Helper unit testing functions in Phobos (possible std.unittests)

[Jonathan M Davis]

I'm proposing a possible new module for phobos which would be called 
std.unittests. The code and DDoc file can be found here: http://is.gd/gLH9Q

Or you can look at the code here directly (though it has poor highlighting): 
http://ideone.com/EOlod

The module contains a set of helper functions for unit tests which are an 
improvement over simply using assert. I have them to be very helpful in the unit 
tests in my proposal for std.datetime. My unit tests are more concise, easier to 
read, and much easier to debug because of them. assertEqual() and 
assertExcThrown() have been particularly useful.

assert is a great tool, but simply telling you that an assertion failed is not 
as useful as telling you _how_ it failed, and a function like assertExcThrown() 
(which, as you may guess, asserts that a particular exception was thrown by a 
particular function call) really reduces the boiler plate code that you have to 
write for testing what it tests. So, I find such helper functions are extremely 
useful.

Because I have used them so extensively in std.datetime, they are pretty much 
either going to have to be added as a module to Phobos or added as private 
helper functions in std.datetime. Personally,  I think that they (or something 
very similar to them) merit being added as a new module in Phobos, which can be 
expanded upon as others come up with particularly useful unit testing functions.

So, I'm requesting that the folks here on the list have a look at my module and 
review it for possible inclusion in Phobos. I don't know what Andrei's position 
on them is (he rightly focused his review of my datetime code on the date/time 
functionality and API rather than its unit tests and didn't mention my unit 
testing functions at all), but I think that such a module would be of great 
worth and would like other's opinions on it.

- Jonathan M Davis