关于Ruby / ChefSpec编码风格的反馈

Question

我对Ruby比较陌生，但在过去的两周里，我已经做了很多关于Chef测试的研究。这个测试使用了ChefSpec & Fauxhai，但它看起来不是很“红宝石”，我希望社区能给我一些关于编码风格的建议。有没有更好的方法来编写像这样的嵌套循环？

cookbooks/foo/recipes/default.rb

package "foo" do
  action :install
end

cookbooks/foo/spec/default_spec.rb

require 'chefspec'

describe 'foo::default' do
  platforms = { 
    "debian"   => ['6.0.5'],
    "ubuntu"   => ['12.04', '10.04'],
    "centos"   => ['5.8', '6.0', '6.3'],
    "redhat"   => ['5.8', '6.3'],
    "mac_os_x" => ['10.6.8', '10.7.4', '10.8.2'],
    "windows"  => ['2008R2']
  }

  platforms.each do |platform,versions|
    versions.each do |version|
      context "on #{platform} #{version}" do
        before do
          Fauxhai.mock(platform: platform, version: version)
        end

        it 'should install foo' do
          @runner = ChefSpec::ChefRunner.new.converge('foo::default')
          @runner.should install_package 'foo'
        end
      end
    end
  end
end

欢迎任何和所有的反馈。谢谢!

Answer 1

首先，一种常见的做法是将ChefRunner实例化提取到let助手中。您还可以在其中包含所有Fauxhai配置：

let(:chef_run) do
  ChefSpec::ChefRunner.new(platform: platform, version: version) do |node|
    node.set['foo']['bar'] = 'baz'
    # ....
  end.converge('foo::default')
end

it "installs foo" do
  expect(chef_run).to install_package 'foo'
end

expect语法似乎是recommended over should。但在本例中，我将使用一行代码：

subject do
  ChefSpec::ChefRunner.new(platform: platform, version: version).converge('foo::default')
end
it { should install_package 'foo' }

要清理一下循环，可以使用RSpec's shared examples。一个更广泛的例子：

require 'chefspec'

shared_examples 'foo' do |platform, version|
  context "on #{platform} #{version}" do
    let(:users) { %w[user1 user2] }
    let(:chef_run) do
      ChefSpec::ChefRunner.new(platform: platform, version: version) do |node|
        node.set['foo']['users'] = users
      end.converge('foo::default')
    end
    subject { chef_run }

    it { should install_package 'foo' }

    it "creates specified users" do
      users.each { |u| expect(chef_run).to create_user u }
    end
  end
end

describe 'foo::default' do
  platforms = {
    'debian'   => ['6.0.5'],
    'ubuntu'   => ['12.04', '10.04'],
    'centos'   => ['5.8', '6.0', '6.3'],
    'redhat'   => ['5.8', '6.3'],
    'mac_os_x' => ['10.6.8', '10.7.4', '10.8.2'],
    'windows'  => ['2008R2']
  }

  platforms.each do |platform, versions|
    versions.each do |version|
      include_examples 'foo', platform, version
    end
  end
end