如何在最低测试中存入兰特? [英] How can I stub rand in minitest?

问题描述

我尝试了Random.stub :rand, 1 do ... end和Kernel.stub :rand, 1 do ... end和Class.stub :rand, 1 do ... end(因为当我在运行rand(2)的地方运行rand(2)时，我得到了Class).我也尝试过用Random.rand(2)替换rand(2)，但这没有帮助.

I've tried Random.stub :rand, 1 do ... end and Kernel.stub :rand, 1 do ... end and Class.stub :rand, 1 do ... end (because when I run self.class where I run rand(2) I get Class). I've also tried replacing rand(2) with Random.rand(2) but it doesn't help.

那我该如何对兰特进行存根处理?

So how do I stub out rand?

推荐答案

rand是Kernel模块的一部分，该模块混入每个类中.要对其进行存根处理，您需要在调用rand的对象上调用stub.

rand is part of the Kernel module that is mixed into every class. To stub it, you need to call stub on the object where rand is being called.

在一个示例中可能最容易看到.在下面的代码中，rand是Coin的私有实例方法，因为Coin隐式继承自Object和Kernel.因此，我需要在Coin的 instance 上存根.

It's probably easiest to see in an example. In the following code, rand is a private instance method of the Coin, because Coin implicitly inherits from Object and Kernel. Therefore I need to stub on the instance of Coin.

require "minitest/autorun"
require "minitest/mock"

class Coin
  def flip
    rand(0..1) == 1 ? "heads" : "tails"
  end
end

class CoinTest < Minitest::Test
  def test_flip
    coin = Coin.new
    coin.stub(:rand, 0) do
      assert_equal("tails", coin.flip)
    end
  end
end

这篇关于如何在最低测试中存入兰特?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！