ruby-on-rails - 类已泄漏到另一个示例中，不能再在规范中使用

Question

我无法在本地复制它，但出于某种原因，我在 CircleCi 中运行测试时遇到以下错误:

<Double Mylogger> was originally created in one example but has leaked into another example and can no longer be used. rspec-mocks' doubles are designed to only last for one example, and you need to create a new one in each example you wish to use it for.

这是我的代码的简化版本:

# frozen_string_literal: true
describe 'my_rake_task' do
  let(:my_log) { Mylogger.new }

  subject { Rake::Task['my_rake_task'].execute }

  describe 'one' do
    context 'logs' do
      let(:logs) do
        [
          ['My message one'],
          ['My message two'],
        ]
      end

      after { subject }

      it 'correctly' do
        logs.each { |log| expect(my_log).to receive(:info).with(*log) }
      end
    end
  end

  describe 'two' do
    context 'logs' do
      let(:logs) do
        [
          ['My message three'],
          ['My message four'],
        ]
      end

      after { subject }

      it 'correctly' do
        logs.each { |log| expect(my_log).to receive(:info).with(*log) }
      end
    end
  end
end

为什么说 MyLogger 是双重的？为什么会漏水？

Answer 1

错误说 MyLogger 是 double 的原因是因为它是一个。当您调用 expect(my_log).to receive 或 allow(my_log).to receive 时，您将实例转换为 partial-double。 .

至于为什么 my_log 泄漏:从您发布的代码中无法判断。为了造成泄漏，您的 rake 任务或规范本身中的某些代码需要将 my_log 注入(inject)某个全局状态，like a class variable .