AC:

• use Python asyncio
  • file format for encoding processes to be launched (plain python fine)
  • output to different destinations: console, log file
• support multiple error handlers
  • ability to launch and tear down processes (local only)
  • a way designate tests in the file format
• separate launcher executable (launch) from launch file containing the process information
  • identify launch files by full path
• support nesting launch files
• example with multiple tests in a single file
  • module level setup / teardown with async launcher
  • test function running launcher and adding coroutine for the test
• ability to integrate with ament
• collect test results (or pass in test results directory) I don't think the launcher needs to know about it

The following bullets should be separated into a new ticket since they require external functionally to exist before they can be implemented:

• launch API: locate launch files in share/pkgname/launch
• launch executable: identify launch file by package name and launch file name

Future features after clarifying API needs:

• support registering global callbacks