Add grape controller module with test application

Appraisals

@@ -1,5 +1,20 @@
 appraise 'rails-app' do
   gem 'rails', '6.0.3.1'
   gem 'sqlite3', '~> 1.4'
-  gem "trailblazer-operation"
+  gem "representable"
+  gem "trailblazer-operation", '>= 0.6.5'
+  gem "trailblazer-cells"
+  gem "cells-rails"
+  gem "cells-erb"
+  gem "jwt"
+end
+
+appraise 'grape-app' do
+  gem 'grape', '~> 1.5'
+  gem "zeitwerk", "~> 2.4"
+  gem "representable"
+  gem "trailblazer-operation", '>= 0.6.5'
+
+  gem "minitest-line", "~> 0.6"
+  gem "rack-test", "1.1.0"
 end

Rakefile

@@ -9,8 +9,18 @@ Rake::TestTask.new(:test) do |test|
   test.verbose = true
 end
 
+# To run grape app's test, run below command
+# $ appraisal rails-app rake test-rails-app
 Rake::TestTask.new('test-rails-app') do |test|
   test.libs << 'test'
   test.test_files = FileList['test/rails-app/test/test_helper.rb', 'test/rails-app/test/**/*.rb']
   test.verbose = true
 end
+
+# To run grape app's test, run below command
+# $ appraisal grape-app rake test-grape-app
+Rake::TestTask.new('test-grape-app') do |test|
+  test.libs << 'test'
+  test.test_files = FileList['test/grape-app/test/test_helper.rb', 'test/grape-app/test/**/*.rb']
+  test.verbose = true
+end

gemfiles/grape_app.gemfile

@@ -0,0 +1,14 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "multi_json"
+gem "minitest-line", "~> 0.6"
+gem "dry-validation"
+gem "grape", "~> 1.5"
+gem "zeitwerk", "~> 2.4"
+gem "representable"
+gem "trailblazer-operation", ">= 0.6.5"
+gem "rack-test", "1.1.0"
+
+gemspec path: "../"

gemfiles/rails_app.gemfile

@@ -0,0 +1,17 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "multi_json"
+gem "minitest-line"
+gem "dry-validation"
+gem "rails", "6.0.3.1"
+gem "sqlite3", "~> 1.4"
+gem "representable"
+gem "trailblazer-operation", ">= 0.6.5"
+gem "trailblazer-cells"
+gem "cells-rails"
+gem "cells-erb"
+gem "jwt"
+
+gemspec path: "../"

lib/trailblazer/endpoint/controller.rb

@@ -124,8 +124,12 @@ def build_endpoint(name, domain_activity: name, **options)
       end
 
       module InstanceMethods
+        # Returns object link between compile-time and run-time config
+        def config_source
+          self.class
+        end
 
-        def endpoint_for(name, config_source: self.class)
+        def endpoint_for(name)
           config_source.options_for(:endpoints, {}).fetch(name.to_s) # TODO: test non-existant endpoint
         end
 
@@ -144,9 +148,8 @@ def invoke_endpoint_with_dsl(options, &block)
         end
 
         module API
-          def endpoint(name, config_source: self.class, **action_options)
-            endpoint = endpoint_for(name, config_source: config_source)
-
+          def endpoint(name, **action_options)
+            endpoint = endpoint_for(name)
             action_options = {controller: self}.merge(action_options) # FIXME: redundant with {InstanceMethods#endpoint}
 
             block_options = config_source.options_for(:options_for_block_options, **action_options)

lib/trailblazer/endpoint/grape/controller.rb

@@ -0,0 +1,28 @@
+module Trailblazer
+  class Endpoint
+    # Grape Integration
+    #
+    module Grape
+      module Controller
+        # Make endpoint's compile time methods available in `base` and
+        # instance methods available in it's routes.
+        def self.included(base)
+          base.extend(Trailblazer::Endpoint::Controller)
+
+          base.helpers(
+            Trailblazer::Endpoint::Controller::InstanceMethods,
+            Trailblazer::Endpoint::Controller::InstanceMethods::API
+          )
+
+          base.helpers do
+            # Override `Controller::InstanceMethods#config_source` to return `base`
+            # as the link between compile-time and run-time config.
+            #
+            # @api public
+            define_method(:config_source, ->{ base })
+          end
+        end
+      end
+    end
+  end
+end

