Use GraphQL for your data #38

Dockerfile

@@ -1,5 +1,5 @@
 FROM ruby:2.6
-RUN apt-get update -qq && apt-get install -y nodejs postgresql-client
+RUN apt-get update -qq && apt-get install -y postgresql-client
 RUN mkdir /myapp
 WORKDIR /myapp
 COPY Gemfile /myapp/Gemfile

Gemfile

@@ -32,6 +32,9 @@ gem 'omniauth-google-oauth2'
 gem 'omniauth-twitter'
 gem 'omniauth-discord'
 
+# Data Management (GraphQL)
+gem 'graphql', '1.8.13'
+
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
@@ -42,6 +45,8 @@ group :development do
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem 'spring'
   gem 'spring-watcher-listen', '~> 2.0.0'
+  # GraphQL Testing
+  gem 'graphiql-rails', '1.5.0'
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem

Gemfile.lock

@@ -79,6 +79,10 @@ GEM
     ffi (1.11.1)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
+    graphiql-rails (1.5.0)
+      railties
+      sprockets-rails
+    graphql (1.8.13)
     hashie (3.6.0)
     i18n (1.7.0)
       concurrent-ruby (~> 1.0)
@@ -205,6 +209,8 @@ DEPENDENCIES
   bootsnap (>= 1.4.2)
   byebug
   devise_token_auth
+  graphiql-rails (= 1.5.0)
+  graphql (= 1.8.13)
   listen (>= 3.0.5, < 3.2)
   omniauth-discord
   omniauth-facebook

README.md

@@ -7,6 +7,7 @@ The back-end of Kuru Anime
 
 ## Core Gems
 - [Devise Token Auth](https://github.com/lynndylanhurley/devise_token_auth) (Authentication)
+- [GraphQL](https://graphql-ruby.org/) (Data Management) [[Tutorial](https://www.howtographql.com/graphql-ruby/0-introduction/)]
 
 ## Set-up
 You need to have **Docker** and **Docker Compose** installed on your machine to be able to run the following commands.

app/controllers/application_controller.rb

@@ -1,4 +1,2 @@
 class ApplicationController < ActionController::API
-  include DeviseTokenAuth::Concerns::SetUserByToken
-  before_action :authenticate_user!
 end

app/controllers/graphql_controller.rb

@@ -0,0 +1,46 @@
+class GraphqlController < ApplicationController
+  include DeviseTokenAuth::Concerns::SetUserByToken
+  before_action :authenticate_user!
+
+  def execute
+    variables = ensure_hash(params[:variables])
+    query = params[:query]
+    operation_name = params[:operationName]
+    context = {
+      # Query context goes here, for example:
+      # current_user: current_user,
+    }
+    result = MyappSchema.execute(query, variables: variables, context: context, operation_name: operation_name)
+    render json: result
+  rescue => e
+    raise e unless Rails.env.development?
+    handle_error_in_development e
+  end
+
+  private
+
+  # Handle form data, JSON body, or a blank value
+  def ensure_hash(ambiguous_param)
+    case ambiguous_param
+    when String
+      if ambiguous_param.present?
+        ensure_hash(JSON.parse(ambiguous_param))
+      else
+        {}
+      end
+    when Hash, ActionController::Parameters
+      ambiguous_param
+    when nil
+      {}
+    else
+      raise ArgumentError, "Unexpected parameter: #{ambiguous_param}"
+    end
+  end
+
+  def handle_error_in_development(e)
+    logger.error e.message
+    logger.error e.backtrace.join("\n")
+
+    render json: { error: { message: e.message, backtrace: e.backtrace }, data: {} }, status: 500
+  end
+end

app/graphql/mutations/base_mutation.rb

@@ -0,0 +1,6 @@
+module Mutations
+  # This class is used as a parent for all mutations, and it is the place to have common utilities
+  class BaseMutation < GraphQL::Schema::Mutation
+    null false
+  end
+end

app/graphql/mutations/create_link.rb

@@ -0,0 +1,17 @@
+module Mutations
+  class CreateLink < BaseMutation
+    # arguments passed to the `resolved` method
+    argument :description, String, required: true
+    argument :url, String, required: true
+
+    # return type from the mutation
+    type Types::LinkType
+
+    def resolve(description: nil, url: nil)
+      Link.create!(
+        description: description,
+        url: url,
+      )
+    end
+  end
+end

