rspec 一次构建多个测试，记忆变量有问题

Question

我需要构建一些非常重复的 rspec 测试，并想稍微干燥一下。

describe 'filter' do
  let!(:filter_1) { create :filterable, value: 1 }
  let!(:filter_2) { create :filterable, value: 2 }
  let!(:filter_3) { create :filterable, value: 3 }
  let!(:filter_4) { create :filterable, value: 4 }

  expected = { 
              a: filter_1,
              b: filter_2,
              c: filter_3,
              d: filter_4
            }
  expected.each do |filter, expected| 
    describe "by #{filter}" do
      let(:expected) { [ expected ] }
      it "shows only #{filter}" do
        get :index, filter: filter
        expect(assigns[:filters]).to match_array expected
      end
    end
  end
end

我主要是用我的过滤器和预期结果定义一个散列，然后为每个过滤器构建一个测试。

问题是如何在散列中指定预期结果。

此示例引发错误：

rspec-core-3.4.4/lib/rspec/core/example_group.rb:667:in `method_missing': `filter_1` 
is not available on an example group (e.g. a `describe` or `context` block). 
It is only available from within individual examples (e.g. `it` blocks) 
or from constructs that run in the scope of an example (e.g. `before`, `let`, etc). 
(RSpec::Core::ExampleGroup::WrongScopeError)```

I think the memoized variables are only available within an `it` block. 

how could I solve this? 

thanks,

Answer 1

describe 'filter' do
  expected_filters = -> () do
    filter_1 =  '1'
    filter_2 = '2'
    { a: filter_1, b: filter_2 }
  end
  
  

  expected_filters.().each do |filter, expected| 
    describe "by #{filter}" do
      it "shows only #{filter}" do
        expect(filter).to be_instance_of(Symbol)
        expect(expected).to be_instance_of(String)
      end
    end
  end
end

但是如果您需要 Let! 中的代码是运行对于任何示例，请尝试找到具有方法定义的解决方案，但您必须按实际情况更改测试代码中的某些内容。

rspec 一次构建多个测试，记忆变量有问题

rspec build many tests at once with each, problem with memoized variables

unit-testing

rspec