In a recent update on the GSOC-2015 projects for Moodle, Ramindu Deshapriya has submitted his work to the Project mentor Dan Marsden on Moorsp Plagiarism plugin.
The Moorsp plugin provides automated Behat and Unit tests for the core Moodle [Plagiarism_API]. Ramindu completed functions to leverage the plagiarism API and implemented behat and unit tests to cover these functions. The plugin uses the new [Event_2 Events API] instead of the older legacy log like the existing plagiarism plugins currently provide.
You can download the plugin from https://github.com/danmarsden/moodle-plagiarism_moorsp The github page also contains the installation instructions and procedure of running the tests.