test/grape-app/app/api/app.rb

@@ -0,0 +1,5 @@
+module App
+  class API < Grape::API
+    mount V1::API => "/v1"
+  end
+end

test/grape-app/app/api/v1.rb

@@ -0,0 +1,6 @@
+module V1
+  class API < Grape::API
+    format :json
+    mount V1::Album => "/albums"
+  end
+end

test/grape-app/app/api/v1/album.rb

@@ -0,0 +1,67 @@
+module V1
+  class Album < V1::API
+    include Trailblazer::Endpoint::Grape::Controller
+
+    def self.options_for_endpoint(ctx, controller:, **) 
+      {   
+        request: controller.request,
+        errors: Trailblazer::Endpoint::Adapter::API::Errors.new,
+      }
+    end
+
+    def self.options_for_domain_ctx(ctx, controller:, **)
+      {   
+        params: controller.params,
+        # current_user: current_user,  # TODO: Access current_user
+      }
+    end 
+
+    def self.options_for_block_options(ctx, controller:, **)
+      response_block = ->(ctx, endpoint_ctx:, **) do
+        controller.body json: ctx[:model]
+        controller.status endpoint_ctx[:status]
+      end
+
+      failure_block = ->(ctx, endpoint_ctx:, **) do
+        controller.body json: ctx[:errors].message
+        controller.status endpoint_ctx[:status]
+      end
+
+      {
+        success_block:          response_block,
+        failure_block:          failure_block,
+        protocol_failure_block: failure_block
+      }
+    end
+
+    directive :options_for_endpoint,      method(:options_for_endpoint)
+    directive :options_for_domain_ctx,    method(:options_for_domain_ctx)
+    directive :options_for_block_options, method(:options_for_block_options)
+
+    endpoint ::Album::Operation::Index, protocol: Application::Endpoint::Protocol, adapter: Application::Endpoint::Adapter
+    desc "Get list of albums"
+    get { endpoint ::Album::Operation::Index, representer_class: ::Album::Representer }
+
+    endpoint ::Song::Operation::Index, protocol: Application::Endpoint::Protocol, adapter: Application::Endpoint::Adapter
+    endpoint ::Song::Operation::Create, protocol: Application::Endpoint::Protocol, adapter: Application::Endpoint::Adapter
+
+    # FIXME: Use inheritance same as Rails's ApplicationController for maintaining global config
+    # Grape has anonymous class scope within resource block which doesn't copy inheritance settings
+    # mount ::V1::Song => ':album_id/songs'
+
+    resource ':album_id/songs' do
+      desc "Get list of songs"
+      get { endpoint ::Song::Operation::Index, representer_class: ::Song::Representer }
+
+      desc "Create a song"
+      post do
+        on_create = ->(ctx, model:, endpoint_ctx:, **) do
+          status 201
+          body json: endpoint_ctx[:representer_class].new(model).to_json
+        end
+
+        endpoint ::Song::Operation::Create, success_block: on_create, representer_class: ::Song::Representer
+      end
+    end
+  end
+end

test/grape-app/app/concepts/album/operation/index.rb

@@ -0,0 +1,7 @@
+class Album::Operation::Index < Trailblazer::Operation
+  step :model
+
+  def model(ctx, **)
+    ctx[:model] = 3.times.collect{ |i| Album.new(i) }
+  end
+end

test/grape-app/app/concepts/album/representer.rb

@@ -0,0 +1,7 @@
+require 'representable'
+
+class Album::Representer < Representable::Decorator
+  include Representable::JSON
+
+  property :id
+end

test/grape-app/app/concepts/application/endpoint/adapter.rb

@@ -0,0 +1,6 @@
+module Application::Endpoint
+  class Adapter < Trailblazer::Endpoint::Adapter::API
+    include Errors::Handlers
+    insert_error_handler_steps!(self)
+  end
+end

