Break up me.psanders.ShortRouteFinder into testable components

[hxtk]

• Factory for matrix should take flags, a list of places, and a DistanceMatrixApiRequest object, modify that object based on the flags, and return a MatrixGraph<String, Long>

  • Mock DistanceMatrixApiRequest that fails to connect to the internet, i.e., throws ConnectException
  • Pass in a bad GeoApiContext, e.g., null, no API key, etc.
  • Mock that fails because the API key has exceeded its quota
  • Mock that works as expected

[hxtk]

Mock DistanceMatrixApiRequest that "works", i.e., produces a static matrix of the same size as the input list of places.

This matrix should be random, but it should not change across calls or even executions.

[hxtk]

Note: we'll have to mock System and inject it as a dependency, or else the calls to System.exit in our error cases will cause problems.

[hxtk]

It might be better to simply remove the calls to System.exit: Print the error messages, then return null values all the way back up the chain of command and let main handle program termination.