', hash.fetch(:data).fetch(:type))
-          end
-
-          private
-
-          def serializable(resource, options = {})
-            ActiveModel::SerializableResource.new(resource, options)
-          end
-        end
-      end
-    end
-  end
-end

test/adapter/json_api/type_test.rb

@@ -0,0 +1,61 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    module Adapter
+      class JsonApi
+        class TypeTest < ActiveSupport::TestCase
+          class StringTypeSerializer < ActiveModel::Serializer
+            attribute :name
+            type 'profile'
+          end
+
+          class SymbolTypeSerializer < ActiveModel::Serializer
+            attribute :name
+            type :profile
+          end
+
+          setup do
+            @author = Author.new(id: 1, name: 'Steve K.')
+          end
+
+          def test_config_plural
+            with_jsonapi_resource_type :plural do
+              assert_type(@author, 'authors')
+            end
+          end
+
+          def test_config_singular
+            with_jsonapi_resource_type :singular do
+              assert_type(@author, 'author')
+            end
+          end
+
+          def test_explicit_string_type_value
+            assert_type(@author, 'profile', serializer: StringTypeSerializer)
+          end
+
+          def test_explicit_symbol_type_value
+            assert_type(@author, 'profile', serializer: SymbolTypeSerializer)
+          end
+
+          private
+
+          def assert_type(resource, expected_type, opts = {})
+            opts = opts.reverse_merge(adapter: :json_api)
+            hash = serializable(resource, opts).serializable_hash
+            assert_equal(expected_type, hash.fetch(:data).fetch(:type))
+          end
+
+          def with_jsonapi_resource_type inflection
+            old_inflection = ActiveModelSerializers.config.jsonapi_resource_type
+            ActiveModelSerializers.config.jsonapi_resource_type = inflection
+            yield
+          ensure
+            ActiveModelSerializers.config.jsonapi_resource_type = old_inflection
+          end
+        end
+      end
+    end
+  end
+end