ruby - Rspec - 如何 stub 第 3 方异常

Question

我正在尝试测试我是否能够捕获这些 AWS 异常:

begin
  s3_client = S3Client.new
  s3_file = s3_client.write_s3_file(bucket, file_name, file_contents)
rescue AWS::Errors::ServerError, AWS::Errors::ClientError => e
  # do something
end

我的 Rspec 3 代码:

expect_any_instance_of(S3Client).to receive(:write_s3_file).and_raise(AWS::Errors::ServerError)

但是当我测试这个 stub 时，我得到一个类型错误:

exception class/object expected

我必须包括 AWS::Errors::ServerError 吗？如果是这样，我该怎么做？我正在使用 aws-sdk-v1 gem。

谢谢。

Answer 1

我会构建一个端口，然后注入(inject)一个即将向您抛出错误的 stub 对象。让我解释一下:

class ImgService
  def set_client(client=S3Client.new)
    @client = client
  end

  def client
    @client ||= S3Client.new
  end

  def write(bucket, file_name, file_contents)
    begin
      @client.write_s3_file(bucket, file_name, file_contents)
    rescue AWS::Errors::ServerError, AWS::Errors::ClientError => e
      # do something
    end
  end
end

测试:

describe "rescuing an AWS::Error" do
  before :each do
    @fake_client = double("fake client")
    allow(@fake_client).to receive(:write_s3_file).and_raise(AWS::Errors::ServerError)

    @img_service = ImgService.new
    @img_service.set_client(@fake_client)
  end
  # ...
end