test/grape-app/app/concepts/application/endpoint/protocol.rb

@@ -0,0 +1,14 @@
+module Application::Endpoint
+  class Protocol < Trailblazer::Endpoint::Protocol
+    def authenticate(ctx, controller:, **)
+      username, password = Rack::Auth::Basic::Request.new(controller.env).credentials
+      return false if username != password
+
+      ctx[:current_user] = User.new(username)
+    end
+
+    def policy(ctx, current_user:, **)
+      current_user.username == 'admin'
+    end
+  end
+end

test/grape-app/app/concepts/song/operation/create.rb

@@ -0,0 +1,7 @@
+class Song::Operation::Create < Trailblazer::Operation
+  step :model
+
+  def model(ctx, params:, **)
+    ctx[:model] = Song.new(1, params.fetch(:album_id), "current_user.username") # TODO: Access current_user
+  end
+end

test/grape-app/app/concepts/song/operation/index.rb

@@ -0,0 +1,7 @@
+class Song::Operation::Index < Trailblazer::Operation
+  step :model
+
+  def model(ctx, **)
+    ctx[:model] = 3.times.collect{ |i| Song.new(i) }
+  end
+end

test/grape-app/app/concepts/song/representer.rb

@@ -0,0 +1,9 @@
+require 'representable'
+
+class Song::Representer < Representable::Decorator
+  include Representable::JSON
+
+  property :id
+  property :album_id
+  property :created_by
+end

test/grape-app/app/models/album.rb

@@ -0,0 +1,2 @@
+class Album < Struct.new(:id)
+end

test/grape-app/app/models/song.rb

@@ -0,0 +1,2 @@
+class Song < Struct.new(:id, :album_id, :created_by)
+end

test/grape-app/app/models/user.rb

@@ -0,0 +1,2 @@
+class User < Struct.new(:username)
+end

test/grape-app/config.ru

@@ -0,0 +1,15 @@
+require "grape"
+require "zeitwerk"
+
+require "trailblazer/operation"
+require "trailblazer/endpoint"
+require "trailblazer/endpoint/grape/controller"
+
+loader = Zeitwerk::Loader.new
+loader.push_dir("#{__dir__}/app/api")
+loader.push_dir("#{__dir__}/app/models")
+loader.push_dir("#{__dir__}/app/concepts")
+loader.setup
+
+App::API.compile!
+run App::API

test/grape-app/test/album_api_test.rb

@@ -0,0 +1,37 @@
+require "test_helper"
+
+class AlbumApiTest < Minitest::Spec
+  include Rack::Test::Methods
+
+  def app
+    APP_API
+  end
+
+  it "not_authenticated" do
+    get "/v1/albums", {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'wrong')
+
+    assert_equal last_response.status, 401
+    assert_equal last_response.body, "{\"json\":\"Authentication credentials were not provided or are invalid.\"}"
+  end
+
+  it "not_authorized" do
+    get "/v1/albums", {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('not_admin', 'not_admin')
+
+    assert_equal last_response.status, 403
+    assert_equal last_response.body, "{\"json\":\"Action not allowed due to a policy setting.\"}"
+  end
+
+  it "success" do
+    get "/v1/albums", {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'admin')
+
+    assert_equal last_response.status, 200
+    # assert_equal last_response.body, "" # TODO: Use representer
+  end
+
+  it "created" do
+    post "/v1/albums/1/songs", {}, 'HTTP_AUTHORIZATION' => encode_basic_auth('admin', 'admin')
+
+    assert_equal last_response.status, 201
+    assert_equal JSON.parse(last_response.body), {"json"=>"{\"id\":1,\"album_id\":\"1\",\"created_by\":\"current_user.username\"}"}
+  end
+end

test/grape-app/test/test_helper.rb

@@ -0,0 +1,11 @@
+require "minitest/autorun"
+require "rack/test"
+
+config_path = File.expand_path(File.join(__FILE__, '../../config.ru'))
+APP_API = Rack::Builder.parse_file(config_path).first
+
+Minitest::Spec.class_eval do
+  def encode_basic_auth(username, password)
+    'Basic ' + Base64.encode64("#{username}:#{password}")
+  end
+end

trailblazer-endpoint.gemspec

@@ -23,4 +23,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake"
   spec.add_development_dependency "minitest"
   spec.add_development_dependency "trailblazer-developer"
+  spec.add_development_dependency "appraisal"
 end