Re: Testing IS Development

[moritz]

As a humble contributor to an open source project of which I've only grasped a small part, a test suite also gives me one things: confidence.

When I changed something, and the test suite doesn't show a new failure, then I can be pretty sure that my patch doesn't screw up things very badly.

Without this confidence I would hesitate much more before to send patches, let alone push changes to a repository directly.

These days I regularly contribute to Rakudo (a Perl 6 compiler), and we don't close any bug reports unless there are tests for them in the test suite. As a consequence the number of reported regressions clearly decreased, while areas that can't be tested yet (due to limitations in our tools) still regress now and then.

So apart from confidence the confidence also makes me proud, because I know that our product is of good quality.

Don't underestimate the benefits of these "soft" advantages, especially when the project is driven by volunteers. If they don't feel good during development for too long, they'll simply jump off and look for a different project. Having a test suite to ward off frustrating experiences is a way to keep them on board.