Rspec 测试方法的提升和救援

Question

有没有办法 rspec 测试是否引发并挽救了错误？如果我有救援，我的 rspec 测试不会看到引发的错误，只会导致救援？

module MyApp
  def some_method(msg)
     raise StandardError.new(msg)
  end

  def second_method(msg)
    begin
      count = 0
      some_method(msg)
    rescue StandardError=> e
      puts e
      count = 1
    end
  end
end

RSpec.describe Myapp do
  describe "#some_method" do
    it "should raise error" do
       expect {
        some_method("this is an error")
      }.to raise_error(StandardError) {|e|
        expect(e.message).to eql "this is an error"
      }
    end
  end

  # this fails, as the error is not raised
  describe "#second_method" do
    it should raise error and rescue do
      expect {
        a = second_method("this is an error and rescue")
      }.to raise_error(StandardError) {|e|
        expect(e.message).to eql "this is an error and rescue"
        expect(a) = 1
      }
    end
  end
end

Answer 1

您通常不想直接引发或挽救 StandardError，因为它提供的信息非常少，并且不会捕获 StandardError hierarchy 之外的错误。相反，您通常希望测试是否引发了特定异常，或者引发了特定错误类或错误消息。

如果您知道所需的自定义或built-in exception class，或特定的错误消息，请明确测试。例如：

it 'should raise an ArgumentError exception' do
  expect { MyApp.new.foo }.to raise_error(ArgumentError)
end

it 'should raise MyCustomError' do
  expect { MyApp.new.foo }.to raise_error(MyCustomError)
end

it 'should raise StandardError with a custom message' do
  msg = 'this is a custom error and rescue'
  expect { MyApp.new.foo }.to raise_error(msg)
end

如果您不知道（或关心）应该引发的特定异常或消息，但您希望 一些 异常会中断执行流程，那么您应该使用纯 @987654323 @匹配器。例如：

it "should raise an exception" do
  expect { MyApp.new.foo }.to raise_error
end