我正在尝试测试 Rails 记录器是否接收到我的某些规范中的消息。我正在使用 Logging gem。
假设我有这样的课程:
class BaseWorker
def execute
logger.info 'Starting the worker...'
end
end
和一个像这样的规范:
describe BaseWorker do
it 'should log an info message' do
base_worker = BaseWorker.new
logger_mock = double('Logging::Rails').as_null_object
Logging::Rails.stub_chain(:logger, :info).and_return(logger_mock)
logger_mock.should_receive(:info).with('Starting the worker...')
base_worker.execute
Logging::Rails.unstub(:logger)
end
end
我收到以下失败消息:
Failure/Error: logger_mock.should_receive(:info).with('Starting worker...')
(Double "Logging::Rails").info("Starting worker...")
expected: 1 time
received: 0 times
我尝试了几种不同的方法来让规范通过。这适用于例如:
class BaseWorker
attr_accessor :log
def initialize
@log = logger
end
def execute
@log.info 'Starting the worker...'
end
end
describe BaseWorker do
it 'should log an info message' do
base_worker = BaseWorker.new
logger_mock = double('logger')
base_worker.log = logger_mock
logger_mock.should_receive(:info).with('Starting the worker...')
base_worker.execute
end
end
但是必须设置一个这样的可访问实例变量似乎在这里摇尾巴。 (实际上,我什至不确定为什么将 logger 复制到 @log 会使其通过。)
什么是测试日志记录的好解决方案?
虽然我同意您通常不想测试记录器,但有时它可能很有用。
我对 Rails.logger
的期望取得了成功。
使用 RSpec 已弃用的 should
语法:
Rails.logger.should_receive(:info).with("some message")
使用 RSpec 较新的 expect
语法:
expect(Rails.logger).to receive(:info).with("some message")
注意:在控制器和模型规范中,您必须在记录消息之前放置此行。如果你把它放在后面,你会收到这样的错误消息:
Failure/Error: expect(Rails.logger).to receive(:info).with("some message")
(#<ActiveSupport::Logger:0x007f27f72136c8>).info("some message")
expected: 1 time with arguments: ("some message")
received: 0 times
使用 RSpec 3+ 版本
包含单次调用 Rails.logger.error
的实际代码:
Rails.logger.error "Some useful error message"
规格代码:
expect(Rails.logger).to receive(:error).with(/error message/)
如果您希望在规范运行时实际记录错误消息,请使用以下代码:
expect(Rails.logger).to receive(:error).with(/error message/).and_call_original
包含多次调用 Rails.logger.error
的实际代码:
Rails.logger.error "Technical Error Message"
Rails.logger.error "User-friendly Error Message"
规格代码:
expect(Rails.logger).to receive(:error).ordered
expect(Rails.logger).to receive(:error).with(/User-friendly Error /).ordered.and_call_original
此外,如果您只关心匹配第一条消息而不是任何后续消息,那么您可以使用以下
expect(Rails.logger).to receive(:debug).with("Technical Error Message").ordered.and_call_original
expect(Rails.logger).to receive(:debug).at_least(:once).with(instance_of(String)).ordered
注意上述变体设置 .ordered
很重要,否则期望设置开始失败。
参考:
http://www.relishapp.com/rspec/rspec-mocks/v/3-4/docs/setting-constraints/matching-arguments
http://www.relishapp.com/rspec/rspec-mocks/v/3-4/docs/setting-constraints/message-order
而不是在记录消息之前使用此行:
expect(Rails.logger).to receive(:info).with("some message")
something that triggers the logger...
您可以将 Rails 记录器设置为间谍并改用 have_received
:
allow(Rails.logger).to receive(:info).at_least(:once)
something that triggers the logger...
expect(Rails.logger).to have_received(:info).with("some message").once
expect(Rails.logger).to receive(:info).with("A Report processing is already scheduled for: #{report.inspect}")
给出了这个错误:expected: ("A Report processing is already scheduled for: #<Report id: 2677, org_id: 6649, user_id: ...tion: nil, life_state: \"ideation\", chat_link: nil, discarded_at: nil, registrants_count: 2>") ---> got: ("A Report processing is already scheduled for: [#<Report id: 2677, org_id: 6649, user_id:...ion: nil, life_state: \"ideation\", chat_link: nil, discarded_at: nil, registrants_count: 2>]") (1 time)
如果您的目标是测试日志记录功能,您还可以考虑验证输出到标准流。
这将使您免于模拟过程并测试消息是否会真正到达它们应该到达的位置(STDOUT/STDERR)。
使用 RSpec 的 output matcher(在 3.0 中引入),您可以执行以下操作:
expect { my_method }.to output("my message").to_stdout
expect { my_method }.to output("my error").to_stderr
对于 Logger
或 Logging
等库,您可能必须使用 output.to_<>_from_any_process
。
_from_any_process
是我所缺少的!花了太长时间才找到这个。谢谢!
如果您想在测试中保持一致性,但最后设置期望值,您需要在设置中添加:
setup do
allow(Rails.logger).to receive(:info)
end
...
it 'should log an info message' do
{code}
expect(Rails.logger).to have_received(:info).with('Starting the worker...')
end
即使我有非常相似的错误:
Failure/Error: expect(Rails.logger).to receive(:info).with("some message")
(#<ActiveSupport::Logger:0x007f27f72136c8>).info("some message")
expected: 1 time with arguments: ("some message")
received: 0 times
以下对我有用,
expect { my_method }.
to output(/error messsage/).to_stdout_from_any_process
参考:https://relishapp.com/rspec/rspec-expectations/docs/built-in-matchers/output-matcher
不定期副业成功案例分享
expect(Rails.logger).to receive(:info).with(/partial_string/)
其中“partial_string”是您要查找的字符串。简单的正则表达式比较expect(Rails.logger).to_not receive(:error).with(anything)
it
块甚至运行之前在我的let
表达式中完成的内容中记录的消息