writing unit test for calc functions

Hey guys,

so once again I was bit by our missing systematic unit tests for all the
formula functions. I'm wondering what we can do to make external people
interested in adding tests for all functions. Right now I think that my csv
based approach is too complicated (how to handle precision issues, ...) and
I wonder if it makes sense to switch from such an approach to a pure
spreadsheet approach.

So for each function creating a spreadsheet with a summary sheet that
contains one cell with a true false return value. This would mean that
writing the test is purely creating a spreadsheet and all the error
checking happens inside of the spreadsheet. The test would only open the
document, force a hard recalc and check that one cell.

Basically I'd like to have for each spreadsheet function a document that
checks all corner cases and can be used for manual testing as well as for
automated testing.

Does that make sense?

@Winfried: You are writing most of the spreadsheet functions right now.
Would that be something that would help you add tests for all new
functions? You could add your test cases directly in the spreadsheet and
use it for manual checking as well as later for an automated test.

@Eike: You are fixing most of the corner cases in the interpreter. Do you
think that this is better than our current ucalc based approach for bug
fixing?

@QA team: Does this sound like something that would make it easier for you
to add tests for spreadsheet functions?

I'm also open to alternative ideas or people telling me that it is a stupid
idea.

Regards,
Markus