Suggestion (ping Walter): Improve unit testing.

[David B. Held]

Gregor Richards wrote:
> There are a number of improvements I'd like to see in D's unit testing 
> framework. All of them are standard library changes, and I've made them 
> work in Tango (as an external patch). If they were added to both Phobos 
> and Tango, DSSS could easily run unit tests, which would improve its 
> test suite.
> 
> Here are two major problems I see with unit tests right now:
> 1) You can't run only unit tests, you are forced to run main() as well.
> 2) Unit testing doesn't actually output anything useful, it just works 
> under the no-news-is-good-news principle.
> [...]

Yeah, these are good points.  There are a few things that you want from 
unit tests:

* Consistent design

This is already handled by the unittest mechanism, which is great. 
However, a unit testing library that offers all the typical primitives 
found in xUnit would be even greater.  This would help a lot in common 
reporting.

* Consistent invocation

This means that there is a standard, well-known way to run the tests. 
Typically 'make test' is a good way.  However, 'dmd -unittest foo.d' is 
also a perfectly good way, as is 'foo.exe --unittest'.  At any rate, it 
doesn't really make sense that unittests are just functions that get 
executed before main().  I'm pretty sure nobody expects that.

* Consistent output

This means that someone who has never seen your tests before can tell 
whether they passed or failed.  The problem with the 
'no-gnus-is-good-gnus' principle is that it makes it difficult to tell 
the difference between "the tests all passed" and "the tests didn't 
run".  Having a standard result summary makes it possible for automated 
tools to parse the results and display them in alternative formats.

Dave