exception - stub AWS SDK 函数以返回异常(自 SDK v. 2.1 起)

Question

我在规范中对 AWS SDK 调用使用 stub 响应，并且我始终能够 stub 带有异常的函数，然后根据情况测试它是否被适当捕获或引发。这将是迄今为止一直在工作的 MWE:

let(:aws_creds) { ::Aws::Credentials.new('a', 'b') }
let(:ec2_dummy_client) { ::Aws::EC2::Client.new(credentials: aws_creds, stub_responses: true) }

...

describe 'delete_vpc' do
  it 'raises on non-existent VPC' do
    ec2_dummy_client.stub_responses(:delete_vpc, Aws::EC2::Errors::InvalidVpcIDNotFound)
    expect{ec2_dummy_client.delete_vpc(vpc_id: "vpc-a08b44c5")}.to raise_exception(Aws::EC2::Errors::InvalidVpcIDNotFound)
  end
end

但是，自从从 AWS SDK 2.0 升级到 2.1 以来，我不断收到此(现实世界)错误:

 Failure/Error: expect{ec2_dummy_client.delete_vpc(vpc_id: "vpc-a08b44c5")}.to raise_exception(Aws::EC2::Errors::InvalidVpcIDNotFound)
   expected Aws::EC2::Errors::InvalidVpcIDNotFound, got #<ArgumentError: wrong number of arguments (0 for 2)> with backtrace:
     # ./spec/lib/backends/ec2_backend_spec.rb:691:in `block (5 levels) in <top (required)>'
     # ./spec/lib/backends/ec2_backend_spec.rb:691:in `block (4 levels) in <top (required)>'

我意识到我分配异常代替返回结构的方法一开始可能有点天真，尽管它有效。但是，正确的方法是什么？

Answer 1

事实证明，带有错误的 stub 函数是正确的方法，但 AWS 接口(interface)在 SDK v. 2.0 和 2.1 之间发生了变化。

一些错误(不是全部)现在是类 ServiceError，其构造函数需要两个强制属性:context 和 message。

对于一个简单的规范，只需初始化它们就足够了，这样问题中给出的 MWE 就可以像这样修复:

let(:aws_creds) { ::Aws::Credentials.new('a', 'b') }
let(:ec2_dummy_client) { ::Aws::EC2::Client.new(credentials: aws_creds, stub_responses: true) }

...

describe 'delete_vpc' do
  it 'raises on non-existent VPC' do
    ec2_dummy_client.stub_responses(:delete_vpc, Aws::EC2::Errors::InvalidVpcIDNotFound.new(Seahorse::Client::RequestContext.new,"VPC does not exist"))
    expect{ec2_dummy_client.delete_vpc(vpc_id: "vpc-a08b44c5")}.to raise_exception(Aws::EC2::Errors::InvalidVpcIDNotFound)
  end
end

请注意对 stub_responses() 调用中的 .new(...) 部分。