Why think unit tests should be in their own source code hierarchy instead of side-by-side

[Alexandru Ermicioi]

On Thursday, 22 March 2018 at 11:19:46 UTC, Basile B. wrote:
> On Thursday, 22 March 2018 at 11:00:31 UTC, Atila Neves wrote:
>> On Thursday, 22 March 2018 at 10:59:56 UTC, Atila Neves wrote:
>>> Blog post:
>>>
>>> https://atilanevesoncode.wordpress.com/
>>>
>>> Atila
>>
>> Direct link:
>>
>> https://atilanevesoncode.wordpress.com/2018/03/22/keep-d-unittests-separated-from-production-code/
>>
>> Sorry for the forum spam.
>>
>> Atila
>
> I don't agree at all. Everything is so much faster when 
> unittest blocks are in the same module as the stuff that are 
> tested. Generally i think that it makes things easier.

It's easier, true. But not all code can be nicely unittested 
using small chunks of unittests near the actual code. Consider 
unittested objects/structs, in each unittest you'll have to 
instantiate and stuff with mocks if needed and test a small piece 
of functionality from them. Also there is a problem with mocked 
objects where they will go? If every bit of functionality will be 
tested in same module with source code, then unittest / line of 
actual code will be much more to unittests part. It will make 
your module hard to navigate and discover what your source code 
is actually doing. So having a separate module with unittests 
indeed will help in making more claner and more understandable 
since they won't interfere with actual code.