ruby – 如何使用rspec测试CLI的stdin

我正在制作一个小型的 Ruby程序,无法弄清楚如何编写模拟多个用户命令行输入的RSpec规范(功能本身可行).我认为 this StackOverflow answer可能涵盖了离我最近的地方,但这并不是我需要的.我使用 Thor作为命令行界面,但我不认为这是Thor的任何问题.

程序可以从文件或命令行读取命令,并且我已经能够成功编写测试以读取执行它们.这是一些代码：

cli.rb

class CLI < Thor
  # ...
  method_option :filename,aliases: ['-f'],desc: "name of the file containing instructions",banner: 'FILE'

  desc "execute commands","takes actions as per commands"
  def execute
    thing = Thing.new
    instruction_set do |instructions|
      instructions.each do |instruction|
        command,args = parse_instruction(instruction) # private helper method
        if valid_command?(command,args) # private helper method
          response = thing.send(command,*args)
          puts format(response) if response
        end
      end
    end
  end

  # ...

  no_tasks do
    def instruction_set
      if options[:filename]
        yield File.readlines(options[:filename]).map { |a| a.chomp }
      else
        puts usage
        print "> "
        while line = gets
          break if line =~ /EXIT/i
          yield [line]
          print "> "
        end
      end
    end
    # ..
  end

我已经成功测试了使用以下代码执行文件中包含的命令：

投机/ cli_spec.rb

describe CLI do

  let(:cli) { CLI.new }

  subject { cli }

  describe "executing instructions from a file" do
    let(:default_file) { "instructions.txt" }
    let(:output) { capture(:stdout) { cli.execute } }

    context "containing valid test data" do
      valid_test_data.each do |data|
        expected_output = data[:output]

        it "should parse the file contents and output a result" do
          cli.stub(:options) { { filename: default_file } } # Thor options hash
          File.stub(:readlines).with(default_file) do
            StringIO.new(data[:input]).map { |a| a.strip.chomp }
          end
          output.should == expected_output
        end
      end
    end
  end
  # ...
end

并且上面提到的valid_test_data采用以下形式：

支持/ utilities.rb

def valid_test_data
  [
    {
      input: "C1 ARGSr
              C2r
              C3r
              C4",output: "OUTPUTn"
    }
    # ...
  ]
end

我现在要做的是完全相同的事情,但不是从’文件’中读取每个命令并执行它,我想以某种方式模拟用户输入到标准输入.下面的代码是完全错误的,但我希望它可以传达我想要的方向.

投机/ cli_spec.rb

# ...
# !!This code is wrong and doesn't work and needs rewriting!!
describe "executing instructions from the command line" do
  let(:output) { capture(:stdout) { cli.execute } }

  context "with valid commands" do
    valid_test_data.each do |data|
      let(:expected_output) { data[:output] }
      let(:commands) { StringIO.new(data[:input]).map { |a| a.strip } }

      it "should process the commands and output the results" do
        commands.each do |command|
          cli.stub!(:gets) { command }
          if command == :report
            STDOUT.should_receive(:puts).with(expected_output)
          else
            STDOUT.should_receive(:puts).with("> ")
          end
        end
        output.should include(expected_output)
      end
    end
  end
end

我尝试在各个地方使用cli.stub(：puts),并且通常重新安排这些代码,但似乎无法获取我的任何存根来将数据放入stdin.我不知道我是否可以像命令文件一样解析命令行所期望的输入集,或者我应该用什么代码结构来解决这个问题.如果指定了命令行应用程序的人可以插入,那就太棒了.谢谢.

class CLI < Thor
  def initialize(stdout=STDOUT)
    @stdout = stdout
  end

  # ...

  @stdout.puts # instead of raw puts
end

let(:stdout) { StringIO.new }
let(:cli) { CLI.new(stdout) }