It might be useful to add some tests for the shjs utility itself. This would include making sure it respects stdout/stderr and exit codes. This is less of a priority now, but would be more useful if #268 (stderr) and #252 (exit codes) are merged.

This would involve creating shelljs scripts and executing them with the shjs command, and making sure results are as expected. I don't think we need a large number of test cases, but we should have a few just to make sure we don't get regressions in the utility.