rspec 中的模拟方法链

使用 RSpec 中的模拟方法链来编写更强大的测试代码

ruby
class Order
  attr_reader :user, :product
  def initialize(user, product)
    @user = user
    @product = product
  end
  def calculate_total_price
    user_discount = user.discount
    product_price = product.price
    total_price = product_price * (1 - user_discount)
    total_price
  end
end
class User
  def discount
    0.1
  end
end
class Product
  def price
    100
  end
end
RSpec.describe Order do
  it "calculates the total price correctly" do
    user = User.new
    product = Product.new
    order = Order.new(user, product)
    allow(user).to receive(:discount).and_return(0.2)
    allow(product).to receive(:price).and_return(50)
    total_price = order.calculate_total_price
    expect(total_price).to eq(40)
  end
end