ruby-on-rails – 使用Rspec测试无效的电子邮件

describe "when email format is invalid" do
    it "should be invalid" do
      addresses = %w[user@foo,com user_at_foo.org example.user@foo.
                     foo@bar_baz.com foo@bar+baz.com]
      addresses.each do |invalid_address|
        @user.email = invalid_address
        @user.should_not be_valid
      end      
    end

我是Rspec的初学者.以前,有一个这样的代码：

describe "when email is not present" do
    before { @user.email = " " }
    it { should_not be_valid }
  end

所以我想知道为什么作者没有像这样编写上面的代码：

describe "when email format is invalid" do
    before do
      addresses = %w[user@foo,com user_at_foo.org example.user@foo.
                     foo@bar_baz.com foo@bar+baz.com]
      @user.email = invalid_address 
      addresses.each do |invalid_address|
        @user.email = invalid_address
      end 
    end

    it { should_not be_valid }          
 end

好吧,也许这段代码错了.但基本上,我问的是为什么作者之前没有使用它或者在它之前放置地址变量？ (正如他在前一个例子中所做的那样)

编辑：

他还在另一个例子中做了类似的事情：

describe "when email address is already taken" do
    before do
      user_with_same_email = @user.dup
      user_with_same_email.email = @user.email.upcase
      user_with_same_email.save
    end

    it { should_not be_valid }
  end