Re: Testing a class which utilizes randomness

>
> no two strings are ever the same.
>>
>
> Ever?  Is that even possible?
>


What does close enough mean? Can they be UUIDs and GUIDs and be "close
enough"? Or do they need to be *random* and non-repeating?


> 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?
>>
>
by separating concerns.

You have string generation.
You have duplicate rejection.

You can test duplicate rejection with a mock string generator.

You can test randomness of string generations.... aw, heck, looks like you
need stats and algo gurus. Math, not a billion unit tests for the algorithm.



-- 
Tim Ottinger, Sr. Consultant, Industrial Logic
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