ruby-on-rails - VCR 在第二次尝试运行测试时抛出无法处理请求(第一次尝试通过)

Question

我设置了 VCR，它可以在我编写的多个测试中运行，没有问题。我尝试编写的最新测试将在第一次运行时通过，但之后将一直失败，除非我删除磁带。测试代码为:

it "doesn't blow up if a user doesn't have billing info" do
    VCR.use_cassette('tax_reconciler/no_method_error')do
      user_guid = rand(10000000)
      CreateRecurlyTestData.create_account(user_guid, nil, nil)
      tax_reconciler = TaxReconciler.new
      new_tax_amount = rand(100000)
      user = create_test_user(:guid => user_guid)
      expect(tax_reconciler.update_tax_amount(user, new_tax_amount)).to_not raise_error
    end
  end

错误信息如下:

失败/错误:CreateRecurlyTestData.create_account(user_guid, nil, nil) VCR::Errors::UnhandledHTTPRequestError:

   ================================================================================
   An HTTP request has been made that VCR does not know how to handle:
     GET https://2b64d08ef45c446dbba75720a37b7d41:@api.recurly.com/v2/accounts/3276643

   VCR is currently using the following cassette:
     - /Users/Evan/dish/stallone/fixtures/vcr_cassettes/tax_reconciler/no_method_error.yml
     - :record => :once
     - :match_requests_on => [:method, :uri]

   Under the current configuration VCR can not find a suitable HTTP interaction
   to replay and is prevented from recording new requests. There are a few ways
   you can deal with this:

     * If you're surprised VCR is raising this error
       and want insight about how VCR attempted to handle the request,
       you can use the debug_logger configuration option to log more details [1].
     * You can use the :new_episodes record mode to allow VCR to
       record this new request to the existing cassette [2].
     * If you want VCR to ignore this request (and others like it), you can
       set an `ignore_request` callback [3].
     * The current record mode (:once) does not allow new requests to be recorded
       to a previously recorded cassette. You can delete the cassette file and re-run
       your tests to allow the cassette to be recorded with this request [4].
     * The cassette contains 4 HTTP interactions that have not been
       played back. If your request is non-deterministic, you may need to
       change your :match_requests_on cassette option to be more lenient
       or use a custom request matcher to allow it to match [5].

   [1] https://www.relishapp.com/vcr/vcr/v/2-9-3/docs/configuration/debug-logging
   [2] https://www.relishapp.com/vcr/vcr/v/2-9-3/docs/record-modes/new-episodes
   [3] https://www.relishapp.com/vcr/vcr/v/2-9-3/docs/configuration/ignore-request
   [4] https://www.relishapp.com/vcr/vcr/v/2-9-3/docs/record-modes/once
   [5] https://www.relishapp.com/vcr/vcr/v/2-9-3/docs/request-matching

spec helper 中唯一的配置选项是:

VCR.configure do |c|
    c.cassette_library_dir = 'fixtures/vcr_cassettes'
    c.hook_into :webmock # or :fakeweb
  end

Answer 1

您的 VCR 设置配置为录音模式 :once: https://www.relishapp.com/vcr/vcr/v/1-8-0/docs/record-modes/once

简而言之，它只在没有卡带的情况下记录请求。对于后续运行，它只会读取记录的请求，因此与任何记录的请求都不匹配的请求将引发此错误。

此模式出现问题的一种常见方式是，如果您删除卡带并且只运行一个规范，而不是整个套件。 Bingo - 您的磁带已创建，除该特定规范中的请求外，所有请求都将无法识别。

此模式的一个好处是您可以捕获虚假请求 - 如果您知道您的磁带包含所有有效请求，则可以使用此模式捕获由于不正确请求而导致的错误。

如果你想更灵活，可以使用录制模式new_episodes。在此模式下，已识别的请求将从磁带中重播，未识别的请求将被执行并记录。