So I have a built and make tested tor-0.2.3.25/ folder and stem/ in a parallel folder. When I run the command then I get the following:
$ ./run_tests.py --integ Unable to start tor, 'tor' does not exists.
How can I run the tests on the Tor built in the tor-0.2.3.25/ folder?
Just run './run_tests.py --integ --tor /path/to/tor'. Without the '--tor' argument it uses the tor instance in your path (and you evidently don't have one).
Another argument that you might be interested in is '--target RUN_ALL' which will exercise all of the connection and authentication mechanisms. This'll take quite a while to run but provides the best test coverage. You can provide '--help' to see the other options.
Stem's integration tests were designed to test stem. Coincidentally they provide basic verification testing of Tor, though I'd love to see them be expanded to more dedicatedly test Tor! -Damian