/gempesaw/writing

I recently became the maintainer of Selenium::Remote::Driver, which is the Perl bindings to the Selenium Webdriver API. I just released version 0.18 to the CPAN and hopefully got the tests passing again :D.

I'm still trying to figure out the Best Way to test a module that is basically an interface to a ReST API. As far as I'm aware, integration testing these kinds of modules basically require you to mock or fake out network responses, but there were a couple articles on blogs.perl.org that discouraged the use of mocks, so I'm a bit unsure about best practices.

Test::LWP::UserAgent is one way to mock/fake out network traffic in Perl, and it's similar to AngularJS's $httpBackend: you instantiate a fake network object, and then tell it what requests it should expect. You inject the fake network object into your module's constructor, and when it tries to make a request, the mock catches it and lets you examine the request for tests and the like. You can also specify responses to test out the different branches of the module, like for error handling tests.

For a big module, having to set up tests for every single request can get a bit cumbersome, so S::R::D went the way of simply recording all of the requests/responses that its test suite makes, and including the recordings with the module. When running the tests, it loads up the recording and matches incoming requests to its list of recorded REQ/RES pairs, and returns the appropriate response.

Unfortunately, the recording process is different across platforms, so every change to the module or the tests require new recordings for each supported platform. Additionally complicating the issue was that there was a bug somewhere in the recording code, so it would only work with an LWP-Protocol-PSGI-0.04, which is the module used to record the requests and responses.