clupprich · March 15, 2021 08:39 · Mar 15, 2021
diff --git a/railsfile_books.rb b/railsfile_books.rb
@@ -0,0 +1,103 @@
+require "bundler/inline"
+
+gemfile(true) do
+  source "https://rubygems.org"
+
+  gem "rails"
+  gem "pg"
+end
+
+require "active_record"
+require "action_controller/railtie"
+
+ActiveRecord::Base.establish_connection(adapter: "postgresql", database: "railstestdb")
+ActiveRecord::Base.logger = Logger.new(STDOUT)
+
+ActiveRecord::Schema.define do
+  create_table :books, force: true do |t|
+    t.string :name
+    t.timestamps
+  end
+
+  create_table :users, force: true do |t|
+    t.string :name
+    t.timestamps
+  end
+
+  create_table :readings, force: true do |t|
+    t.references :book
+    t.references :user
+    t.timestamps
+  end
+end
+
+class Book < ActiveRecord::Base
+  has_many :readings
+  has_many :users, through: :readings
+
+  def self.read_by(*users)
+    includes(:readings).where(readings: { user_id: users })
+  end
+end
+
+class User < ActiveRecord::Base
+  has_many :readings
+  has_many :books, through: :readings
+end
+
+class Reading < ActiveRecord::Base
+  belongs_to :book
+  belongs_to :user
+end
+
+class LibraryApp < Rails::Application
+  secrets.secret_token    = "secret_token"
+  secrets.secret_key_base = "secret_key_base"
+
+  config.logger = Logger.new($stdout)
+  Rails.logger = config.logger
+
+  routes.draw do
+    resources :books, only: [:index]
+  end
+end
+
+class BooksController < ActionController::Base
+  def index
+    @books = Book.all
+    render json: @books
+  end
+end
+
+require "minitest"
+
+class BookTest < Minitest::Test
+  def test_read_by
+    book1 = Book.create!(name: 'Generation X')
+    book2 = Book.create!(name: 'Microserfs')
+    book3 = Book.create!(name: 'American Polaroids')
+
+    user1 = User.create!(name: 'Daniel')
+    user2 = User.create!(name: 'Susan')
+    user3 = User.create!(name: 'Todd')
+
+    Reading.create!(book: book1, user: user1)
+    Reading.create!(book: book2, user: user2)
+    Reading.create!(book: book2, user: user3)
+
+    books = Book.read_by(user2)
+    assert_equal books, [book2, book3]
+  end
+end
+
+exit_code = Minitest.run
+exit exit_code unless exit_code
+
+require "rails/command"
+require "rails/commands/server/server_command"
+
+options = {
+  app: LibraryApp,
+  Host: '0.0.0.0'
+}
+Rails::Server.new(options).start
No results found