From: Ron Jeffries Date: 2001-12-15T21:50:50+09:00 Subject: [ruby-talk:28610] Re: John Roth dolt ( Re: A challenge to proponents of Unit Testing. ) On Sat, 15 Dec 2001 01:04:18 GMT, "David B Lightstone" wrote: >> >I mostly agree with this, and it bothers me that XP advocates don't seem >> >to pay much attention to coverage tools. >> >> The short reason, and I don't mean it to be curt, is that we are >> paying attention to defect detections, not to coverage. When defects >> slip through the net, we improve the net. > >Don't you kind of have a chicken and an egg situation here. Can't >observe a defect that slips thru the net without either conducting >an observation (aka test) or doing a code analysis. As near as I >can tell analysis only occurs when a defect is detected or >someone declares a need for a refactoring. We seem to be talking about two different things here or something. The original concern was about why we don't push coverage tools. (As I mentioned elsewhere, many teams do use them. XP does not in general push tools or techniques at that level: we trust and expect that people will use them if they are needed.) Coverage tools are not needed in general, I suggest, because teams can ship with low enough defect counts without them. If defects are not being detected downstream (that is, by testing outside the team or by users), then things are fine as they are. When defects are detected outside the team, then the team reflects on what happened and improves their process. The outcome is usually improvements to the programmer and customer test nets, and a better understanding of how to write tests. The outcome is often other process improvement, such as improved coding standards, coding tools, or testing tools (such as coverage). My point was that the driving element isn't coverage, it is defects. If too many are detected beyond the team, the team needs to improve its process. That process improvement might be to add coverage analysis. In my experience that's not one of the earliest choices made, and many teams deliver satisfactory quality without ever going there. Does that clarify what I was saying? Please recast your comment in that light so that I can respond better. Thanks, Ronald E Jeffries http://www.XProgramming.com http://www.objectmentor.com