If --shuffle was not passed to resmoke.py, and you specified more than one test via the command line, then we should run the tests in the order specified. For example

python buildscripts/resmoke.py jstests/core/where2.js jstests/core/find1.js jstests/core/explain1.js

Should run where2.js, then find1.js, then explain1.js. Of course, if you're running with multiple jobs, the best it can do is to put them in the queue in that order.

It looks like the order isn't preserved because the logic in buildscripts/resmokelib/selector.py uses a set to compute which tests should be run, losing the original order.