Switch to GraphQL's Dataloader

Author: trmcnvn

Gemfile.lock

@@ -1,20 +1,21 @@
 # GraphQL::FancyLoader
 
-FancyLoader (built on top of the [graphql-batch][graphql-batch] gem) efficiently batches queries
+> [!NOTE]
+> This is a fork of the original [hummingbird-me/graphql-fancy-loader](https://github.com/hummingbird-me/graphql-fancy-loader) that has been migrated to use graphql-ruby's built-in dataloader instead of graphql-batch. If you need the original graphql-batch implementation, please use the upstream repository.
+
+FancyLoader (built on top of graphql-ruby's dataloader) efficiently batches queries
 using postgres window functions to allow advanced features such as orders, limits, pagination, and
 authorization scoping. Built on top of Arel, FancyLoader is highly extensible and capable of
 handling complex sorts (including sorting based on a join) with minimal effort and high performance.
 
 We use FancyLoader in production to power large swaths of the Kitsu GraphQL API.
 
-[graphql-batch]: https://github.com/Shopify/graphql-batch
-
 ## Installation
 
 Add this line to your application's Gemfile:
 
 ```ruby
-gem 'graphql-fancy_loader'
+gem 'graphql-fancy_loader', github: 'metafy-gg/graphql-fancy-loader'
 ```
 
 And then execute:
@@ -23,12 +24,6 @@ And then execute:
 $ bundle install
 ```
 
-Or install it yourself as:
-
-```
-$ gem install graphql-fancy_loader
-```
-
 ## Basic Usage
 
 ### Defining a Loader
@@ -54,7 +49,7 @@ end
 
 This loader class provides two primary methods: `.sort_argument` and `.connection_for`.
 `.sort_argument` gives you a convenient auto-generated sort field which allows for multiple sorts.
-`.connection_for` is a wrapper around graphql-batch which returns a connection. Pagination will be
+`.connection_for` is a wrapper around graphql-ruby's dataloader which returns a connection. Pagination will be
 automatically applied to this connection by the graphql gem, so you just need to pass in your other
 options:
 
@@ -77,8 +72,7 @@ end
 
 ### Testing the Loader
 
-Testing a FancyLoader is pretty much exactly the same as testing any other graphql-batch Loader
-class:
+Testing a FancyLoader works with graphql-ruby's dataloader pattern:
 
 ```ruby
 RSpec.describe Loaders::PostsLoader do
@@ -90,13 +84,11 @@ RSpec.describe Loaders::PostsLoader do
   let(:sort) { [{ on: :created_at, direction: :desc }] }
 
   it 'loads all the posts for a user' do
-    posts = GraphQL::Batch.batch do
-      described_class.connection_for({
-        find_by: :user_id,
-        sort: sort,
-        context: context
-      }, user.id).nodes
-    end
+    posts = described_class.connection_for({
+      find_by: :user_id,
+      sort: sort,
+      context: context
+    }, user.id).nodes
 
     expect(posts.count).to eq(user.posts.count)
   end
@@ -208,7 +200,7 @@ will create a git tag for the version, push git commits and tags, and push the `
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at
-https://github.com/hummingbird-me/graphql-fancy-loader.
+https://github.com/metafy-gg/graphql-fancy-loader.
 
 ## License
 

README.md

@@ -6,35 +6,34 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'graphql/fancy_loader/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = 'graphql-fancy_loader'
-  spec.version       = GraphQL::FancyLoader::VERSION
-  spec.authors       = ['Toyhammered', 'Emma Lejeck']
-  spec.email         = ['[email protected]']
+  spec.name = 'graphql-fancy_loader'
+  spec.version = GraphQL::FancyLoader::VERSION
+  spec.authors = ['Toyhammered', 'Emma Lejeck', 'Thomas McNiven']
+  spec.email = ['[email protected]', '[email protected]']
 
-  spec.summary       = 'FancyLoader efficiently batches queries using postgres window functions to allow advanced features such as orders, limits, pagination, and authorization scoping.'
-  spec.description   = 'FancyLoader (built on top of the graphql-batch gem) efficiently batches queries using postgres window functions to allow advanced features such as orders, limits, pagination, and authorization scoping. Built on top of Arel, FancyLoader is highly extensible and capable of handling complex sorts (including sorting based on a join) with minimal effort and high performance.'
-  spec.homepage      = 'https://github.com/hummingbird-me/graphql-fancy-loader'
-  spec.license       = 'Apache-2.0'
+  spec.summary = 'FancyLoader efficiently batches queries using postgres window functions to allow advanced features such as orders, limits, pagination, and authorization scoping.'
+  spec.description = "FancyLoader (built on top of graphql-ruby's dataloader) efficiently batches queries using postgres window functions to allow advanced features such as orders, limits, pagination, and authorization scoping. Built on top of Arel, FancyLoader is highly extensible and capable of handling complex sorts (including sorting based on a join) with minimal effort and high performance."
+  spec.homepage = 'https://github.com/metafy-gg/graphql-fancy-loader'
+  spec.license = 'Apache-2.0'
 
