如何在使用 rspec 测试 class 中的任何方法之前初始化一般上下文变量

Question

我是 rspec 的新手。我正在为服务 class 编写测试，我希望在任何描述块中运行之前初始化一堆实例。我做了类似的事情：

RSpec.describe MyService do
before :each do

    let(:product){create(:product)}
    let(:article_student){ create(:article, targets: [:student], vat_type: vat_type, product: product)} #target student
    let(:article_teacher){ create(:article, targets: [:teacher], vat_type: vat_type, product: product) }#target teacher
    # creer des offres
    let(:offer){create(:offer, target: :student, license_length: :m12)}
    let(:offer_special_cyclic){create(:offer_special, cyclic_amount: true, free_article_id: article_teacher.id, minimum_amount: 10, license_length: :m12)} # free article @article_teacher
    let(:offer_special_non_cyclic){create(:offer_special, cyclic_amount: false, free_article_id: article_teacher.id, minimum_amount: 10, license_length: :m12)} # free article @article_teacher
    let(:order){ create(:order, establishment_account: establis

hment_account)}
end

然后我将有几个 describe 块（测试 MyService 中的不同方法，我希望在每个方法中修改之前在 :each 块中创建的变量。例如：

  describe "#create_from_order" do
    subject{ licenses }
    context "first time worker runs" do
      order.already_went_through_license_worker = false
      order.save!
      LicenseService.new.create_from_order(@order.id)
      let(:licenses){ License.where(order_id: @order.id)}
      specify { subject.count.to eq 34 }
      specify { subject.pluck(:is_from_offer_special).count(true).to eq 4}
      specify { subject.pluck(:is_from_offer_special).count(false).to eq 30 }
end
end

然而，当我尝试运行我的测试时，我发现 context 块中的 order 未定义...

undefined local variable or method `order' for #<Class:0x007fc689ddfdb8>

我意识到我之前：每个代码都没有输入。实现此目的的好方法是在测试 class.

中的任何方法之前初始化一堆实例变量一般上下文

Answer 1

试试这个方法

RSpec.describe MyService do
  describe "#create_from_order" do
    let(:product){create(:product)}
    let(:article_student){ create(:article, targets: [:student], vat_type: vat_type, product: product)} #target student
    let(:article_teacher){ create(:article, targets: [:teacher], vat_type: vat_type, product: product) }#target teacher
    # creer des offres
    let(:offer){create(:offer, target: :student, license_length: :m12)}
    let(:offer_special_cyclic){create(:offer_special, cyclic_amount: true, free_article_id: article_teacher.id, minimum_amount: 10, license_length: :m12)} # free article @article_teacher
    let(:offer_special_non_cyclic){create(:offer_special, cyclic_amount: false, free_article_id: article_teacher.id, minimum_amount: 10, license_length: :m12)} # free article @article_teacher
    let(:order){ create(:order, establishment_account: establishment_account)}

    context "first time worker runs" do
      order.already_went_through_license_worker = false
      order.save!
      LicenseService.new.create_from_order(@order.id)
      let(:licenses){ License.where(order_id: @order.id)}
      specify { subject.count.to eq 34 }
      specify { subject.pluck(:is_from_offer_special).count(true).to eq 4}
      specify { subject.pluck(:is_from_offer_special).count(false).to eq 30 }
    end
  end
end

另外 let 方法运行如果只调用对象。如果你想让它无论如何都是运行，你应该使用let!方法。

希望对您有所帮助

Answer 2

首先，将您的 let 语句移出 before 块。 let 是延迟计算的，这意味着您定义的块 (let(:foo) { block }) 仅在调用 foo 时执行。但是通过将语句包装在 before 块中，您实际上并没有调用它们，因此什么也不会发生。

要在每个测试之前执行语句，请使用 let!。这不是惰性求值，并且会在您定义语句后立即执行，这正是您在本例中想要的。

RSpec.describe MyService do
  let!(:product){create(:product)}
  let!(:article_student){ create(:article, targets: [:student], vat_type: vat_type, product: product)} #target student
  let!(:article_teacher){ create(:article, targets: [:teacher], vat_type: vat_type, product: product) } #target teacher
  # creer des offres
  let!(:offer){create(:offer, target: :student, license_length: :m12)}
  let!(:offer_special_cyclic){create(:offer_special, cyclic_amount: true, free_article_id: article_teacher.id, minimum_amount: 10, license_length: :m12)} # free article @article_teacher
  let!(:offer_special_non_cyclic){create(:offer_special, cyclic_amount: false, free_article_id: article_teacher.id, minimum_amount: 10, license_length: :m12)} # free article @article_teacher
  let!(:order){ create(:order, establishment_account: establishment_account)}
end

现在，要修改对象，请在上下文中使用 before 块。并确保你没有混合 order 和 @order.

context "first time worker runs" do
  before do
    order.already_went_through_license_worker = false
    order.save!
    LicenseService.new.create_from_order(order.id)
  end

  let(:licenses){ License.where(order_id: order.id)}

  specify { subject.count.to eq 34 }
  specify { subject.pluck(:is_from_offer_special).count(true).to eq 4}
  specify { subject.pluck(:is_from_offer_special).count(false).to eq 30 }
end

这应该可以解决您的问题。

如何在使用 rspec 测试 class 中的任何方法之前初始化一般上下文变量

How to initialize general context variables before testing any methods within a class with rspec

ruby

rspec

ruby-on-rails

rspec-rails