capybara 2.0+ 中的嵌套功能

Question

我想做这样的事情：

feature "sign-up" do
  before {visit signup_path}
  let(:submit) {"Create my account"}

  feature "with invalid information" do
    scenario "should not create a user" do
      expect {click_button submit}.not_to change(User, :count)
    end
  end

  feature "with valid information" do
    scenario "should create a user" do
      fill_in "Name",         with: "test name"
      fill_in "Email",        with: "test@test.com"
      fill_in "Password",     with: "password"
      fill_in "Confirmation", with: "password"
      expect {click_button submit}.to change(User, :count).by(1)
    end
  end
end

但是当我运行 rspec 我得到了

in `block in <top (required)>': undefined method `feature' for #<Class:0x000000039e0018> (NoMethodError)

如果我稍微改变一下它看起来像这样它可以工作：

  feature "with invalid information" do
    before {visit signup_path}
    let(:submit) {"Create my account"}

    scenario "should not create a user" do
      expect {click_button submit}.not_to change(User, :count)
    end
  end

  feature "with valid information" do
    before {visit signup_path}
    let(:submit) {"Create my account"}

    scenario "should create a user" do
      fill_in "Name",         with: "test name"
      fill_in "Email",        with: "test@test.com"
      fill_in "Password",     with: "nirnir"
      fill_in "Confirmation", with: "nirnir"
      expect {click_button submit}.to change(User, :count).by(1)
    end
  end

编辑：

另外，下面的代码可以工作（描述嵌套的内部特性）——但它有什么错误吗？

feature "sign-up" do
  background {visit signup_path}
  given(:submit) {"Create my account"}

  scenario "with invalid information" do
    expect {click_button submit}.not_to change(User, :count)
  end

  describe "with valid information" do
    background do
      fill_in "Name",         with: "test name"
      fill_in "Email",        with: "test@test.com"
      fill_in "Password",     with: "password"
      fill_in "Confirmation", with: "password"
    end

    scenario { expect {click_button submit}.to change(User, :count).by(1) }

    scenario "after submission" do 
      click_button submit
      page.html.should have_content("Registration successful")
    end
  end
end

Answer 1

编辑（23/01/2014）：嵌套功能从 2.2.1 版开始可用。见here

编辑（2013 年 7 月 24 日）： Capybara > 2.1.0 将允许嵌套功能。见here

你不能。宝石管理员是这么说的

我想你可以称之为限制。 feature 不能嵌套。 您可以改用context 或describe，但我会 建议不要对这些疯狂，它往往会使测试变得漂亮 不可读。

在某些其他情况下，可能会争论这样做的便利性，但在这个特定的情况下，您应该使用 scenario 而不是嵌套的 feature。

此外，如果您想在任何地方保持一致并使用新的 DSL，请使用 background 而不是 before 和 given 而不是 let。像这样：

feature "sign-up" do
  background {visit signup_path}
  given(:submit) {"Create my account"}

  scenario "with invalid information" do
    expect {click_button submit}.not_to change(User, :count)
  end

  scenario "with valid information" do
    fill_in "Name",         with: "test name"
    fill_in "Email",        with: "test@test.com"
    fill_in "Password",     with: "password"
    fill_in "Confirmation", with: "password"
    expect {click_button submit}.to change(User, :count).by(1)
  end
end

您必须删除it，因为scenario 只是it 的别名，您也不​​能嵌套it。

或者，如果您发现它更具可读性，您可以随时切换回旧的 DSL。在那种情况下，我会这样做：

describe "sign-up" do
  before {visit signup_path}
  let(:submit) {"Create my account"}

  context "with invalid information" do
    it "does not create a user" do
      expect {click_button submit}.not_to change(User, :count)
    end
  end

  context "with valid information" do
    before
      fill_in "Name",         with: "test name"
      fill_in "Email",        with: "test@test.com"
      fill_in "Password",     with: "password"
      fill_in "Confirmation", with: "password"
    end
    it "creates a user" do
      expect {click_button submit}.to change(User, :count).by(1)
    end
  end

end

但只要规范检查了它必须检查的内容，无论如何你应该没问题。其余的都是风格、可读性和良好实践的问题，这些很重要，但更容易引起讨论和分歧。在这种情况下，gem 的作者不允许嵌套feature。也许是为了可读性，或者可能觉得不需要它，或者可能没有考虑过......如果你真的想嵌套功能，你可以随时尝试实现它并拉取请求。