I used to maintain Debian packages. As far as I know (or could find looking through the Policy manual and a few language-specific packaging guidelines), there is no policy against running tests after builds. I spent a few minutes looking through several packages and didn't see any that ran tests, but I have seen bug reports about test failures. If there are tests and they run using a reasonable amount of resources, I can't imagine anyone would argue against running them. The package maintainer has to do it, and I assume that some mess up.
