使用RSpec在断言中的期望块内创建的对象

Question

我正在尝试编写一个测试，在该测试中我需要由期望的块创建的值来编写断言。

class Identification < ApplicationRecord
  include Wisper::Publisher

  after_save :publish_identification_declined

  private

  def publish_identification_declined
    if status_previously_changed? && status == "declined"
      broadcast(:identification_declined, identification: self)
    end
  end
end

我试图做这样的事情，但不幸的是identification_a最终没有被设置。

require "rails_helper"

RSpec.describe Identification do
  it "publish event identification_declined" do
    identification_a = nil
    expect { identification_a = create(:identification, :declined, id: 1) }
      .to broadcast(:identification_declined, identification: identification_a)
  end
end

我也觉得这可能不是一个好主意。

一种替代方法可能是使用instance_of匹配器，但是我不知道如何检查它是否是正确的实例。

Answer 1

我认为您不应该测试私有函数，因为它们就像黑匣子一样，无论它如何工作，只要它按预期返回，就需要花费很多时间，但在那种情况下，我认为该函数不应该处于私有状态。

如果要测试是否调用了该函数，则可以使用receive rspec函数。像：

require "rails_helper"

RSpec.describe Identification do
  subject { described_class.new(identification: nil, :declined, id: 1) }

  it "updates the state after save(or the event that should runs)" do
    expect { subject }.to receive(:publish_identification_declined)
    subject.save
  end
end

您也可以看到the documentation