TDA.rb

class Book
  attr_reader :name, :author, :year

  def initialize(name, author, year)
    @name = name
    @author = author
    @year = year
  end

  def full_description
    "Name: #{name}, Author: #{author}, Year: #{year}"
  end
end

class Stock
  attr_reader :quantity, :maximum_quantity
  attr_accessor :books

  def initialize(books: [], quantity: 0, maximum_quantity: 10)
    @books = books
    @quantity = quantity
    @maximum_quantity = maximum_quantity
  end

  def <<(book)
    books << book unless crowded
  end

  def crowded
    quantity == maximum_quantity
  end

  def print_books
    books.each do |book|
      puts book.full_description
    end
  end
end

book1 = Book.new("Practical Object-Oriented Design in Ruby","Sandi Metz","2012")
book2 = Book.new("Ruby Under a Microscope","Pat Shaughnessy","2013")

stock = Stock.new

stock << book1
stock << book2

stock.print_books