   spec.metadata['homepage_uri'] = spec.homepage
-  spec.metadata['source_code_uri'] = 'https://github.com/hummingbird-me/graphql-fancy-loader'
+  spec.metadata['source_code_uri'] = 'https://github.com/metafy-gg/graphql-fancy-loader'
   spec.metadata['allowed_push_host'] = 'https://rubygems.org'
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
   spec.files = Dir.chdir(File.expand_path(__dir__)) do
     `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
   end
-  spec.bindir        = 'exe'
-  spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
+  spec.bindir = 'exe'
+  spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
   spec.add_runtime_dependency 'activesupport', '>= 5.0', '< 9.0'
-  spec.add_runtime_dependency 'graphql', '>= 1.3', '< 3'
-  spec.add_runtime_dependency 'graphql-batch', '>= 0.4.3', '< 1'
+  spec.add_runtime_dependency 'graphql', '>= 1.8', '< 3'
 
-  spec.add_development_dependency 'bundler', '~> 2.0'
-  spec.add_development_dependency 'pry-byebug', '~> 3.10'
+  spec.add_development_dependency 'bundler', '>= 2.0'
+  spec.add_development_dependency 'pry-byebug', '~> 3.11'
   spec.add_development_dependency 'rake', '>= 13.2'
   spec.add_development_dependency 'rspec', '~> 3.13'
   spec.add_development_dependency 'simplecov', '~> 0.22'
@@ -43,8 +42,8 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bootsnap', '~> 1.18'
   spec.add_development_dependency 'database_cleaner', '~> 2.1'
   spec.add_development_dependency 'factory_bot_rails', '~> 6.4'
-  spec.add_development_dependency 'listen', '~> 3.9'
+  spec.add_development_dependency 'listen', '>= 3.9'
   spec.add_development_dependency 'pg', '~> 1.5'
-  spec.add_development_dependency 'rails', '8.0'
-  spec.add_development_dependency 'rspec-rails', '~> 7.0'
+  spec.add_development_dependency 'rails', '>= 8.0'
+  spec.add_development_dependency 'rspec-rails', '>= 7.0'
 end

graphql-fancy_loader.gemspec

@@ -9,64 +9,61 @@ def initialize(loader, args, key, **super_args)
       super(nil, **super_args)
     end
 
-    # @return [Promise<Array<ApplicationRecord>>]
+    # @return [Array<ApplicationRecord>]
     def nodes
+      resolved_nodes = base_nodes
       if @then
-        base_nodes.then(@then)
+        @then.call(resolved_nodes)
       else
-        base_nodes
+        resolved_nodes
       end
     end
 
     def edges
-      @edges ||= nodes.then do |nodes|
-        nodes.map { |n| @edge_class.new(n, self) }
+      @edges ||= begin
+        resolved_nodes = nodes
+        resolved_nodes.map { |n| @edge_class.new(n, self) }
       end
     end
 
-    # @return [Promise<Integer>]
+    # @return [Integer]
     def total_count
-      base_nodes.then do |results|
-        if results.first
-          results.first.attributes['total_count']
-        else
-          0
-        end
+      results = base_nodes
+      if results.first
+        results.first.attributes['total_count']
+      else
+        0
       end
     end
 
-    # @return [Promise<Boolean>]
+    # @return [Boolean]
     def has_next_page # rubocop:disable Naming/PredicateName
-      base_nodes.then do |results|
-        if results.last
-          results.last.attributes['row_number'] < results.last.attributes['total_count']
-        else
-          false
-        end
+      results = base_nodes
+      if results.last
+        results.last.attributes['row_number'] < results.last.attributes['total_count']
+      else
+        false
       end
     end
 