app/graphql/myapp_schema.rb

@@ -0,0 +1,4 @@
+class MyappSchema < GraphQL::Schema
+  mutation(Types::MutationType)
+  query(Types::QueryType)
+end

app/graphql/types/base_enum.rb

@@ -0,0 +1,4 @@
+module Types
+  class BaseEnum < GraphQL::Schema::Enum
+  end
+end

app/graphql/types/base_input_object.rb

@@ -0,0 +1,4 @@
+module Types
+  class BaseInputObject < GraphQL::Schema::InputObject
+  end
+end

app/graphql/types/base_interface.rb

@@ -0,0 +1,5 @@
+module Types
+  module BaseInterface
+    include GraphQL::Schema::Interface
+  end
+end

app/graphql/types/base_object.rb

@@ -0,0 +1,4 @@
+module Types
+  class BaseObject < GraphQL::Schema::Object
+  end
+end

app/graphql/types/base_scalar.rb

@@ -0,0 +1,4 @@
+module Types
+  class BaseScalar < GraphQL::Schema::Scalar
+  end
+end

app/graphql/types/base_union.rb

@@ -0,0 +1,4 @@
+module Types
+  class BaseUnion < GraphQL::Schema::Union
+  end
+end

app/graphql/types/link_type.rb

@@ -0,0 +1,7 @@
+module Types
+  class LinkType < Types::BaseObject
+    field :id, ID, null: false
+    field :url, String, null: false
+    field :description, String, null: false
+  end
+end

app/graphql/types/mutation_type.rb

@@ -0,0 +1,5 @@
+module Types
+  class MutationType < Types::BaseObject
+    field :create_link, mutation: Mutations::CreateLink
+  end
+end

app/graphql/types/query_type.rb

@@ -0,0 +1,12 @@
+module Types
+  class QueryType < Types::BaseObject
+    # queries are just represented as fields
+    # `all_links` is automatically camelcased to `allLinks`
+    field :all_links, [LinkType], null: false
+
+    # this method is invoked, when `all_link` fields is being resolved
+    def all_links
+      Link.all
+    end
+  end
+end

app/models/link.rb

@@ -0,0 +1,2 @@
+class Link < ApplicationRecord
+end

config/application.rb

@@ -12,7 +12,7 @@
 require "action_text/engine"
 require "action_view/railtie"
 require "action_cable/engine"
-# require "sprockets/railtie"
+require "sprockets/railtie"
 require "rails/test_unit/railtie"
 
 # Require the gems listed in Gemfile, including any gems

config/routes.rb

@@ -1,4 +1,13 @@
 Rails.application.routes.draw do
-  mount_devise_token_auth_for 'User', at: 'auth'
+  # Base Redirect
   root to: redirect("https://web.kuru-anime.com/")
+
+  # Authentication
+  mount_devise_token_auth_for 'User', at: 'auth'
+
+  # Data Management (GraphQL)
+  post "/data", to: "graphql#execute"
+  if Rails.env.development?
+    mount GraphiQL::Rails::Engine, at: "/graphiql", graphql_path: "/data"
+  end
 end

db/migrate/20200112101032_create_links.rb

@@ -0,0 +1,10 @@
+class CreateLinks < ActiveRecord::Migration[6.0]
+  def change
+    create_table :links do |t|
+      t.string :url
+      t.text :description
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,11 +10,18 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_10_09_000354) do
+ActiveRecord::Schema.define(version: 2020_01_12_101032) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
+  create_table "links", force: :cascade do |t|
+    t.string "url"
+    t.text "description"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+  end
+
   create_table "users", force: :cascade do |t|
     t.string "provider", default: "email", null: false
     t.string "uid", default: "", null: false

test/fixtures/links.yml

@@ -0,0 +1,9 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  url: MyString
+  description: MyText
+
+two:
+  url: MyString
+  description: MyText

test/graphql/mutations/create_link_test.rb

@@ -0,0 +1,18 @@
+require 'test_helper'
+
+class Mutations::CreateLinkTest < ActiveSupport::TestCase
+  def perform(user: nil, **args)
+    Mutations::CreateLink.new(object: nil, context: {}).resolve(args)
+  end
+
+  test 'create a new link' do
+    link = perform(
+      url: 'http://example.com',
+      description: 'description',
+    )
+
+    assert link.persisted?
+    assert_equal link.description, 'description'
+    assert_equal link.url, 'http://example.com'
+  end
+end

test/models/link_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class LinkTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end