Add automated testing

It would be nice to integrate some automated testing into this tool to make sure that resolution and mapping continues to work, as well as documenting how this tool is intended to be used.

Start by locating the tool's resolution and mapping code and checking how the project is currently built or run. Define automated coverage for both areas, then document the intended usage of the tool. Done means the tests exercise resolution and mapping and the usage guidance is available in the project.

Written by the indexing model from the issue text.