Improve and fix testing for commands.
Review Request #13071 — Created May 25, 2023 and submitted
Our command testing support has been pretty under-utilized so far. While
working on some new tests, I encountered some crashes that could occur
if setting up two command runs in one test.
This change fixes that, along with some unbound variables. It also adds:
- Full typing throughout the command test helpers
- JSON output in the command results
- Generics for the test helper class, to help type instances of the
Upcoming tests will use this support.
Unit tests pass.
Tested with in-progress changes.