[crossfire] Unit tests

[Mark Wedel]

  While what tchize says about writing unit tests make sense, I'm also a little 
skeptical that it will actually get done in the way described and/or have other 
bad effects.

  For example, if there is the requirement that a unit test be written to 
test/confirm bug fixes, I could see it leading some people say they don't really 
want to spend the time to write such a test when the fix itself is trivial.  And 
then they don't fix the bug.

  Likewise, while writing unit tests before any large changes are done, I know 
from my experience finding time to actually code the change and do basic testing 
is difficult.  If it now takes 50% longer because unit tests also have to be 
written, that has various implications.

  In my ideal world, I'd love for there to be unit tests for everything.  I'm 
just not sure what level we can really achieve.  If we create/enforce draconian 
policies, I think the more likely scenario is people just stop writing new code, 
and not that they write unit tests (and/or they fork the code to a version such 
that they don't have to write unit tests).

  I'm certainly not saying unit tests are a bad thing.  But I think we have to 
keep in mind the people who are likely to write the tests.

  All that said, quick thoughts:

1) Basic function/API tests should be easy to write in most cases (if I call 
xyz(a,b) does it do the right thing).  Those shouldn't be much an issue.

2) A lot of the code operates on extensive external state (map data, archetypes, 
etc).  So to test the function, you need to have a map set up in the right way 
(right objects on the map, etc).

  In this case, you want something that makes such a test easy.  What may be 
easiest is in fact just a large set of test maps, and the unit test could 
effectively hard code those, with known coordinates (test object being only 
object at 0,0 and I know I want to insert that at 5,5)

  My thinking here is that if I can write the basic test to reproduce the bug in 
<10 minutes, I'll probably write the test.  IF the framework is such that it 
will take me an hour, then I probably wouldn't.

3) If the number of tests grow, it is probably desirable to be able to run some 
specific subset of tests, eg, I don't want to have to wait 15 minutes for the 
server to run all the tests when I'm trying to fix some specific bug - I just 
want it to run my test.  After all is done, then perhaps running all tests 
before commit makes sense.