Assert Schema (#1677)

* Assert Schema

* Fix regression from #1695 where JSONAPI renders empty meta

* Add changelog

CHANGELOG.md

@@ -6,6 +6,7 @@ Breaking changes:
 - [#1662](https://github.com/rails-api/active_model_serializers/pull/1662) Drop support for Rails 4.0 and Ruby 2.0.0. (@remear)
 
 Features:
+- [#1677](https://github.com/rails-api/active_model_serializers/pull/1677) Add `assert_schema`, `assert_request_schema`, `assert_request_response_schema`. (@bf4)
 - [#1697](https://github.com/rails-api/active_model_serializers/pull/1697) Include actual exception message with custom exceptions;
   `Test::Schema` exceptions are now `Minitest::Assertion`s. (@bf4)
 - [#1699](https://github.com/rails-api/active_model_serializers/pull/1699) String/Lambda support for conditional attributes/associations (@mtsmfm)

lib/active_model_serializers/adapter/json_api.rb

@@ -131,7 +131,7 @@ module ActiveModelSerializers
           hash[:links].update(pagination_links_for(serializer))
         end
 
-        hash[:meta] = instance_options[:meta] if instance_options[:meta].is_a?(Hash)
+        hash[:meta] = instance_options[:meta] unless instance_options[:meta].blank?
 
         hash
       end

lib/active_model_serializers/test/schema.rb

@@ -10,19 +10,38 @@ module ActiveModelSerializers
       #   get :index
       #   assert_response_schema
       def assert_response_schema(schema_path = nil, message = nil)
-        matcher = AssertResponseSchema.new(schema_path, response, message)
+        matcher = AssertResponseSchema.new(schema_path, request, response, message)
+        assert(matcher.call, matcher.message)
+      end
+
+      def assert_request_schema(schema_path = nil, message = nil)
+        matcher = AssertRequestSchema.new(schema_path, request, response, message)
+        assert(matcher.call, matcher.message)
+      end
+
+      # May be renamed
+      def assert_request_response_schema(schema_path = nil, message = nil)
+        assert_request_schema(schema_path, message)
+        assert_response_schema(schema_path, message)
+      end
+
+      def assert_schema(payload, schema_path = nil, message = nil)
+        matcher = AssertSchema.new(schema_path, request, response, message, payload)
         assert(matcher.call, matcher.message)
       end
 
       MissingSchema = Class.new(Minitest::Assertion)
       InvalidSchemaError = Class.new(Minitest::Assertion)
 
-      class AssertResponseSchema
+      class AssertSchema
-        attr_reader :schema_path, :response, :message
+        attr_reader :schema_path, :request, :response, :message, :payload
 
-        def initialize(schema_path, response, message)
+        # Interface may change.
+        def initialize(schema_path, request, response, message, payload = nil)
           require_json_schema!
+          @request = request
           @response = response
+          @payload = payload
           @schema_path = schema_path || schema_path_default
           @message = message
           @document_store = JsonSchema::DocumentStore.new
@@ -41,11 +60,11 @@ module ActiveModelSerializers
         attr_reader :document_store
 
         def controller_path
-          response.request.filtered_parameters[:controller]
+          request.filtered_parameters[:controller]
         end
 
         def action
-          response.request.filtered_parameters[:action]
+          request.filtered_parameters[:action]
         end
 
         def schema_directory
@@ -68,6 +87,10 @@ module ActiveModelSerializers
           load_json(response.body)
         end
 
+        def request_params
+          request.env['action_dispatch.request.request_parameters']
+        end
+
         def json_schema
           @json_schema ||= JsonSchema.parse!(schema_data)
         end
@@ -98,6 +121,18 @@ module ActiveModelSerializers
           raise LoadError, "You don't have json_schema installed in your application. Please add it to your Gemfile and run bundle install"
         end
       end
+      class AssertResponseSchema < AssertSchema
+        def initialize(*)
+          super
+          @payload = response_body
+        end
+      end
+      class AssertRequestSchema < AssertSchema
+        def initialize(*)
+          super
+          @payload = request_params
+        end
+      end
     end
   end
 end

test/serializers/meta_test.rb

@@ -110,7 +110,7 @@ module ActiveModel
         assert_equal(expected, actual)
       end
 
-      def test_meta_key_is_present_when_empty_hash_with_json_api
+      def test_meta_key_is_not_present_when_empty_hash_with_json_api
         actual = ActiveModelSerializers::SerializableResource.new(
           @blog,
           adapter: :json_api,
@@ -122,8 +122,7 @@ module ActiveModel
             id: '1',
             type: 'blogs',
             attributes: { title: 'AMS Hints' }
-          },
+          }
-          meta: {}
         }
         assert_equal(expected, actual)
       end