使用和不使用Rails的快速(Rspec)测试

Question

我有两节课:

1.Sale是ActiveRecord的子类; 它的工作是将销售数据保存到数据库中.

class Sale < ActiveRecord::Base
  def self.total_for_duration(start_date, end_date)
    self.count(conditions: {date: start_date..end_date})
  end
  #...
end

2.SalesReport是一个标准的Ruby类; 它的工作是生成和绘制有关销售的信息.

class SalesReport
  def initialize(start_date, end_date)
    @start_date = start_date
    @end_date = end_date
  end

  def sales_in_duration
    Sale.total_for_duration(@start_date, @end_date)
  end
  #...
end

因为我想使用TDD并且我希望我的测试运行得非常快,所以我为SalesReport编写了一个不加载Rails的规范:

require_relative "../../app/models/sales_report.rb"

class Sale; end
# NOTE I have had to re-define Sale because I don't want to
# require `sale.rb` because it would then require ActiveRecord.

describe SalesReport do
  describe "sales_in_duration" do
    it "calls Sale.total_for_duration" do
      Sale.should_receive(:total_for_duration)
      SalesReport.new.sales_in_duration
    end
  end
end

运行时,此测试有效bundle exec rspec spec/models/report_spec.rb.

但是,当我运行bundle exec rake spec错误时,此测试失败superclass mismatch for class Sale (TypeError).我知道错误正在发生,因为Tap是由sale.rb规范中的内联定义的.

所以我的问题是,如果没有定义该类,有一种方法可以将Stub(或Mock或Double)作为一个类吗？ 这将允许我删除内联class Sale; end,这感觉就像一个黑客.

如果没有,我如何设置我的测试,使他们无论我跑bundle exec rspec还是正常运行bundle exec rake spec？

如果没有,我写快速测试的方法是错误的吗？!

最后,我不想使用Spork.谢谢!

Answer 1

最近添加的 RSpecstub_const是专门为以下情况而设计的：

describe SalesReport do
  before { stub_const("Sale", Class.new) }

  describe "sales_in_duration" do
    it "calls Sale.total_for_duration" do
      Sale.should_receive(:total_for_duration)
      SalesReport.new.sales_in_duration
    end
  end
end

您可能还想使用rspec-fire来使用测试替身来代替在加载真实类的情况下运行测试时（例如，当您运行测试套件时）Sale自动检查真实类上存在的所有模拟/存根方法：SaleSale

require 'rspec/fire'

describe SalesReport do
  include RSpec::Fire

  describe "sales_in_duration" do
    it "calls Sale.total_for_duration" do
      fire_replaced_class_double("Sale")
      Sale.should_receive(:total_for_duration)
      SalesReport.new.sales_in_duration
    end
  end
end

如果您total_for_duration在真实Sale类上重命名，则当您模拟该方法时，rspec-fire 会给您一个错误，因为它在真实类上不存在。