ruby - rspec newb 不明白如何满足“之前”方法

Question

新手在这里...刚刚开始使用 rspec 并有以下问题：

describe Song do

  before do
     @song = Song.new
  end

  describe 'title' do
    it 'should capitalize the first letter' do
      @song.title = "lucky"
      @song.title.should == "Lucky"
    end
end

我不确定如何满足“before do ....end”我看到它被写在许多教程和 rspec 示例中，但我仍然不知道如何满足 ruby​​ 代码以便它通过。谢谢

Answer 1

RSpec 一开始可能会让人感到困惑，因为总是有许多有效的方法可以实现相同的目标。这就是为什么我建议您获取The Rspec Book而不是（或之前）通过“许多教程和示例”。

对于这个单一的测试，我可以很容易地想出八种不同的方法（参见下面的代码示例），你可以更多地混合和匹配它们的一部分，从而产生更多不同的方法来解决相同的问题。

这就是为什么我认为在您能够通过示例和教程工作之前对 RSpec 原则有基本的了解是必要的——每个示例看起来都会略有不同，但是如果您掌握了基础知识，您将很容易能够看到每个示例的内容做。

require "rspec"

class Song
  def title=(title)
    @title = title
  end

  def title
    @title.capitalize
  end
end

describe Song do
  before { @song = Song.new }

  describe "#title" do
    it "should capitalize the first letter" do
      @song.title = "lucky"
      @song.title.should == "Lucky"
    end
  end
end

describe Song do
  describe "#title" do
    it "should capitalize the first letter" do
      song = Song.new
      song.title = "lucky"
      song.title.should == "Lucky"
    end
  end
end

describe Song do
  let(:song) { Song.new }

  describe "#title" do
    before { song.title = "lucky" }

    it "should capitalize the first letter" do
      song.title.should == "Lucky"
    end
  end
end

describe Song do
  let(:song)  { Song.new }
  subject     { song }

  before { song.title = "lucky" }

  its(:title) { should == "Lucky" }
end

describe Song do
  let(:song) { Song.new }

  describe "#title" do
    before { song.title = "lucky" }

    context "capitalization of the first letter" do
      subject { song.title }
      it { should == "Lucky" }
    end
  end
end

describe Song do
  context "#title" do
    before { subject.title = "lucky" }
    its(:title) { should == "Lucky" }
  end
end

RSpec::Matchers.define :be_capitalized do
  match do |actual|
    actual.capitalize == actual
  end
end

describe Song do
  context "#title" do
    before { subject.title = "lucky" }
    its(:title) { should be_capitalized }
  end
end

describe Song do
  let(:song) { Song.new }

  context "#title" do
    subject { song.title }
    before { song.title = "lucky" }
    it { should be_capitalized }
  end
end