[Scons-users] best practices: unit tests

[Mats Wichmann]

I have a few "is there a Best Known Method" type questions that I'll
dribble out over a few messages (that is, if I can keep my focus, I keep
getting dragged off onto other things).

This one has several interesting hits on the internet, to my
recollection - wiki pages, blogs, stackexchange, etc. The ones I've
looked at over several months didn't seem terribly comprehensive, though.

Unit tests are a key part of many software projects these days, and
often a part of acceptance criteria in code review systems. scons itself
follows this model - I see tests running every time you submit a pull
request on github.

What do people do here? Integrate the running of tests into the scons
builds? Keep them external?  If integrated, how?  On a smaller project I
suspect it could make sense to integrate the test tightly into the
build, such that a builder doesn't even report success until the
matching unit test has also passed - does anyone actually do that?  In a
more complex project, the ordering can get confusing: e.g. if several
different directories each build a shared library and a unit test
program for one shared library may require use of others of the shared
libraries, you can't bind it that simply.  What then - e.g. if you ought
to wait for the whole project to finish building before running the
various tests?  In the case of the project I'm working on, tests are
built with googletest, which is told on invocation to generate a result
file and the CI system swings through and collects the various result
files - thus the pass/fail decision is external to scons - but the
launching of the tests is not.  Indeed, it's big and complex enough that
running the unit tests is optional, which several of the CI builds do,
but a developer might not when testing a patch initially, as it could
slow them down too much.

Again... I realize that if it works, it's not wrong, I'm just curious
for thoughts on best practices, I assume others have had to think
through this question?