Getting 100% coverage is of dubious utility. I'm usually happy if I'm >85%.

A while back, I was writing an important new application for my company. It would often send out e-mails, and I had coded the mail-sending module to send e-mail via our mail server, with the user's e-mail address on the To and/or From lines. While testing it, we had always used e-mail addresses within our own domains.

On release, no e-mail was being sent. I soon figured out why: the mail server considred the web server an external host, and since it was (correctly) not configured to be an open relay, it would drop the mail when the domain portion of the From address wasn't one of our domains.

If we had been using TDD (which we aren't due to political reasons), we potentially could have shown 100% coverage with Devel::Cover and never caught this bug. The e-mail addresses used in the tests would have almost certainly been internal ones. Only a developer experianced with this Gotcha would have caught it before release.

"There is no shame in being self-taught, only in not trying to learn in the first place." -- Atrus, Myst: The Book of D'ni.

In reply to Re: OT: TDD question by hardburn
in thread OT: TDD question by dragonchild

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