Re: Testing a class which utilizes randomness

Hello!

Thanks everyone for your replies. Like I said, I'm not testing the RNG (or
RSG in this case), but rather the algorithm which deals with duplicates.
I'll go with what David and John suggested, writing a class to generate
unique random strings and injecting a random string generator.
Interesting how a TDD approach resulted in code being organized properly.
If I hadn't used it, I'd probably have written a method that used an
embedded random string generator and would never have given the problem a
second thought.

Thanks for the help,
Nikola



On Fri, Apr 4, 2014 at 8:52 PM, Steven Gordon <[email protected]> wrote:

>
>
> Agreed.
>
> Already suggested that the" history" object is what needs to be TDD-ed.
>
> The fact that randomness is not a good candidate for TDD-ing is just an
> interesting side-note.
>
>
> On Fri, Apr 4, 2014 at 11:50 AM, Ron Jeffries <[email protected]> wrote:
>
>>
>>
>> I'm pretty sure OP is trying to learn how to TDD, not how to create
>> really great random strings.
>> :)
>> R
>>
>> On Apr 4, 2014, at 2:48 PM, Steven Gordon <[email protected]> wrote:
>>
>> This project is presumably using an RNG rather than coding one.
>>
>> The criteria that matters would be whether the strings being generated
>> (using an RNG) is sufficiently random, not whether the sequence of numbers
>> that are being used to generate those strings are sufficiently random.
>>
>> It is quite possible for the RNG to be random enough, but the strings to
>> not be.  For example, the long term behavior of the random number generator
>> could always create a nice random distribution on bins, but that
>> subsequences are not as random. If each string would be created by a
>> subsequence rather than individual number, then they would not be random
>> enough.
>>
>> It could make a difference whether or not the size of the character set
>> is prime.
>>
>>
>>
>> Ron Jeffries
>> www.XProgramming.com <http://www.xprogramming.com>
>> I know we always like to say it'll be easier to do it now than it
>> will be to do it later. Not likely. I plan to be smarter later than
>> I am now, so I think it'll be just as easy later, maybe even easier.
>> Why pay now when we can pay later?
>>
>>
>  
>