Conditional Post-Build step in Jenkins (Ideally without plugins)

If I understand correctly I can make a build step conditional using this plugin:

First does this plugin work the Post-Build steps?
Second is there a way to make Post-Build steps conditional without a plugin?

The scenario I have is I am supporting both WebDriver and Selenium IDE tests with one universal Jenkins Job setup. If they have checked in either type of test it runs them. I then want it to conditionally look if any results files show up and if so then do the publish results Post-Build step, otherwise skip that step.

Currently if no results show up it simply marks the build as a failure since no test results were found.

Any suggestions would help!

Git Baby is a git and github fan, let's start git clone.