rspec let，如何取消设置属性

Question

我有以下规格：

describe Country do
  let (:country) { Country.new(:country_code => "NL", :name => "Netherlands") }
  context "when country code is empty" do
  let (:country) { Country.new(:name => "Netherlands") }
    it "should not be valid" do
      expect(country.valid?).to be_falsey
    end
    it "should not save" do
      expect(country.save).to be_falsey
    end    
  end
  context "when country code is not empty" do
    let (:country) { Country.new(:country_code => "NL") }
    it "should be valid" do
      expect(country.valid?).to be_truthy
    end
    it "should save" do
      expect(country.save).to be_truthy
    end
  end
  context "when name is empty" do
    it "should not be valid" do
      expect(country.valid?).to be_falsey
    end
    it "should not save" do
      expect(country.save).to be_falsey
    end
  end

end

end

我想实现的是 let 方法中的"取消设置"属性。理想情况下，我想：

let (:country) { country.country_code = nil }

我想这样做是因为我想测试Country的单个属性是否存在（和 NON 存在），同时保持其他属性的设置。

Answer 1

有很多方法可以做到这一点。

1. 您可以在每个上下文中使用#before：

   before do country.code = nil #change this in another context to a non-empty code end

2. 或者，您可以将顶级 let 更改为引用country_code let，如下所示：

   let (:country) { Country.new(:country_code => country_code, :name => "Netherlands") }

   #immediately after context "when country code is empty" let(:country_code) { nil }

   ..... #immediately after: context "when country code is not empty" do let (:country_code) { "NL" }

   如果您的context "when name is empty需要 country_code ，则将顶级代码定义为默认值。

因此，您的代码可能如下所示：

  describe Country do
  let (:country) { Country.new(:country_code => country_code, :name => "Netherlands") }
  let(:country_code) { "NL" } #default
  context "when country code is empty" do
    let (:country_code) { nil } 
    it "should not be valid" do
      expect(country.valid?).to be_falsey
    end
    it "should not save" do
      expect(country.save).to be_falsey
    end    
  end
  context "when country code is not empty" do
    let (:country_code) {  "NL" }
    it "should be valid" do
      expect(country.valid?).to be_truthy
    end
    it "should save" do
      expect(country.save).to be_truthy
    end
  end
  context "when name is empty" do
    it "should not be valid" do
      expect(country.valid?).to be_falsey
    end
    it "should not save" do
      expect(country.save).to be_falsey
    end
  end

end

end

Answer 2

对于应该在任何it之前执行的特定操作，您必须使用 before 钩子块，并将:all键传递给方法。它允许为上下文块准备一次测试：

describe "when country code is not empty" do
   before(:all) { country.country_code = nil }
   # ...
end

注意我用describe关键字来对付context。但：

根据 rspec 源代码，"上下文"只是"描述"的别名方法......

"描述"的目的是针对一个功能包装一组

测试，而"上下文"是在同一状态下针对一个功能包装一组测试。

有关describe与context的详细信息，请参阅文章：在 RSpec 中描述与上下文。

您也可以使用before上下文块：

before(:context) { country.country_code = nil }
context "when country code is not empty" do
   # ...
end