开云体育

Single Messages Topics Expanded Polls

Re: [TDD] Testing a class which utilizes randomness

Ron Jeffries All Messages By This Member #35506 开云体育 Hi Nikola, On Apr 4, 2014, at 5:29 AM, Nikola Novak <reasonsharp@...> wrote: I'm new to TDD and this group. For practice, I started a simple project and now I want to create a list of random strings, but such that no two strings are ever the same. In a very unlikely, yet possible case, when two randomly generated strings are the same, the method that does this should discard the duplicate and generate a new string before it returns. What I want to test is exactly this behavior - the code which discards the duplicate and forces the string to be regenerated. To test that, I need to force the random string generator to return a duplicate at least once (but finite number of times). To create the test which would generate strings until there's at least one duplicate is unrealistic, because such a test could take a very long time to complete. How would I write such a test? One could: Have a method boolean containsString(aString) and test that. Have a method putIfAbsent(aString) and test that (by putting the same string twice and observing that I still only have one string. Or something approximately like that. I generally try to avoid something like boolean putString(aString) that returns whether it accepted the string or not, because I try to avoid methods that return a value and do something. I might put up with it but probably not. There are more ways ... Ron Jeffries I have two cats, and a big house full of cat stuff.? The cats fight and divide up the house, messing up their own lives.? Nice work cats.? Meow.

#35506

Join [email protected] to automatically receive all group messages.