RSpec:is_expect与Expect之间的区别

时间:2018-11-28 15:29:31

标签: ruby-on-rails ruby rspec rspec-rails

我在这里有两个规格:

it 'is not an included preferred gender' do
  house.preferred_gender = 3
  is_expected.not_to be_valid
end

it 'is an included preferred gender' do
  house.preferred_gender = 2
  expect(house).to be_valid
end

我不明白的是,如果我在第二个规范expect(house).to be_valid中替换了is_expected.to be_valid,那么我的测试将失败:

失败:

1) House preferred gender is an included preferred gender
     Failure/Error: is_expected.to be_valid
       expected #<House id: nil, rent: nil, deposit: nil, description: nil, preferred_gender: nil, created_at: nil, updated_at: nil, available_at: nil, user_id: nil, lease_length: nil, built_in: nil> to be valid, but got errors: User must exist, Rent can't be blank, Rent is not a number, Preferred gender can't be blank, Preferred gender is not included in the list, Available at can't be blank
     # ./spec/models/house_spec.rb:94:in `block (3 levels) in <main>'

Finished in 16.27 seconds (files took 3.02 seconds to load)
52 examples, 1 failure

为什么会这样? 提前非常感谢!

1 个答案:

答案 0 :(得分:2)

  

is_expected被简单地定义为Expect(subject),并且是为您使用带有新的基于Expect的语法的rspec-expectations时设计的。

https://relishapp.com/rspec/rspec-core/docs/subject/one-liner-syntax

由于被测对象是house而不是subject,因此我假设subject未初始化,因此设置为默认(described_class.new)。 is_expected对此默认主题发出了期望。

要使用is_expected,请初始化主题:

describe House do
   subject { House.new(...) } # or build :house if you use FactoryBot
   # ...
end