Re: [PATCH linux-kselftest/test v2] ext4: add kunit test for decoding extended timestamps

[Shuah Khan <skhan@linuxfoundation.org>]

On 10/17/19 5:54 PM, Tim.Bird@sony.com wrote:
> 
> 
>> -----Original Message-----
>> From: Iurii Zaikin
>>
>>> You can do all of this and allow users to supply another set of data.
>>> It doesn't gave to be one or the other.
>>>
>> What is the use case for running a unit test on a different data set than
>> what it comes with?
> 
> I just gave some ideas in another message (our emails crossed),
> but one use case is to allow someone besides the test author
> to inject additional data points, and to do so without having to re-compile
> the code.
> 

Right. Test author might not think about all the possible ways to
test.

> They might do this for multiple reasons:
>   - to experiment with additional data points
>   - to try to diagnose a problem they are seeing
>   - to fill gaps they see in existing data points
> 

Thanks for explaining the scenarios.

> Whether this makes sense depends on a lot of factors.  I suspect
> the timestamp test code is not a good candidate for this, as the code
> is simple enough that adding a new test case is pretty trivial.  For some
> other types of tests, adding the data via an external file could be easier
> than changing the code of the test.

I agree. Even if author thinks of all the different ways (I am convinced
of that), still taking test data at run-time makes the unit test just
more effective.

thanks,
-- Shuah