At this point I'm already able to determine if website exists, so I finally have a need to get page content to read elements I'm interested in. So thats the task for today. First of all, I'll be using urls that have been already checked, so I believe I can skip tests that check for url related exceptions. My class that I'll test will be ContentRetriever which I'll introduce in the moment. There's only one test I want to complete here, as the class has only one responsibility - return page content as string. That means that I have to deal with some stream, to be more specific Stream that will come from my CustomWebResponse.
Test to accomplish my goal:
Now you may remember or lookup at previous post about HeaderRetriever. I decided to refactor it, extracting base class so it can be used in the way I need it. So the base class WebRetriever consists almost entirely of the class that I extracted it from. So right now what I need to do is derive from it, pass my method string to the constructor, instance of IWebRequestCreator and override abstract method HandleResponse which simply allows me to pick and return any part of the response I'll get.
Now to make test go green again, I simply did the steps I just mentioned and as the result got quite slim and even easier to read HeadRetriever:
At this point ContentRetriever was already piece of cake. One thing I've had to do in addition was the Stream property on my IHttpWebResponse.
And thats pretty much it for the production code. The test would pass, but again, I don't want to rely on the internet connection while testing. There's a functional test to check if it also works with real connection, but I need to mock it again. You probably already noticed that in the test I used some static members of WebRequestCreatorForContentStub class. That will probably need more refactoring as it can easily be connected with my creator for headers, but for now I'll just created another stub for IWebRequestCreator. The most important reason here was that I wanted to have some constant strings to rely on.
The last thing to make it work was a IHttpWebRequest stub that will allow me to get some made up stream from. Notice that for StreamWriter is enough to flush its buffer, disposing it would cause us to lose that precious stream.
Now the test passes without access to the internet and another step is complete. There's always some effort to put in those tests but I cannot overrate the feeling of having all the code under control by just looking on the list of green lights. Furthermore that implementation of ContentRetriever is safe for memory as it never will keep any stream alive more than it's necessary to read it and return content as string to process in the next step.
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