Add PreloadExtension

lib/phantom/graphql.rb

@@ -1,14 +1,17 @@
 # frozen_string_literal: true
 
 require "graphql"
+require "batch-loader"
 
 module Phantom::Graphql
 end
 
-require "phantom/graphql/authorization"
+require "phantom/graphql/field_extensions"
 require "phantom/graphql/enum"
 require "phantom/graphql/response"
 
+GraphQL::Schema.use(BatchLoader::GraphQL)
+
 GraphQL::Schema::InputObject.extend(Phantom::Graphql::Enum)
 GraphQL::Schema::Object.extend(Phantom::Graphql::Enum)
 GraphQL::Schema::RelayClassicMutation.extend(Phantom::Graphql::Enum)

lib/phantom/graphql/field_extensions.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Phantom::Graphql::FieldExtensions
+  class AuthorizeExtension < GraphQL::Schema::FieldExtension
+    def resolve(context:, object:, arguments:, **_rest)
+      name, action = options.split("#")
+
+      authorized = name.constantize.new(context[:current_session]).send(action)
+
+      raise GraphQL::ExecutionError, "Unauthorized" unless authorized
+
+      yield object, arguments
+    end
+  end
+
+  class PreloadExtension < GraphQL::Schema::FieldExtension
+    def resolve(context:, object:, arguments:, **rest)
+      BatchLoader::GraphQL.for(object).batch(key: field) do |records, loader|
+        scope = options[:scope].constantize.new(context[:current_session]).scope if options[:scope].present?
+        ActiveRecord::Associations::Preloader.new(records: records.map(&:object), associations: options[:preload]).call
+        records.each { |r| loader.call(r, super(context: context, object: r, arguments: arguments, **rest)) }
+      end
+    end
+  end
+
+  def initialize(*args, authorize: nil, preload: nil, scope: nil, **kwargs, &block)
+    extensions = (kwargs[:extensions] ||= [])
+
+    extensions << { Phantom::Graphql::FieldExtensions::AuthorizeExtension => authorize } if authorize.present?
+    extensions << { Phantom::Graphql::FieldExtensions::PreloadExtension => { preload: preload, scope: scope } } if preload.present?
+
+    super(*args, **kwargs, &block)
+  end
+end

phantom.gemspec

@@ -14,6 +14,6 @@ Gem::Specification.new do |s|
   s.metadata["rubygems_mfa_required"] = "true"
 
   s.required_ruby_version = ">= 3.1"
+  s.add_dependency "batch-loader"
   s.add_dependency "graphql"
-  s.add_dependency "minitest"
 end