Use the dataloader and remove dependency on graphql-batch

Author: rzane

README.md

@@ -14,8 +14,8 @@ A collection of utilities for building GraphQL APIs.
 - [Installation](#installation)
 - [Usage](#usage)
   - [GraphQL::Extras::Controller](#graphqlextrascontroller)
-  - [GraphQL::Extras::AssociationLoader](#graphqlextrasassociationloader)
   - [GraphQL::Extras::Preload](#graphqlextraspreload)
+  - [GraphQL::Extras::PreloadSource](#graphqlextraspreloadsource)
   - [GraphQL::Extras::Types](#graphqlextrastypes)
     - [Date](#date)
     - [DateTime](#datetime)
@@ -53,21 +53,15 @@ class GraphqlController < ApplicationController
 end
 ```
 
-### GraphQL::Extras::AssociationLoader
-
-This is a subclass of [`GraphQL::Batch::Loader`](https://github.com/Shopify/graphql-batch) that performs eager loading of Active Record associations.
-
-```ruby
-loader = GraphQL::Extras::AssociationLoader.for(:blog)
-loader.load(Post.first)
-loader.load_many(Post.all)
-```
-
 ### GraphQL::Extras::Preload
 
 This allows you to preload associations before resolving fields.
 
 ```ruby
+class Schema < GraphQL::Schema
+  use GraphQL::Dataloader
+end
+
 class BaseField < GraphQL::Schema::Field
   prepend GraphQL::Extras::Preload
 end
@@ -87,6 +81,16 @@ class PostType < BaseObject
 end
 ```
 
+### GraphQL::Extras::PreloadSource
+
+This is a subclass of [`GraphQL::Dataloader::Source`](https://graphql-ruby.org/dataloader/overview.html) that performs eager loading of Active Record associations.
+
+```ruby
+loader = dataloader.with(GraphQL::Extras::PreloadSource, :blog)
+loader.load(Post.first)
+loader.load_many(Post.all)
+```
+
 ### GraphQL::Extras::Types
 
 In your base classes, you should include the `GraphQL::Extras::Types`.

graphql-extras.gemspec

@@ -26,7 +26,6 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "activesupport", ">= 5.2"
   spec.add_dependency "graphql", "~> 1.12"
-  spec.add_dependency "graphql-batch", "~> 0.4"
 
   spec.add_development_dependency "bundler", "~> 2.0"
   spec.add_development_dependency "rake", "~> 13.0"

lib/graphql/extras.rb

@@ -1,7 +1,6 @@
 require "graphql/extras/version"
 require "graphql/extras/types"
 require "graphql/extras/controller"
-require "graphql/extras/association_loader"
 require "graphql/extras/preload"
 
 module GraphQL

lib/graphql/extras/association_loader.rb

@@ -1,7 +1,17 @@
-require "graphql/extras/association_loader"
-
 module GraphQL
   module Extras
+    class PreloadSource < GraphQL::Dataloader::Source
+      def initialize(preload)
+        @preload = preload
+      end
+
+      def fetch(records)
+        preloader = ActiveRecord::Associations::Preloader.new
+        preloader.preload(records, @preload)
+        records
+      end
+    end
+
     module Preload
       # @override
       def initialize(*args, preload: nil, **opts, &block)
@@ -10,13 +20,13 @@ def initialize(*args, preload: nil, **opts, &block)
       end
 
       # @override
-      def resolve(object, args, ctx)
-        return super unless @preload
-
-        loader = AssociationLoader.for(@preload)
-        loader.load(object.object).then do
-          super(object, args, ctx)
+      def resolve(object, args, context)
+        if @preload
+          loader = context.dataloader.with(PreloadSource, @preload)
+          loader.load(object.object)
         end
+
+        super
       end
     end
   end

lib/graphql/extras/preload.rb

@@ -34,7 +34,7 @@ def bars_batched; Bar.all; end
 
   class BatchSchema < GraphQL::Schema
     query BatchQueryType
-    use GraphQL::Batch
+    use GraphQL::Dataloader
   end
 
   before :all do