-    # @return [Promise<Boolean>]
+    # @return [Boolean]
     def has_previous_page # rubocop:disable Naming/PredicateName
-      base_nodes.then do |results|
-        if results.first
-          results.first.attributes['row_number'] > 1
-        else
-          false
-        end
+      results = base_nodes
+      if results.first
+        results.first.attributes['row_number'] > 1
+      else
+        false
       end
     end
 
     def start_cursor
-      base_nodes.then do |results|
-        cursor_for(results.first)
-      end
+      results = base_nodes
+      cursor_for(results.first)
     end
 
     def end_cursor
-      base_nodes.then do |results|
-        cursor_for(results.last)
-      end
+      results = base_nodes
+      cursor_for(results.last)
     end
 
     def cursor_for(item)
@@ -81,7 +78,7 @@ def then(&block)
     private
 
     def base_nodes
-      @base_nodes ||= @loader.for(**loader_args).load(@key)
+      @base_nodes ||= context.dataloader.with(@loader, **loader_args).load(@key)
     end
 
     def after_offset

lib/graphql/fancy_connection.rb

@@ -5,18 +5,19 @@
 # To use +FancyLoader+, you'll make a subclass to define your sorts and source model. You can then
 # create a field which uses your subclass to load data.
 
-require 'graphql/batch'
+require 'graphql/dataloader'
 require 'active_support'
 require 'active_support/concern'
 require 'active_support/configurable'
 require 'active_support/core_ext/class/attribute'
 
+require 'graphql/fancy_loader/version'
 require 'graphql/fancy_loader/dsl'
 
 module GraphQL
-  class FancyLoader < GraphQL::Batch::Loader
+  class FancyLoader < GraphQL::Dataloader::Source
     include ActiveSupport::Configurable
-    include GraphQL::FancyLoader::DSL
+    include DSL
 
     config_accessor :middleware
 
@@ -61,8 +62,8 @@ def initialize(find_by:, sort:, before: nil, after: 0, first: nil, last: nil, wh
     end
 
     # Perform the loading. Uses {GraphQL::FancyLoader::QueryGenerator} to build a query, then groups
-    # the results by the @find_by column, then fulfills all the Promises.
-    def perform(keys)
+    # the results by the @find_by column, then returns the grouped results.
+    def fetch(keys)
       query = QueryGenerator.new(
         model: model,
         find_by: @find_by,
@@ -78,9 +79,7 @@ def perform(keys)
       ).query
 
       results = query.to_a.group_by { |rec| rec[@find_by] }
-      keys.each do |key|
-        fulfill(key, results[key] || [])
-      end
+      keys.map { |key| results[key] || [] }
     end
 
     private
@@ -100,6 +99,5 @@ def sort
 require 'graphql/fancy_loader/query_generator'
 require 'graphql/fancy_loader/rank_query_generator'
 require 'graphql/fancy_loader/type_generator'
-require 'graphql/fancy_loader/version'
 # Middleware
 require 'graphql/fancy_loader/pundit_middleware'

lib/graphql/fancy_loader.rb

@@ -1,5 +1,5 @@
 module GraphQL
-  class FancyLoader < GraphQL::Batch::Loader
+  class FancyLoader
     module DSL
       extend ActiveSupport::Concern
 

lib/graphql/fancy_loader/dsl.rb

@@ -1,11 +1,10 @@
 module GraphQL
-  # HACK: This allows us to import the version number in the gemspec
   class FancyLoader < (begin
-    require 'graphql/batch'
-    GraphQL::Batch::Loader
+    require 'graphql/dataloader'
+    GraphQL::Dataloader::Source
   rescue LoadError
     BasicObject
   end)
-    VERSION = '0.1.6'.freeze # .3
+    VERSION = '0.2.0'.freeze
   end
 end

lib/graphql/fancy_loader/version.rb

@@ -1,6 +1,8 @@
 default: &default
   adapter: postgresql
   encoding: unicode
+  host: localhost
+  port: 5432
   prepared_statements: false
   advisory_locks: false
 <% if ENV.include?('DATABASE_URL') %>

spec/dummy/config/database.yml

@@ -10,24 +10,23 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_10_17_215654) do
-
+ActiveRecord::Schema[8.0].define(version: 2021_10_17_215654) do
   # These are extensions that must be enabled in order to support this database
-  enable_extension "plpgsql"
+  enable_extension "pg_catalog.plpgsql"
 
   create_table "posts", force: :cascade do |t|
     t.bigint "user_id"
     t.string "title", null: false
     t.string "description"
-    t.datetime "created_at", precision: 6, null: false
-    t.datetime "updated_at", precision: 6, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
     t.index ["user_id"], name: "index_posts_on_user_id"
   end
 
   create_table "users", force: :cascade do |t|
     t.string "email", null: false
-    t.datetime "created_at", precision: 6, null: false
-    t.datetime "updated_at", precision: 6, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
   end
 
   add_foreign_key "posts", "users"