在RSpec中捕获STDOUT

Question

我是Ruby的单元测试的新手,我在创建一个检查STDOUT的规范时遇到了一些麻烦.我知道如果我正在测试的代码是在类/方法中,如何测试STDOUT,但我想测试puts来自不在Class或Method中的常规Ruby文件的语句.

这是一个简单的一个班轮 my_file.rb

puts "Welcome to the Book Club!"

这是规格

my_spec.rb

require_relative 'my_file.rb'

  describe "Something I'm Testing" do
    it 'should print Welcome to the Book Club!' do

        expect {$stdout}.to output("Welcome to the Book Club!\n").to_stdout

      end
    end

我收到以下错误消息:

Failures:

  1) Something I'm Testing should print Welcome to the Book Club!
     Failure/Error: expect {$stdout}.to output("Welcome to the Book Club!\n").to_stdout

       expected block to output "Welcome to the Book Club!\n" to stdout, but output nothing
       Diff:
       @@ -1,2 +1 @@
       -Welcome to the Book Club!
       # ./spec/my_spec.rb:9:in `block (2 levels) in <top (required)>'

Finished in 0.01663 seconds (files took 0.08195 seconds to load)
1 example, 1 failure

Failed examples:

rspec ./spec/my_spec.rb:7 # Something I'm Testing should print Welcome to the Book Club!

我以为我可以$stdout用来捕获STDOUT,my_file.rb但是没有用.输出一直没有说.我发现这篇文章讲述了通过Rspec中的测试STDOUT输出捕获输出StringIO

但这种方法对我不起作用.我究竟做错了什么？

谢谢!

Answer 1

在测试运行之前puts将my_file.rb权限包含在顶部时,将调用您的方法.将其包含在您的测试中.

describe "Something I'm Testing" do
  it 'should print Welcome to the Book Club!' do
     expect { require_relative 'my_file.rb' }.to output("Welcome to the Book Club!\n").to_stdout
  end
end